System.Data.SQLite

__declspec(dllexport) const char * __stdcall sqlite3_errmsg_interop(sqlite3 *db, int *plen)
{
  const char *pval = sqlite3_errmsg(db);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_errmsg16_interop(sqlite3 *db)
__declspec(dllexport) const void * __stdcall sqlite3_errmsg16_interop(sqlite3 *db, int *plen)
{
  return sqlite3_errmsg16(db);
  const void *pval = sqlite3_errmsg16(db);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t): 0;
  return pval;
}

__declspec(dllexport) int __stdcall sqlite3_prepare_interop(sqlite3 *db, const char *sql, int nbytes, sqlite3_stmt **ppstmt, const char **pztail, int *plen)
{
  int n = sqlite3_prepare(db, sql, nbytes, ppstmt, pztail);
  *plen = (*pztail != 0) ? strlen(*pztail) : 0;
  return n;
}

__declspec(dllexport) int __stdcall sqlite3_prepare16_interop(sqlite3 *db, const void *sql, int nbytes, sqlite3_stmt **ppstmt, const void **pztail)
__declspec(dllexport) int __stdcall sqlite3_prepare16_interop(sqlite3 *db, const void *sql, int nbytes, sqlite3_stmt **ppstmt, const void **pztail, int *plen)
{
  return sqlite3_prepare16(db, sql, nbytes, ppstmt, pztail);
  int n = sqlite3_prepare16(db, sql, nbytes, ppstmt, pztail);
  *plen = (*pztail != 0) ? wcslen((wchar_t *)*pztail) * sizeof(wchar_t) : 0;
  return n;
}

__declspec(dllexport) int __stdcall sqlite3_bind_blob_interop(sqlite3_stmt *stmt, int iCol, const void *pv, int n, void(*cb)(void*))
{
  return sqlite3_bind_blob(stmt, iCol, pv, n, cb);
}

__declspec(dllexport) const char * __stdcall sqlite3_column_name_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const char *pval = sqlite3_column_name(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_name16_interop(sqlite3_stmt *stmt, int iCol)
__declspec(dllexport) const void * __stdcall sqlite3_column_name16_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  return sqlite3_column_name16(stmt, iCol);
  const void *pval = sqlite3_column_name16(stmt, iCol);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t) : 0;
  return pval;
}

__declspec(dllexport) const char * __stdcall sqlite3_column_decltype_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const char *pval = sqlite3_column_decltype(stmt, iCol);
  *plen = (pval != 0) ? strlen(pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_decltype16_interop(sqlite3_stmt *stmt, int iCol)
__declspec(dllexport) const void * __stdcall sqlite3_column_decltype16_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  return sqlite3_column_decltype16(stmt, iCol);
  const void *pval = sqlite3_column_decltype16(stmt, iCol);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t) : 0;
  return pval;
}

__declspec(dllexport) int __stdcall sqlite3_step_interop(sqlite3_stmt *stmt)
{
  return sqlite3_step(stmt);
}

__declspec(dllexport) const unsigned char * __stdcall sqlite3_column_text_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  const unsigned char *pval = sqlite3_column_text(stmt, iCol);
  *plen = (pval != 0) ? strlen((char *)pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_column_text16_interop(sqlite3_stmt *stmt, int iCol)
__declspec(dllexport) const void * __stdcall sqlite3_column_text16_interop(sqlite3_stmt *stmt, int iCol, int *plen)
{
  return sqlite3_column_text16(stmt, iCol);
  const void *pval = sqlite3_column_text16(stmt, iCol);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t): 0;
  return pval;
}

__declspec(dllexport) int __stdcall sqlite3_column_type_interop(sqlite3_stmt *stmt, int iCol)
{
  return sqlite3_column_type(stmt, iCol);
}

__declspec(dllexport) const unsigned char * __stdcall sqlite3_value_text_interop(sqlite3_value *val, int *plen)
{
  const unsigned char *pval = sqlite3_value_text(val);
  *plen = (pval != 0) ? strlen((char *)pval) : 0;
  return pval;
}

__declspec(dllexport) const void * __stdcall sqlite3_value_text16_interop(sqlite3_value *val)
__declspec(dllexport) const void * __stdcall sqlite3_value_text16_interop(sqlite3_value *val, int *plen)
{
  return sqlite3_value_text16(val);
  const void *pval = sqlite3_value_text16(val);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t) : 0;
  return pval;
}

__declspec(dllexport) int __stdcall sqlite3_value_type_interop(sqlite3_value *val)
{
  return sqlite3_value_type(val);
}

    /// <returns>A .NET string</returns>
    public override string ToString(IntPtr b, int nbytelen)
    {
      if (nbytelen == 0) return "";
      return Marshal.PtrToStringUni(b, nbytelen / 2);
    }

    /// <summary>
    /// Another custom string marshaling function
    internal override string Version
    /// </summary>
    /// <param name="b">A pointer to a zero-terminated UTF-16 string</param>
    /// <returns>A .NET string</returns>
    {
      get
    internal static string ToString(IntPtr b)
    {
      if (b == IntPtr.Zero) return "";
      return Marshal.PtrToStringUni(b);
      {
        int len;
        return base.ToString(UnsafeNativeMethods.sqlite3_libversion_interop(out len), len);
      }
    }

    internal override void Open(string strFilename)
    {
      if (_sql != 0) return;
      int n = UnsafeNativeMethods.sqlite3_open16_interop(strFilename, out _sql);
      if (n > 0) throw new SQLiteException(n, SQLiteLastError());

      _functionsArray = SQLiteFunction.BindFunctions(this);
    }

    internal override string SQLiteLastError()
    {
      int len;
      return ToString(UnsafeNativeMethods.sqlite3_errmsg16_interop(_sql));
      return ToString(UnsafeNativeMethods.sqlite3_errmsg16_interop(_sql, out len), len);
    }

    internal override SQLiteStatement Prepare(string strSql, ref int nParamStart, out string strRemain)
    {
      int stmt;
      IntPtr ptr;
      int len;

      int n = UnsafeNativeMethods.sqlite3_prepare16_interop(_sql, strSql, strSql.Length, out stmt, out ptr);
      int n = UnsafeNativeMethods.sqlite3_prepare16_interop(_sql, strSql, strSql.Length, out stmt, out ptr, out len);
      if (n > 0) throw new SQLiteException(n, SQLiteLastError());

      strRemain = ToString(ptr);
      strRemain = ToString(ptr, len);

      SQLiteStatement cmd = new SQLiteStatement(this, stmt, strSql.Substring(0, strSql.Length - strRemain.Length), ref nParamStart);

      return cmd;
    }

    internal override void Bind_DateTime(SQLiteStatement stmt, int index, DateTime dt)
    {
      Bind_Text(stmt, index, ToString(dt));
    }

    internal override string Bind_ParamName(SQLiteStatement stmt, int index)
    {
      int len;
      return base.ToString(UnsafeNativeMethods.sqlite3_bind_parameter_name_interop(stmt._sqlite_stmt, index, out len), len);
    }

    internal override void Bind_Text(SQLiteStatement stmt, int index, string value)
    {
      int n = UnsafeNativeMethods.sqlite3_bind_text16_interop(stmt._sqlite_stmt, index, value, value.Length * 2, -1);
      if (n > 0) throw new SQLiteException(n, SQLiteLastError());
    }

    internal override string ColumnName(SQLiteStatement stmt, int index)
    {
      int len;
      return ToString(UnsafeNativeMethods.sqlite3_column_name16_interop(stmt._sqlite_stmt, index));
      return ToString(UnsafeNativeMethods.sqlite3_column_name16_interop(stmt._sqlite_stmt, index, out len), len);
    }

    internal override DateTime GetDateTime(SQLiteStatement stmt, int index)
    {
      return ToDateTime(GetText(stmt, index));
    }
    internal override string GetText(SQLiteStatement stmt, int index)
    {
      int len;
      return ToString(UnsafeNativeMethods.sqlite3_column_text16_interop(stmt._sqlite_stmt, index));
      return ToString(UnsafeNativeMethods.sqlite3_column_text16_interop(stmt._sqlite_stmt, index, out len), len);
    }

    internal override string ColumnType(SQLiteStatement stmt, int index, out TypeAffinity nAffinity)
    {
      nAffinity = TypeAffinity.None;

      IntPtr p = UnsafeNativeMethods.sqlite3_column_decltype16_interop(stmt._sqlite_stmt, index);
      if (p != IntPtr.Zero) return ToString(p);
      
      int len;
      IntPtr p = UnsafeNativeMethods.sqlite3_column_decltype16_interop(stmt._sqlite_stmt, index, out len);

      if (p != IntPtr.Zero) return ToString(p, len);
      else
      {
        nAffinity = UnsafeNativeMethods.sqlite3_column_type_interop(stmt._sqlite_stmt, index);
        switch (nAffinity)
        {
          case TypeAffinity.Int64:
            return "BIGINT";

      if (n > 0) throw new SQLiteException(n, SQLiteLastError());

      return nCookie;
    }

    internal override string GetParamValueText(int ptr)
    {
      int len;
      return ToString(UnsafeNativeMethods.sqlite3_value_text16_interop(ptr));
      return ToString(UnsafeNativeMethods.sqlite3_value_text16_interop(ptr, out len), len);
    }

    internal override void ReturnError(int context, string value)
    {
      UnsafeNativeMethods.sqlite3_result_error16_interop(context, value, value.Length);
    }

    internal override void ReturnText(int context, string value)
    {
      UnsafeNativeMethods.sqlite3_result_text16_interop(context, value, value.Length, -1);
    }
  }
}

        case DateTimeFormat.Ticks:
          return new DateTime(Convert.ToInt64(dateText, System.Globalization.CultureInfo.InvariantCulture));
        default:
          return DateTime.ParseExact(dateText, _datetimeFormats, System.Globalization.DateTimeFormatInfo.InvariantInfo, System.Globalization.DateTimeStyles.None);
      }
    }

    ///// <summary>
    ///// Attempt to convert the specified string to a datetime value.
    ///// </summary>
    ///// <param name="strSrc">The string to parse into a datetime</param>
    ///// <param name="result">If successful, a valid datetime structure</param>
    ///// <returns>Returns true if the string was a valid ISO8601 datetime, false otherwise.</returns>
    //public bool TryToDateTime(string strSrc, out DateTime result)
    //{
    //  switch (_datetimeFormat)
    //  {
    //    case DateTimeFormat.ISO8601:
    //      return DateTime.TryParseExact(strSrc, _datetimeFormats, System.Globalization.DateTimeFormatInfo.InvariantInfo, System.Globalization.DateTimeStyles.None, out result);
    //    case DateTimeFormat.Ticks:
    //      {
    //        long n;
    //        if (long.TryParse(strSrc, out n) == true)
    //        {
    //          result = new DateTime(n);
    //          return true;
    //        }
    //      }
    //      break;
    //  }

    //  result = DateTime.Now;
    //  return false;
    //}

    /// <summary>
    /// Converts a DateTime to a string value, using the current DateTimeFormat specified for the connection when it was opened.
    /// </summary>
    /// <param name="dateValue">The DateTime value to convert</param>
    /// <returns>Either a string consisting of the tick count for DateTimeFormat.Ticks, or a date/time in ISO8601 format.</returns>
    public string ToString(DateTime dateValue)
    {

    /// <param name="t">The SQLiteType to convert</param>
    /// <returns>Returns a .NET Type object</returns>
    internal static Type SQLiteTypeToType(SQLiteType t)
    {
      if (t.Type != DbType.Object)
        return SQLiteConvert.DbTypeToType(t.Type);

      switch (t.Affinity)
      {
        case TypeAffinity.Null:
          return typeof(DBNull);
      return _typeaffinities[(int)t.Affinity];
    }

    static Type[] _typeaffinities = {
      null,
        case TypeAffinity.Int64:
          return typeof(Int64);
      typeof(Int64),
        case TypeAffinity.Double:
          return typeof(Double);
        case TypeAffinity.Blob:
          return typeof(byte[]);
        default:
          return typeof(string);
      }
      typeof(Double),
      typeof(string),
      typeof(byte[]),
      typeof(DBNull),
      null,
      null,
      null,
      null,
      typeof(DateTime),
    };
    }

    /// <summary>
    /// For a given intrinsic type, return a DbType
    /// </summary>
    /// <param name="typ">The native type to convert</param>
    /// <returns>The corresponding (closest match) DbType</returns>
    internal static DbType TypeToDbType(Type typ)
    {
      switch (Type.GetTypeCode(typ))
      TypeCode tc = Type.GetTypeCode(typ);
      if (tc == TypeCode.Object)
      {
        case TypeCode.Int16:
          return DbType.Int16;
        case TypeCode.Int32:
          return DbType.Int32;
        case TypeCode.Int64:
          return DbType.Int64;
        case TypeCode.UInt16:
          return DbType.UInt16;
        case TypeCode.UInt32:
          return DbType.UInt32;
        case TypeCode.UInt64:
          return DbType.UInt64;
        case TypeCode.Double:
          return DbType.Double;
        if (typ == typeof(byte[])) return DbType.Binary;
        if (typ == typeof(Guid)) return DbType.Guid;
        return DbType.String;
      }
      return _typetodbtype[(int)tc];
    }

    private static DbType[] _typetodbtype = {
      DbType.Object,
      DbType.Binary,
      DbType.Object,
      DbType.Boolean,
      DbType.SByte,
      DbType.SByte,
      DbType.Byte,
      DbType.Int16, // 7
      DbType.UInt16,
      DbType.Int32,
      DbType.UInt32,
      DbType.Int64, // 11
      DbType.UInt64,
      DbType.Single,
      DbType.Double,
        case TypeCode.Single:
          return DbType.Single;
        case TypeCode.Decimal:
          return DbType.Decimal;
      DbType.Decimal,
        case TypeCode.Boolean:
          return DbType.Boolean;
        case TypeCode.SByte:
        case TypeCode.Char:
          return DbType.SByte;
        case TypeCode.DateTime:
          return DbType.DateTime;
      DbType.DateTime,
        case TypeCode.String:
          return DbType.String;
        case TypeCode.Object:
      DbType.Object,
          if (typ == typeof(byte[])) return DbType.Binary;
          if (typ == typeof(Guid)) return DbType.Guid;
          return DbType.String;
      }
      DbType.String,
    };

      return DbType.String;
    }

    /// <summary>
    /// Convert a DbType to a Type
    /// </summary>
    /// <param name="typ">The DbType to convert from</param>
    /// <returns>The closest-match .NET type</returns>
    internal static Type DbTypeToType(DbType typ)
    {
      switch (typ)
      {
        case DbType.Binary:
          return typeof(byte[]);
      return _dbtypeToType[(int)typ];
    }

    private static Type[] _dbtypeToType = {
      typeof(string),   // 0
        case DbType.Boolean:
          return typeof(bool);
      typeof(byte[]),   // 1
        case DbType.Byte:
          return typeof(byte);
        case DbType.Currency:
      typeof(byte),     // 2
      typeof(bool),     // 3
        case DbType.Decimal:
          return typeof(decimal);
        case DbType.DateTime:
          return typeof(DateTime);
        case DbType.Double:
          return typeof(double);
      typeof(decimal),  // 4
      typeof(DateTime), // 5
      typeof(DateTime), // 6
      typeof(decimal),  // 7
      typeof(double),   // 8
        case DbType.Guid:
          return typeof(Guid);
      typeof(Guid),     // 9
        case DbType.Int16:
        case DbType.UInt16:
          return typeof(Int16);
      typeof(Int16),
        case DbType.Int32:
        case DbType.UInt32:
          return typeof(Int32);
        case DbType.Int64:
        case DbType.UInt64:
          return typeof(Int64);
        case DbType.String:
          return typeof(string);
        case DbType.SByte:
          return typeof(char);
        case DbType.Single:
          return typeof(float);
      typeof(Int32),
      typeof(Int64),
      typeof(object),
      typeof(sbyte),
      typeof(float),
      typeof(string),
      typeof(DateTime),
      typeof(UInt16),
      typeof(UInt32),
      typeof(UInt64),
      typeof(double),
      }
      return typeof(string);
    }
      typeof(string),
      typeof(string),
      typeof(string),
      typeof(string),   // 25 (Xml)
    };

    /// <summary>
    /// For a given type, return the closest-match SQLite TypeAffinity, which only understands a very limited subset of types.
    /// </summary>
    /// <param name="typ">The type to evaluate</param>
    /// <returns>The SQLite type affinity for that type.</returns>
    internal static TypeAffinity TypeToAffinity(Type typ)
    {
      switch (Type.GetTypeCode(typ))
      TypeCode tc = Type.GetTypeCode(typ);
      if (tc == TypeCode.Object)
      {
        case TypeCode.DBNull:
          return TypeAffinity.Null;
        case TypeCode.String:
        if (typ == typeof(byte[]))
          return TypeAffinity.Blob;
        else
          return TypeAffinity.Text;
      }
      return _typecodeAffinities[(int)tc];
    }
        case TypeCode.DateTime:
          return TypeAffinity.DateTime;
        case TypeCode.Int16:
        case TypeCode.Int32:
        case TypeCode.Int64:
        case TypeCode.UInt16:
        case TypeCode.UInt32:
        case TypeCode.UInt64:
        case TypeCode.Char:
        case TypeCode.SByte:
        case TypeCode.Byte:

    private static TypeAffinity[] _typecodeAffinities = {
      TypeAffinity.Null,
      TypeAffinity.Blob,
      TypeAffinity.Null,
      TypeAffinity.Int64,
      TypeAffinity.Int64,
      TypeAffinity.Int64,
      TypeAffinity.Int64,
      TypeAffinity.Int64, // 7
      TypeAffinity.Int64,
      TypeAffinity.Int64,
        case TypeCode.Boolean:
          return TypeAffinity.Int64;
        case TypeCode.Double:
        case TypeCode.Single:
        case TypeCode.Decimal:
          return TypeAffinity.Double;
        case TypeCode.Object:
          if (typ == typeof(byte[])) return TypeAffinity.Blob;
          else return TypeAffinity.Text;
      TypeAffinity.Int64,
      TypeAffinity.Int64, // 11
      TypeAffinity.Int64,
      TypeAffinity.Double,
      TypeAffinity.Double,
      TypeAffinity.Double,
      TypeAffinity.DateTime,
      TypeAffinity.Null,
      }
      return TypeAffinity.Text;
    }
      TypeAffinity.Text,
    };

    /// <summary>
    /// For a given type name, return a closest-match .NET type
    /// </summary>
    /// <param name="Name">The name of the type to match</param>
    /// <returns>The .NET DBType the text evaluates to.</returns>
    internal static DbType TypeNameToDbType(string Name)

    [DllImport(SQLITE_DLL)]
    internal static extern int sqlite3_aggregate_context_interop(int context, int nBytes);

    [DllImport(SQLITE_DLL)]
    internal static extern void sqlite3_realcolnames(int db, int bset);

    [DllImport(SQLITE_DLL)]
    internal static extern IntPtr sqlite3_column_text16_interop(int stmt, int index);
    internal static extern IntPtr sqlite3_column_text16_interop(int stmt, int index, out int len);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern int sqlite3_open16_interop(string utf16Filename, out int db);

    [DllImport(SQLITE_DLL)]
    internal static extern IntPtr sqlite3_errmsg16_interop(int db);
    internal static extern IntPtr sqlite3_errmsg16_interop(int db, out int len);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern int sqlite3_prepare16_interop(int db, string strSql, int sqlLen, out int stmt, out IntPtr ptrRemain);
    internal static extern int sqlite3_prepare16_interop(int db, string strSql, int sqlLen, out int stmt, out IntPtr ptrRemain, out int len);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern int sqlite3_bind_text16_interop(int stmt, int index, string value, int nlen, int nTransient);

    [DllImport(SQLITE_DLL)]
    internal static extern IntPtr sqlite3_column_name16_interop(int stmt, int index);
    internal static extern IntPtr sqlite3_column_name16_interop(int stmt, int index, out int len);

    [DllImport(SQLITE_DLL)]
    internal static extern IntPtr sqlite3_column_decltype16_interop(int stmt, int index);
    internal static extern IntPtr sqlite3_column_decltype16_interop(int stmt, int index, out int len);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern int sqlite3_create_collation16_interop(int db, string strName, int nType, int nArgs, SQLiteCollation func, out int nCookie);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern int sqlite3_create_function16_interop(int db, string strName, int nArgs, int nType, SQLiteCallback func, SQLiteCallback funcstep, SQLiteCallback funcfinal, out int nCookie);

    [DllImport(SQLITE_DLL)]
    internal static extern IntPtr sqlite3_value_text16_interop(int p);
    internal static extern IntPtr sqlite3_value_text16_interop(int p, out int len);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern void sqlite3_result_error16_interop(int context, string strName, int nLen);

    [DllImport(SQLITE_DLL, CharSet = CharSet.Unicode)]
    internal static extern void sqlite3_result_text16_interop(int context, string strName, int nLen, int pvReserved);
  }