System.Data.SQLite

//---------------------------------------------------------------------
// <copyright file="DmlSqlGenerator.cs" company="Microsoft">
//      Portions of this file copyright (c) Microsoft Corporation
//      and are released under the Microsoft Pulic License.  See
//      http://archive.msdn.microsoft.com/EFSampleProvider/Project/License.aspx
//      or License.txt for details.
//      All rights reserved.
// </copyright>
//---------------------------------------------------------------------

namespace System.Data.SQLite
{
  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.Globalization;
  using System.IO;
  using System.Text;
  using System.Data;
  using System.Data.Common;
  using System.Data.Metadata.Edm;
  using System.Data.Common.CommandTrees;
  using System.Data.Common.Utils;
  using System.Data.Mapping.Update.Internal;

  /// <summary>
  /// Class generating SQL for a DML command tree.
  /// </summary>
  internal static class DmlSqlGenerator
  {
    private static readonly int s_commandTextBuilderInitialCapacity = 256;

    internal static string GenerateUpdateSql(DbUpdateCommandTree tree, out List<DbParameter> parameters)
    {
      StringBuilder commandText = new StringBuilder(s_commandTextBuilderInitialCapacity);
      ExpressionTranslator translator = new ExpressionTranslator(commandText, tree, null != tree.Returning, "UpdateFunction");

      // update [schemaName].[tableName]
      commandText.Append("UPDATE ");
      tree.Target.Expression.Accept(translator);
      commandText.AppendLine();

      // set c1 = ..., c2 = ..., ...
      bool first = true;
      commandText.Append("SET ");
      foreach (DbSetClause setClause in tree.SetClauses)
      {
        if (first) { first = false; }
        else { commandText.Append(", "); }
        setClause.Property.Accept(translator);
        commandText.Append(" = ");
        setClause.Value.Accept(translator);
      }

      if (first)
      {
        // If first is still true, it indicates there were no set
        // clauses. Introduce a fake set clause so that:
        // - we acquire the appropriate locks
        // - server-gen columns (e.g. timestamp) get recomputed
        //
        // We use the following pattern:
        //
        //  update Foo
        //  set @i = 0
        //  where ...
        DbParameter parameter = translator.CreateParameter(default(Int32), DbType.Int32);
        commandText.Append(parameter.ParameterName);
        commandText.Append(" = 0");
      }
      commandText.AppendLine();

      // where c1 = ..., c2 = ...
      commandText.Append("WHERE ");
      tree.Predicate.Accept(translator);
      commandText.AppendLine();

      // generate returning sql
      GenerateReturningSql(commandText, tree, translator, tree.Returning);

      parameters = translator.Parameters;
      return commandText.ToString();
    }

    internal static string GenerateDeleteSql(DbDeleteCommandTree tree, out List<DbParameter> parameters)
    {
      StringBuilder commandText = new StringBuilder(s_commandTextBuilderInitialCapacity);
      ExpressionTranslator translator = new ExpressionTranslator(commandText, tree, false, "DeleteFunction");

      // delete [schemaName].[tableName]
      commandText.Append("DELETE FROM ");
      tree.Target.Expression.Accept(translator);
      commandText.AppendLine();

      // where c1 = ... AND c2 = ...
      commandText.Append("WHERE ");
      tree.Predicate.Accept(translator);

      parameters = translator.Parameters;

      commandText.AppendLine(";");
      return commandText.ToString();
    }

    internal static string GenerateInsertSql(DbInsertCommandTree tree, out List<DbParameter> parameters)
    {
      StringBuilder commandText = new StringBuilder(s_commandTextBuilderInitialCapacity);
      ExpressionTranslator translator = new ExpressionTranslator(commandText, tree, null != tree.Returning, "InsertFunction");

      // insert [schemaName].[tableName]
      commandText.Append("INSERT INTO ");
      tree.Target.Expression.Accept(translator);

      if (tree.SetClauses.Count > 0)
      {
        // (c1, c2, c3, ...)
        commandText.Append("(");
        bool first = true;
        foreach (DbSetClause setClause in tree.SetClauses)
        {
          if (first) { first = false; }
          else { commandText.Append(", "); }
          setClause.Property.Accept(translator);
        }
        commandText.AppendLine(")");

        // values c1, c2, ...
        first = true;
        commandText.Append(" VALUES (");
        foreach (DbSetClause setClause in tree.SetClauses)
        {
          if (first) { first = false; }
          else { commandText.Append(", "); }
          setClause.Value.Accept(translator);

          translator.RegisterMemberValue(setClause.Property, setClause.Value);
        }
        commandText.AppendLine(");");
      }
      else // No columns specified.  Insert an empty row containing default values by inserting null into the rowid
      {
        commandText.AppendLine(" DEFAULT VALUES;");
      }

      // generate returning sql
      GenerateReturningSql(commandText, tree, translator, tree.Returning);

      parameters = translator.Parameters;
      return commandText.ToString();
    }

    // Generates T-SQL describing a member
    // Requires: member must belong to an entity type (a safe requirement for DML
    // SQL gen, where we only access table columns)
    private static string GenerateMemberTSql(EdmMember member)
    {
      return SqlGenerator.QuoteIdentifier(member.Name);
    }

    /// <summary>
    /// Generates SQL fragment returning server-generated values.
    /// Requires: translator knows about member values so that we can figure out
    /// how to construct the key predicate.
    /// <code>
    /// Sample SQL:
    ///     
    ///     select IdentityValue
    ///     from dbo.MyTable
    ///     where @@ROWCOUNT > 0 and IdentityValue = scope_identity()
    /// 
    /// or
    /// 
    ///     select TimestamptValue
    ///     from dbo.MyTable
    ///     where @@ROWCOUNT > 0 and Id = 1
    /// 
    /// Note that we filter on rowcount to ensure no rows are returned if no rows were modified.
    /// </code>
    /// </summary>
    /// <param name="commandText">Builder containing command text</param>
    /// <param name="tree">Modification command tree</param>
    /// <param name="translator">Translator used to produce DML SQL statement
    /// for the tree</param>
    /// <param name="returning">Returning expression. If null, the method returns
    /// immediately without producing a SELECT statement.</param>
    private static void GenerateReturningSql(StringBuilder commandText, DbModificationCommandTree tree,
        ExpressionTranslator translator, DbExpression returning)
    {
      // Nothing to do if there is no Returning expression
      if (null == returning) { return; }

      // select
      commandText.Append("SELECT ");
      returning.Accept(translator);
      commandText.AppendLine();

      // from
      commandText.Append("FROM ");
      tree.Target.Expression.Accept(translator);
      commandText.AppendLine();

      // where
      commandText.Append("WHERE last_rows_affected() > 0");
      EntitySetBase table = ((DbScanExpression)tree.Target.Expression).Target;
      bool identity = false;
      foreach (EdmMember keyMember in table.ElementType.KeyMembers)
      {
        commandText.Append(" AND ");
        commandText.Append(GenerateMemberTSql(keyMember));
        commandText.Append(" = ");

        // retrieve member value sql. the translator remembers member values
        // as it constructs the DML statement (which precedes the "returning"
        // SQL)
        DbParameter value;
        if (translator.MemberValues.TryGetValue(keyMember, out value))
        {
          commandText.Append(value.ParameterName);
        }
        else
        {
          // if no value is registered for the key member, it means it is an identity
          // which can be retrieved using the scope_identity() function
          if (identity)
          {
            // there can be only one server generated key
            throw new NotSupportedException(string.Format("Server generated keys are only supported for identity columns. More than one key column is marked as server generated in table '{0}'.", table.Name));
          }
          commandText.AppendLine("last_insert_rowid();");
          identity = true;
        }
      }
    }

    /// <summary>
    /// Lightweight expression translator for DML expression trees, which have constrained
    /// scope and support.
    /// </summary>
    private class ExpressionTranslator : DbExpressionVisitor
    {
      /// <summary>
      /// Initialize a new expression translator populating the given string builder
      /// with command text. Command text builder and command tree must not be null.
      /// </summary>
      /// <param name="commandText">Command text with which to populate commands</param>
      /// <param name="commandTree">Command tree generating SQL</param>
      /// <param name="preserveMemberValues">Indicates whether the translator should preserve
      /// member values while compiling t-SQL (only needed for server generation)</param>
      internal ExpressionTranslator(StringBuilder commandText, DbModificationCommandTree commandTree,
          bool preserveMemberValues, string kind)
      {
        Debug.Assert(null != commandText);
        Debug.Assert(null != commandTree);
        _kind = kind;
        _commandText = commandText;
        _commandTree = commandTree;
        _parameters = new List<DbParameter>();
        _memberValues = preserveMemberValues ? new Dictionary<EdmMember, DbParameter>() :
            null;
      }

      private readonly StringBuilder _commandText;
      private readonly DbModificationCommandTree _commandTree;
      private readonly List<DbParameter> _parameters;
      private readonly Dictionary<EdmMember, DbParameter> _memberValues;
      private int parameterNameCount = 0;
      private string _kind;

      internal List<DbParameter> Parameters { get { return _parameters; } }
      internal Dictionary<EdmMember, DbParameter> MemberValues { get { return _memberValues; } }

      // generate parameter (name based on parameter ordinal)
      internal SQLiteParameter CreateParameter(object value, TypeUsage type)
      {
        PrimitiveTypeKind primitiveType = MetadataHelpers.GetPrimitiveTypeKind(type);
        DbType dbType = MetadataHelpers.GetDbType(primitiveType);
        return CreateParameter(value, dbType);
      }

      // Creates a new parameter for a value in this expression translator
      internal SQLiteParameter CreateParameter(object value, DbType dbType)
      {
        string parameterName = string.Concat("@p", parameterNameCount.ToString(CultureInfo.InvariantCulture));
        parameterNameCount++;
        SQLiteParameter parameter = new SQLiteParameter(parameterName, value);
        parameter.DbType = dbType;
        _parameters.Add(parameter);
        return parameter;
      }

      #region Basics

      public override void Visit(DbApplyExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");

        VisitExpressionBindingPre(expression.Input);
        if (expression.Apply != null)
        {
          VisitExpression(expression.Apply.Expression);
        }
        VisitExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbArithmeticExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionList(expression.Arguments);
      }

      public override void Visit(DbCaseExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionList(expression.When);
        VisitExpressionList(expression.Then);
        VisitExpression(expression.Else);
      }

      public override void Visit(DbCastExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbCrossJoinExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        foreach (DbExpressionBinding binding in expression.Inputs)
        {
          VisitExpressionBindingPre(binding);
        }
        foreach (DbExpressionBinding binding2 in expression.Inputs)
        {
          VisitExpressionBindingPost(binding2);
        }
      }

      public override void Visit(DbDerefExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbDistinctExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbElementExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbEntityRefExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbExceptExpression expression)
      {
        VisitBinary(expression);
      }

      protected virtual void VisitBinary(DbBinaryExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        this.VisitExpression(expression.Left);
        this.VisitExpression(expression.Right);
      }

      public override void Visit(DbExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        throw new NotSupportedException("DbExpression");
      }

      public override void Visit(DbFilterExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Input);
        VisitExpression(expression.Predicate);
        VisitExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbFunctionExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionList(expression.Arguments);
        //if (expression.IsLambda)
        //{
        //  VisitLambdaFunctionPre(expression.Function, expression.LambdaBody);
        //  VisitExpression(expression.LambdaBody);
        //  VisitLambdaFunctionPost(expression.Function, expression.LambdaBody);
        //}
      }

      public override void Visit(DbGroupByExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitGroupExpressionBindingPre(expression.Input);
        VisitExpressionList(expression.Keys);
        VisitGroupExpressionBindingMid(expression.Input);
        VisitAggregateList(expression.Aggregates);
        VisitGroupExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbIntersectExpression expression)
      {
        VisitBinary(expression);
      }

      public override void Visit(DbIsEmptyExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbIsOfExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbJoinExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Left);
        VisitExpressionBindingPre(expression.Right);
        VisitExpression(expression.JoinCondition);
        VisitExpressionBindingPost(expression.Left);
        VisitExpressionBindingPost(expression.Right);
      }

      public override void Visit(DbLikeExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpression(expression.Argument);
        VisitExpression(expression.Pattern);
        VisitExpression(expression.Escape);
      }

      public override void Visit(DbLimitExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpression(expression.Argument);
        VisitExpression(expression.Limit);
      }

      public override void Visit(DbOfTypeExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbParameterReferenceExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
      }

      public override void Visit(DbProjectExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Input);
        VisitExpression(expression.Projection);
        VisitExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbQuantifierExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Input);
        VisitExpression(expression.Predicate);
        VisitExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbRefExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbRefKeyExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbRelationshipNavigationExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpression(expression.NavigationSource);
      }

      public override void Visit(DbSkipExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Input);
        foreach (DbSortClause clause in expression.SortOrder)
        {
          VisitExpression(clause.Expression);
        }
        VisitExpressionBindingPost(expression.Input);
        VisitExpression(expression.Count);
      }

      public override void Visit(DbSortExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpressionBindingPre(expression.Input);
        for (int i = 0; i < expression.SortOrder.Count; i++)
        {
          VisitExpression(expression.SortOrder[i].Expression);
        }
        VisitExpressionBindingPost(expression.Input);
      }

      public override void Visit(DbTreatExpression expression)
      {
        VisitUnaryExpression(expression);
      }

      public override void Visit(DbUnionAllExpression expression)
      {
        VisitBinary(expression);
      }

      public override void Visit(DbVariableReferenceExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
      }

      public virtual void VisitAggregate(DbAggregate aggregate)
      {
        if (aggregate == null) throw new ArgumentException("aggregate");
        VisitExpressionList(aggregate.Arguments);
      }

      public virtual void VisitAggregateList(IList<DbAggregate> aggregates)
      {
        if (aggregates == null) throw new ArgumentException("aggregates");
        for (int i = 0; i < aggregates.Count; i++)
        {
          VisitAggregate(aggregates[i]);
        }
      }

      public virtual void VisitExpression(DbExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        expression.Accept(this);
      }

      protected virtual void VisitExpressionBindingPost(DbExpressionBinding binding)
      {
      }

      protected virtual void VisitExpressionBindingPre(DbExpressionBinding binding)
      {
        if (binding == null) throw new ArgumentException("binding");
        VisitExpression(binding.Expression);
      }

      public virtual void VisitExpressionList(IList<DbExpression> expressionList)
      {
        if (expressionList == null) throw new ArgumentException("expressionList");
        for (int i = 0; i < expressionList.Count; i++)
        {
          VisitExpression(expressionList[i]);
        }
      }

      protected virtual void VisitGroupExpressionBindingMid(DbGroupExpressionBinding binding)
      {
      }

      protected virtual void VisitGroupExpressionBindingPost(DbGroupExpressionBinding binding)
      {
      }

      protected virtual void VisitGroupExpressionBindingPre(DbGroupExpressionBinding binding)
      {
        if (binding == null) throw new ArgumentException("binding");
        VisitExpression(binding.Expression);
      }

      protected virtual void VisitLambdaFunctionPost(EdmFunction function, DbExpression body)
      {
      }

      protected virtual void VisitLambdaFunctionPre(EdmFunction function, DbExpression body)
      {
        if (function == null) throw new ArgumentException("function");
        if (body == null) throw new ArgumentException("body");
      }

      //internal virtual void VisitRelatedEntityReference(DbRelatedEntityRef relatedEntityRef)
      //{
      //  VisitExpression(relatedEntityRef.TargetEntityReference);
      //}

      //internal virtual void VisitRelatedEntityReferenceList(IList<DbRelatedEntityRef> relatedEntityReferences)
      //{
      //  for (int i = 0; i < relatedEntityReferences.Count; i++)
      //  {
      //    VisitRelatedEntityReference(relatedEntityReferences[i]);
      //  }
      //}

      protected virtual void VisitUnaryExpression(DbUnaryExpression expression)
      {
        if (expression == null) throw new ArgumentException("expression");
        VisitExpression(expression.Argument);
      }
      #endregion

      public override void Visit(DbAndExpression expression)
      {
        VisitBinary(expression, " AND ");
      }

      public override void Visit(DbOrExpression expression)
      {
        VisitBinary(expression, " OR ");
      }

      public override void Visit(DbComparisonExpression expression)
      {
        Debug.Assert(expression.ExpressionKind == DbExpressionKind.Equals,
            "only equals comparison expressions are produced in DML command trees in V1");

        VisitBinary(expression, " = ");

        RegisterMemberValue(expression.Left, expression.Right);
      }

      /// <summary>
      /// Call this method to register a property value pair so the translator "remembers"
      /// the values for members of the row being modified. These values can then be used
      /// to form a predicate for server-generation (based on the key of the row)
      /// </summary>
      /// <param name="propertyExpression">DbExpression containing the column reference (property expression).</param>
      /// <param name="value">DbExpression containing the value of the column.</param>
      internal void RegisterMemberValue(DbExpression propertyExpression, DbExpression value)
      {
        if (null != _memberValues)
        {
          // register the value for this property
          Debug.Assert(propertyExpression.ExpressionKind == DbExpressionKind.Property,
              "DML predicates and setters must be of the form property = value");

          // get name of left property 
          EdmMember property = ((DbPropertyExpression)propertyExpression).Property;

          // don't track null values
          if (value.ExpressionKind != DbExpressionKind.Null)
          {
            Debug.Assert(value.ExpressionKind == DbExpressionKind.Constant,
                "value must either constant or null");
            // retrieve the last parameter added (which describes the parameter)
            _memberValues[property] = _parameters[_parameters.Count - 1];
          }
        }
      }

      public override void Visit(DbIsNullExpression expression)
      {
        expression.Argument.Accept(this);
        _commandText.Append(" IS NULL");
      }

      public override void Visit(DbNotExpression expression)
      {
        _commandText.Append("NOT (");
        expression.Accept(this);
        _commandText.Append(")");
      }

      public override void Visit(DbConstantExpression expression)
      {
        SQLiteParameter parameter = CreateParameter(expression.Value, expression.ResultType);
        _commandText.Append(parameter.ParameterName);
      }

      public override void Visit(DbScanExpression expression)
      {
        string definingQuery = MetadataHelpers.TryGetValueForMetadataProperty<string>(expression.Target, "DefiningQuery");
        if (definingQuery != null)
        {
          throw new NotSupportedException(String.Format("Unable to update the EntitySet '{0}' because it has a DefiningQuery and no <{1}> element exists in the <ModificationFunctionMapping> element to support the current operation.", expression.Target.Name, _kind));
        }
        _commandText.Append(SqlGenerator.GetTargetTSql(expression.Target));
      }

      public override void Visit(DbPropertyExpression expression)
      {
        _commandText.Append(GenerateMemberTSql(expression.Property));
      }

      public override void Visit(DbNullExpression expression)
      {
        _commandText.Append("NULL");
      }

      public override void Visit(DbNewInstanceExpression expression)
      {
        // assumes all arguments are self-describing (no need to use aliases
        // because no renames are ever used in the projection)
        bool first = true;
        foreach (DbExpression argument in expression.Arguments)
        {
          if (first) { first = false; }
          else { _commandText.Append(", "); }
          argument.Accept(this);
        }
      }

      private void VisitBinary(DbBinaryExpression expression, string separator)
      {
        _commandText.Append("(");
        expression.Left.Accept(this);
        _commandText.Append(separator);
        expression.Right.Accept(this);
        _commandText.Append(")");
      }
    }
  }
}

//---------------------------------------------------------------------
// <copyright file="ISqlFragment.cs" company="Microsoft">
//      Portions of this file copyright (c) Microsoft Corporation
//      and are released under the Microsoft Pulic License.  See
//      http://archive.msdn.microsoft.com/EFSampleProvider/Project/License.aspx
//      or License.txt for details.
//      All rights reserved.
// </copyright>
//---------------------------------------------------------------------

namespace System.Data.SQLite
{
  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.IO;
  using System.Text;
  using System.Data.Metadata.Edm;
  using System.Data.Common.CommandTrees;

  /// <summary>
  /// Represents the sql fragment for any node in the query tree.
  /// </summary>
  /// <remarks>
  /// The nodes in a query tree produce various kinds of sql
  /// <list type="bullet">
  /// <item>A select statement.</item>
  /// <item>A reference to an extent. (symbol)</item>
  /// <item>A raw string.</item>
  /// </list>
  /// We have this interface to allow for a common return type for the methods
  /// in the expression visitor <see cref="DbExpressionVisitor{T}"/>
  /// 
  /// At the end of translation, the sql fragments are converted into real strings.
  /// </remarks>
  internal interface ISqlFragment
  {
    /// <summary>
    /// Write the string represented by this fragment into the stream.
    /// </summary>
    /// <param name="writer">The stream that collects the strings.</param>
    /// <param name="sqlGenerator">Context information used for renaming.
    /// The global lists are used to generated new names without collisions.</param>
    void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator);
  }
}

/********************************************************
 * ADO.NET 2.0 Data Provider for SQLite Version 3.X
 * Written by Robert Simpson (robert@blackcastlesoft.com)
 * 
 * Released to the public domain, use at your own risk!
 ********************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime;

namespace System.Data.SQLite
{
	internal abstract class InternalBase
	{
		// Methods
		[TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")]
		protected InternalBase()
		{
		}

		internal abstract void ToCompactString(StringBuilder builder);
		internal virtual string ToFullString()
		{
			StringBuilder builder = new StringBuilder();
			this.ToFullString(builder);
			return builder.ToString();
		}

		[TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")]
		internal virtual void ToFullString(StringBuilder builder)
		{
			this.ToCompactString(builder);
		}

		public override string ToString()
		{
			StringBuilder builder = new StringBuilder();
			this.ToCompactString(builder);
			return builder.ToString();
		}
	}
}

//---------------------------------------------------------------------
// <copyright file="JoinSymbol.cs" company="Microsoft">
//      Portions of this file copyright (c) Microsoft Corporation
//      and are released under the Microsoft Pulic License.  See
//      http://archive.msdn.microsoft.com/EFSampleProvider/Project/License.aspx
//      or License.txt for details.
//      All rights reserved.
// </copyright>
//---------------------------------------------------------------------

namespace System.Data.SQLite
{
  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.IO;
  using System.Text;
  using System.Data.Metadata.Edm;
  using System.Data.Common.CommandTrees;

  /// <summary>
  /// A Join symbol is a special kind of Symbol.
  /// It has to carry additional information
  /// <list type="bullet">
  /// <item>ColumnList for the list of columns in the select clause if this
  /// symbol represents a sql select statement.  This is set by <see cref="SqlGenerator.AddDefaultColumns"/>. </item>
  /// <item>ExtentList is the list of extents in the select clause.</item>
  /// <item>FlattenedExtentList - if the Join has multiple extents flattened at the 
  /// top level, we need this information to ensure that extent aliases are renamed
  /// correctly in <see cref="SqlSelectStatement.WriteSql"/></item>
  /// <item>NameToExtent has all the extents in ExtentList as a dictionary.
  /// This is used by <see cref="SqlGenerator.Visit(DbPropertyExpression)"/> to flatten
  /// record accesses.</item>
  /// <item>IsNestedJoin - is used to determine whether a JoinSymbol is an 
  /// ordinary join symbol, or one that has a corresponding SqlSelectStatement.</item>
  /// </list>
  /// 
  /// All the lists are set exactly once, and then used for lookups/enumerated.
  /// </summary>
  internal sealed class JoinSymbol : Symbol
  {
    private List<Symbol> columnList;
    internal List<Symbol> ColumnList
    {
      get
      {
        if (null == columnList)
        {
          columnList = new List<Symbol>();
        }
        return columnList;
      }
      set { columnList = value; }
    }

    private List<Symbol> extentList;
    internal List<Symbol> ExtentList
    {
      get { return extentList; }
    }

    private List<Symbol> flattenedExtentList;
    internal List<Symbol> FlattenedExtentList
    {
      get
      {
        if (null == flattenedExtentList)
        {
          flattenedExtentList = new List<Symbol>();
        }
        return flattenedExtentList;
      }
      set { flattenedExtentList = value; }
    }

    private Dictionary<string, Symbol> nameToExtent;
    internal Dictionary<string, Symbol> NameToExtent
    {
      get { return nameToExtent; }
    }

    private bool isNestedJoin;
    internal bool IsNestedJoin
    {
      get { return isNestedJoin; }
      set { isNestedJoin = value; }
    }

    public JoinSymbol(string name, TypeUsage type, List<Symbol> extents)
      : base(name, type)
    {
      extentList = new List<Symbol>(extents.Count);
      nameToExtent = new Dictionary<string, Symbol>(extents.Count, StringComparer.OrdinalIgnoreCase);
      foreach (Symbol symbol in extents)
      {
        this.nameToExtent[symbol.Name] = symbol;
        this.ExtentList.Add(symbol);
      }
    }
  }
}

/********************************************************
 * ADO.NET 2.0 Data Provider for SQLite Version 3.X
 * Written by Robert Simpson (robert@blackcastlesoft.com)
 * 
 * Released to the public domain, use at your own risk!
 ********************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.Runtime;
using System.Runtime.CompilerServices;
using System.Collections;

namespace System.Data.SQLite
{
	internal class KeyToListMap<TKey, TValue> : InternalBase
	{
		// Fields
		private Dictionary<TKey, List<TValue>> m_map;

		// Methods
		internal KeyToListMap(IEqualityComparer<TKey> comparer)
		{
			this.m_map = new Dictionary<TKey, List<TValue>>(comparer);
		}

		internal void Add(TKey key, TValue value)
		{
			List<TValue> list;
			if (!this.m_map.TryGetValue(key, out list))
			{
				list = new List<TValue>();
				this.m_map[key] = list;
			}
			list.Add(value);
		}

		internal void AddRange(TKey key, IEnumerable<TValue> values)
		{
			foreach (TValue local in values)
			{
				this.Add(key, local);
			}
		}

		internal bool ContainsKey(TKey key)
		{
			return this.m_map.ContainsKey(key);
		}

		internal IEnumerable<TValue> EnumerateValues(TKey key)
		{
			List<TValue> values;
			if (m_map.TryGetValue(key, out values))
			{
				foreach (TValue value in values) { yield return value; }
			}
		}

		internal ReadOnlyCollection<TValue> ListForKey(TKey key)
		{
			return new ReadOnlyCollection<TValue>(this.m_map[key]);
		}

		internal bool RemoveKey(TKey key)
		{
			return this.m_map.Remove(key);
		}

		internal override void ToCompactString(StringBuilder builder)
		{
			foreach (TKey local in this.Keys)
			{
				StringUtil.FormatStringBuilder(builder, "{0}", new object[] { local });
				builder.Append(": ");
				IEnumerable<TValue> list = this.ListForKey(local);
				StringUtil.ToSeparatedString(builder, list, ",", "null");
				builder.Append("; ");
			}
		}

		internal bool TryGetListForKey(TKey key, out ReadOnlyCollection<TValue> valueCollection)
		{
			List<TValue> list;
			valueCollection = null;
			if (this.m_map.TryGetValue(key, out list))
			{
				valueCollection = new ReadOnlyCollection<TValue>(list);
				return true;
			}
			return false;
		}

		// Properties
		internal IEnumerable<TValue> AllValues
		{
			get
			{
				foreach (TKey key in Keys)
				{
					foreach (TValue value in ListForKey(key))
					{
						yield return value;
					}
				}
			}
		}

		internal IEnumerable<TKey> Keys
		{
			get
			{
				return this.m_map.Keys;
			}
		}

		internal IEnumerable<KeyValuePair<TKey, List<TValue>>> KeyValuePairs
		{
			[TargetedPatchingOptOut("Performance critical to inline this type of method across NGen image boundaries")]
			get
			{
				return this.m_map;
			}
		}
	}
}

Microsoft Public License (Ms-PL)

This license governs use of the accompanying software. If you use the software, you accept this license. If you do not accept the license, do not use the software.

1. Definitions

The terms "reproduce," "reproduction," "derivative works," and "distribution" have the same meaning here as under U.S. copyright law.

A "contribution" is the original software, or any additions or changes to the software.

A "contributor" is any person that distributes its contribution under this license.

"Licensed patents" are a contributor's patent claims that read directly on its contribution.

2. Grant of Rights

(A) Copyright Grant- Subject to the terms of this license, including the license conditions and limitations in section 3, each contributor grants you a non-exclusive, worldwide, royalty-free copyright license to reproduce its contribution, prepare derivative works of its contribution, and distribute its contribution or any derivative works that you create.

(B) Patent Grant- Subject to the terms of this license, including the license conditions and limitations in section 3, each contributor grants you a non-exclusive, worldwide, royalty-free license under its licensed patents to make, have made, use, sell, offer for sale, import, and/or otherwise dispose of its contribution in the software or derivative works of the contribution in the software.

3. Conditions and Limitations

(A) No Trademark License- This license does not grant you rights to use any contributors' name, logo, or trademarks.

(B) If you bring a patent claim against any contributor over patents that you claim are infringed by the software, your patent license from such contributor to the software ends automatically.

(C) If you distribute any portion of the software, you must retain all copyright, patent, trademark, and attribution notices that are present in the software.

(D) If you distribute any portion of the software in source code form, you may do so only under this license by including a complete copy of this license with your distribution. If you distribute any portion of the software in compiled or object code form, you may only do so under a license that complies with this license.

(E) The software is licensed "as-is." You bear the risk of using it. The contributors give no express warranties, guarantees or conditions. You may have additional consumer rights under your local laws which this license cannot change. To the extent permitted under your local laws, the contributors exclude the implied warranties of merchantability, fitness for a particular purpose and non-infringement. 

//---------------------------------------------------------------------
// <copyright file="MetadataHelpers.cs" company="Microsoft">
//      Portions of this file copyright (c) Microsoft Corporation
//      and are released under the Microsoft Pulic License.  See
//      http://archive.msdn.microsoft.com/EFSampleProvider/Project/License.aspx
//      or License.txt for details.
//      All rights reserved.
// </copyright>
//---------------------------------------------------------------------

namespace System.Data.SQLite
{
  using System;
  using System.Data;
  using System.Data.Common;
  using System.Collections.Generic;
  using System.Data.Metadata.Edm;
  using System.Diagnostics;

  /// <summary>
  /// A set of static helpers for type metadata
  /// </summary>
  static class MetadataHelpers
  {
    #region Type Helpers

    /// <summary>
    /// Cast the EdmType of the given type usage to the given TEdmType
    /// </summary>
    /// <typeparam name="TEdmType"></typeparam>
    /// <param name="typeUsage"></param>
    /// <returns></returns>
    internal static TEdmType GetEdmType<TEdmType>(TypeUsage typeUsage)
        where TEdmType : EdmType
    {
      return (TEdmType)typeUsage.EdmType;
    }

    /// <summary>
    /// Gets the TypeUsage of the elment if the given type is a collection type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static TypeUsage GetElementTypeUsage(TypeUsage type)
    {
      if (MetadataHelpers.IsCollectionType(type))
      {
        return ((CollectionType)type.EdmType).TypeUsage;
      }
      return null;
    }

    /// <summary>
    /// Retrieves the properties of in the EdmType underlying the input type usage, 
    ///  if that EdmType is a structured type (EntityType, RowType). 
    /// </summary>
    /// <param name="typeUsage"></param>
    /// <returns></returns>
    internal static IList<EdmProperty> GetProperties(TypeUsage typeUsage)
    {
      return MetadataHelpers.GetProperties(typeUsage.EdmType);
    }

    /// <summary>
    /// Retrieves the properties of the given EdmType, if it is
    ///  a structured type (EntityType, RowType). 
    /// </summary>
    /// <param name="edmType"></param>
    /// <returns></returns>
    internal static IList<EdmProperty> GetProperties(EdmType edmType)
    {
      switch (edmType.BuiltInTypeKind)
      {
        case BuiltInTypeKind.ComplexType:
          return ((ComplexType)edmType).Properties;
        case BuiltInTypeKind.EntityType:
          return ((EntityType)edmType).Properties;
        case BuiltInTypeKind.RowType:
          return ((RowType)edmType).Properties;
        default:
          return new List<EdmProperty>();
      }
    }

    /// <summary>
    /// Is the given type usage over a collection type
    /// </summary>
    /// <param name="typeUsage"></param>
    /// <returns></returns>
    internal static bool IsCollectionType(TypeUsage typeUsage)
    {
      return MetadataHelpers.IsCollectionType(typeUsage.EdmType);
    }

    /// <summary>
    /// Is the given type a collection type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static bool IsCollectionType(EdmType type)
    {
      return (BuiltInTypeKind.CollectionType == type.BuiltInTypeKind);
    }

    /// <summary>
    /// Is the given type usage over a primitive type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static bool IsPrimitiveType(TypeUsage type)
    {
      return MetadataHelpers.IsPrimitiveType(type.EdmType);
    }

    /// <summary>
    /// Is the given type a primitive type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static bool IsPrimitiveType(EdmType type)
    {
      return (BuiltInTypeKind.PrimitiveType == type.BuiltInTypeKind);
    }

    /// <summary>
    /// Is the given type usage over a row type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static bool IsRowType(TypeUsage type)
    {
      return MetadataHelpers.IsRowType(type.EdmType);
    }

    /// <summary>
    /// Is the given type a row type
    /// </summary>
    /// <param name="type"></param>
    /// <returns></returns>
    internal static bool IsRowType(EdmType type)
    {
      return (BuiltInTypeKind.RowType == type.BuiltInTypeKind);
    }

    /// <summary>
    /// Gets the type of the given type usage if it is a primitive type
    /// </summary>
    /// <param name="type"></param>
    /// <param name="typeKind"></param>
    /// <returns></returns>
    internal static bool TryGetPrimitiveTypeKind(TypeUsage type, out PrimitiveTypeKind typeKind)
    {
      if (type != null && type.EdmType != null && type.EdmType.BuiltInTypeKind == BuiltInTypeKind.PrimitiveType)
      {
        typeKind = ((PrimitiveType)type.EdmType).PrimitiveTypeKind;
        return true;
      }

      typeKind = default(PrimitiveTypeKind);
      return false;
    }

    internal static PrimitiveTypeKind GetPrimitiveTypeKind(TypeUsage type)
    {
      PrimitiveTypeKind returnValue;
      if (!MetadataHelpers.TryGetPrimitiveTypeKind(type, out returnValue))
      {
        Debug.Assert(false, "Cannot create parameter of non-primitive type");
        throw new NotSupportedException("Cannot create parameter of non-primitive type");
      }
      return returnValue;
    }

    /// <summary>
    /// Gets the value for the metadata property with the given name
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="item"></param>
    /// <param name="propertyName"></param>
    /// <returns></returns>
    internal static T TryGetValueForMetadataProperty<T>(MetadataItem item, string propertyName)
    {
      MetadataProperty property;
      if (!item.MetadataProperties.TryGetValue(propertyName, true, out property))
      {
        return default(T);
      }

      return (T)property.Value;
    }

    internal static bool IsPrimitiveType(TypeUsage type, PrimitiveTypeKind primitiveType)
    {
      PrimitiveTypeKind typeKind;
      if (TryGetPrimitiveTypeKind(type, out typeKind))
      {
        return (typeKind == primitiveType);
      }
      return false;
    }

    internal static DbType GetDbType(PrimitiveTypeKind primitiveType)
    {
      switch (primitiveType)
      {
        case PrimitiveTypeKind.Binary: return DbType.Binary;
        case PrimitiveTypeKind.Boolean: return DbType.Boolean;
        case PrimitiveTypeKind.Byte: return DbType.Byte;
        case PrimitiveTypeKind.DateTime: return DbType.DateTime;
        case PrimitiveTypeKind.Decimal: return DbType.Decimal;
        case PrimitiveTypeKind.Double: return DbType.Double;
        case PrimitiveTypeKind.Single: return DbType.Single;
        case PrimitiveTypeKind.Guid: return DbType.Guid;
        case PrimitiveTypeKind.Int16: return DbType.Int16;
        case PrimitiveTypeKind.Int32: return DbType.Int32;
        case PrimitiveTypeKind.Int64: return DbType.Int64;
        //case PrimitiveTypeKind.Money: return DbType.Decimal;
        case PrimitiveTypeKind.SByte: return DbType.SByte;
        case PrimitiveTypeKind.String: return DbType.String;
        //case PrimitiveTypeKind.UInt16: return DbType.UInt16;
        //case PrimitiveTypeKind.UInt32: return DbType.UInt32;
        //case PrimitiveTypeKind.UInt64: return DbType.UInt64;
        //case PrimitiveTypeKind.Xml: return DbType.Xml;
        default:
          Debug.Fail("unknown PrimitiveTypeKind" + primitiveType.ToString());
          throw new InvalidOperationException(string.Format("Unknown PrimitiveTypeKind {0}", primitiveType));
      }
    }

    #endregion

    #region Facet Support
    internal static readonly int UnicodeStringMaxMaxLength = Int32.MaxValue;
    internal static readonly int AsciiStringMaxMaxLength = Int32.MaxValue;
    internal static readonly int BinaryMaxMaxLength = Int32.MaxValue;

    #region Facet Names
    /// <summary>
    /// Name of the MaxLength Facet
    /// </summary>
    public static readonly string MaxLengthFacetName = "MaxLength";

    /// <summary>
    /// Name of the Unicode Facet
    /// </summary>
    public static readonly string UnicodeFacetName = "Unicode";

    /// <summary>
    /// Name of the FixedLength Facet
    /// </summary>
    public static readonly string FixedLengthFacetName = "FixedLength";

    /// <summary>
    /// Name of the PreserveSeconds Facet
    /// </summary>
    public static readonly string PreserveSecondsFacetName = "PreserveSeconds";

    /// <summary>
    /// Name of the Precision Facet
    /// </summary>
    public static readonly string PrecisionFacetName = "Precision";

    /// <summary>
    /// Name of the Scale Facet
    /// </summary>
    public static readonly string ScaleFacetName = "Scale";

    /// <summary>
    /// Name of the DefaultValue Facet
    /// </summary>
    public static readonly string DefaultValueFacetName = "DefaultValue";

    /// <summary>
    /// Name of the Nullable Facet
    /// </summary>
    internal const string NullableFacetName = "Nullable";
    #endregion

    #region Facet Retreival Helpers

    /// <summary>
    /// Get the value specified on the given type usage for the given facet name.
    /// If the faces does not have a value specifid or that value is null returns
    /// the default value for that facet.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="type"></param>
    /// <param name="facetName"></param>
    /// <returns></returns>
    /// <summary>
    /// Get the value specified on the given type usage for the given facet name.
    /// If the faces does not have a value specifid or that value is null returns
    /// the default value for that facet.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="type"></param>
    /// <param name="facetName"></param>
    /// <returns></returns>
    internal static T GetFacetValueOrDefault<T>(TypeUsage type, string facetName, T defaultValue)
    {
      //Get the value for the facet, if any
      Facet facet;
      if (type.Facets.TryGetValue(facetName, false, out facet) && facet.Value != null && !facet.IsUnbounded)
      {
        return (T)facet.Value;
      }
      else
      {
        return defaultValue;
      }
    }

    internal static bool IsFacetValueConstant(TypeUsage type, string facetName)
    {
      return MetadataHelpers.GetFacet(((PrimitiveType)type.EdmType).FacetDescriptions, facetName).IsConstant;
    }

    private static FacetDescription GetFacet(IEnumerable<FacetDescription> facetCollection, string facetName)
    {
      foreach (FacetDescription facetDescription in facetCollection)
      {
        if (facetDescription.FacetName == facetName)
        {
          return facetDescription;
        }
      }

      return null;
    }

    /// <summary>
    /// Given a facet name and an EdmType, tries to get that facet's description.
    /// </summary>
    /// <param name="edmType"></param>
    /// <param name="facetName"></param>
    /// <param name="facetDescription"></param>
    /// <returns></returns>
    internal static bool TryGetTypeFacetDescriptionByName(EdmType edmType, string facetName, out FacetDescription facetDescription)
    {
      facetDescription = null;
      if (MetadataHelpers.IsPrimitiveType(edmType))
      {
        PrimitiveType primitiveType = (PrimitiveType)edmType;
        foreach (FacetDescription fd in primitiveType.FacetDescriptions)
        {
          if (facetName.Equals(fd.FacetName, StringComparison.OrdinalIgnoreCase))
          {
            facetDescription = fd;
            return true;
          }
        }
      }
      return false;
    }

    internal static bool IsNullable(TypeUsage type)
    {
      Facet nullableFacet;
      if (type.Facets.TryGetValue(NullableFacetName, false, out nullableFacet))
      {
        return (bool)nullableFacet.Value;
      }
      return false;
    }

    internal static bool TryGetMaxLength(TypeUsage type, out int maxLength)
    {
      if (!IsPrimitiveType(type, PrimitiveTypeKind.String) &&
          !IsPrimitiveType(type, PrimitiveTypeKind.Binary))
      {
        maxLength = 0;
        return false;
      }

      // Binary and String FixedLength facets share the same name
      return TryGetIntFacetValue(type, MaxLengthFacetName, out maxLength);
    }

    internal static bool TryGetIntFacetValue(TypeUsage type, string facetName, out int intValue)
    {
      intValue = 0;
      Facet intFacet;

      if (type.Facets.TryGetValue(facetName, false, out intFacet) && intFacet.Value != null && !intFacet.IsUnbounded)
      {
        intValue = (int)intFacet.Value;
        return true;
      }

      return false;
    }

    internal static bool TryGetIsFixedLength(TypeUsage type, out bool isFixedLength)
    {
      if (!IsPrimitiveType(type, PrimitiveTypeKind.String) &&
          !IsPrimitiveType(type, PrimitiveTypeKind.Binary))
      {
        isFixedLength = false;
        return false;
      }

      // Binary and String MaxLength facets share the same name
      return TryGetBooleanFacetValue(type, FixedLengthFacetName, out isFixedLength);
    }

    internal static bool TryGetBooleanFacetValue(TypeUsage type, string facetName, out bool boolValue)
    {
      boolValue = false;
      Facet boolFacet;
      if (type.Facets.TryGetValue(facetName, false, out boolFacet) && boolFacet.Value != null)
      {
        boolValue = (bool)boolFacet.Value;
        return true;
      }

      return false;
    }

    internal static bool TryGetIsUnicode(TypeUsage type, out bool isUnicode)
    {
      if (!IsPrimitiveType(type, PrimitiveTypeKind.String))
      {
        isUnicode = false;
        return false;
      }

      return TryGetBooleanFacetValue(type, UnicodeFacetName, out isUnicode);
    }

    #endregion

    #endregion

    internal static bool IsCanonicalFunction(EdmFunction function)
    {
      return (function.NamespaceName == "Edm");
    }

    internal static bool IsStoreFunction(EdmFunction function)
    {
      return !IsCanonicalFunction(function);
    }

    // Returns ParameterDirection corresponding to given ParameterMode
    internal static ParameterDirection ParameterModeToParameterDirection(ParameterMode mode)
    {
      switch (mode)
      {
        case ParameterMode.In:
          return ParameterDirection.Input;

        case ParameterMode.InOut:
          return ParameterDirection.InputOutput;

        case ParameterMode.Out:
          return ParameterDirection.Output;

        case ParameterMode.ReturnValue:
          return ParameterDirection.ReturnValue;

        default:
          Debug.Fail("unrecognized mode " + mode.ToString());
          return default(ParameterDirection);
      }
    }
  }
}

//---------------------------------------------------------------------
// <copyright file="SqlBuilder.cs" company="Microsoft">
//      Portions of this file copyright (c) Microsoft Corporation
//      and are released under the Microsoft Pulic License.  See
//      http://archive.msdn.microsoft.com/EFSampleProvider/Project/License.aspx
//      or License.txt for details.
//      All rights reserved.
// </copyright>
//---------------------------------------------------------------------

namespace System.Data.SQLite
{
  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.IO;
  using System.Text;
  using System.Data.Metadata.Edm;
  using System.Data.Common.CommandTrees;

  /// <summary>
  /// This class is like StringBuilder.  While traversing the tree for the first time, 
  /// we do not know all the strings that need to be appended e.g. things that need to be
  /// renamed, nested select statements etc.  So, we use a builder that can collect
  /// all kinds of sql fragments.
  /// </summary>
  internal sealed class SqlBuilder : ISqlFragment
  {
    private List<object> _sqlFragments;
    private List<object> sqlFragments
    {
      get
      {
        if (null == _sqlFragments)
        {
          _sqlFragments = new List<object>();
        }
        return _sqlFragments;
      }
    }


    /// <summary>
    /// Add an object to the list - we do not verify that it is a proper sql fragment
    /// since this is an internal method.
    /// </summary>
    /// <param name="s"></param>
    public void Append(object s)
    {
      Debug.Assert(s != null);
      sqlFragments.Add(s);
    }

    /// <summary>
    /// This is to pretty print the SQL.  The writer <see cref="SqlWriter.Write"/>
    /// needs to know about new lines so that it can add the right amount of 
    /// indentation at the beginning of lines.
    /// </summary>
    public void AppendLine()
    {
      sqlFragments.Add("\r\n");
    }

    /// <summary>
    /// Whether the builder is empty.  This is used by the <see cref="SqlGenerator.Visit(DbProjectExpression)"/>
    /// to determine whether a sql statement can be reused.
    /// </summary>
    public bool IsEmpty
    {
      get { return ((null == _sqlFragments) || (0 == _sqlFragments.Count)); }
    }

    #region ISqlFragment Members

    /// <summary>
    /// We delegate the writing of the fragment to the appropriate type.
    /// </summary>
    /// <param name="writer"></param>
    /// <param name="sqlGenerator"></param>
    public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator)
    {
      if (null != _sqlFragments)
      {
        foreach (object o in _sqlFragments)
        {
          string str = (o as String);
          if (null != str)
          {
            writer.Write(str);
          }
          else
          {
            ISqlFragment sqlFragment = (o as ISqlFragment);
            if (null != sqlFragment)
            {
              sqlFragment.WriteSql(writer, sqlGenerator);
            }
            else
            {
              throw new InvalidOperationException();
            }
          }
        }
      }
    }

    #endregion
  }
}