/// <summary> /// Write out the SKIP part of sql select statement /// It basically writes SKIP (X). /// </summary> /// <param name="writer"></param> /// <param name="sqlGenerator"></param> public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator) { writer.Write("SKIP ("); SkipCount.WriteSql(writer, sqlGenerator); writer.Write(")"); writer.Write(" "); }
/// <summary> /// Write out the FIRST part of sql select statement /// It basically writes FIRST (X). /// </summary> /// <param name="writer"></param> /// <param name="sqlGenerator"></param> public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator) { writer.Write("FIRST ("); FirstCount.WriteSql(writer, sqlGenerator); writer.Write(")"); writer.Write(" "); }
/// <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 (var o in _sqlFragments) { var str = (o as string); if (null != str) { writer.Write(str); } else { var sqlFragment = (o as ISqlFragment); if (null != sqlFragment) { sqlFragment.WriteSql(writer, sqlGenerator); } else { throw new InvalidOperationException(); } } } } }
/// <summary> /// Write this symbol out as a string for sql. This is just /// the new name of the symbol (which could be the same as the old name). /// /// We rename columns here if necessary. /// </summary> /// <param name="writer"></param> /// <param name="sqlGenerator"></param> public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator) { if (NeedsRenaming) { string newName; var i = sqlGenerator.AllColumnNames[NewName]; do { ++i; newName = Name + i.ToString(System.Globalization.CultureInfo.InvariantCulture); } while (sqlGenerator.AllColumnNames.ContainsKey(newName)); sqlGenerator.AllColumnNames[NewName] = i; // Prevent it from being renamed repeatedly. NeedsRenaming = false; NewName = newName; // Add this column name to list of known names so that there are no subsequent // collisions sqlGenerator.AllColumnNames[newName] = 0; } writer.Write(SqlGenerator.QuoteIdentifier(NewName)); }
/// <summary> /// Write out a SQL select statement as a string. /// We have to /// <list type="number"> /// <item>Check whether the aliases extents we use in this statement have /// to be renamed. /// We first create a list of all the aliases used by the outer extents. /// For each of the FromExtents( or AllJoinExtents if it is non-null), /// rename it if it collides with the previous list. /// </item> /// <item>Write each of the clauses (if it exists) as a string</item> /// </list> /// </summary> /// <param name="writer"></param> /// <param name="sqlGenerator"></param> public void WriteSql(SqlWriter writer, SqlGenerator sqlGenerator) { #region Check if FROM aliases need to be renamed // Create a list of the aliases used by the outer extents // JoinSymbols have to be treated specially. List <string> outerExtentAliases = null; if ((null != _outerExtents) && (0 < _outerExtents.Count)) { foreach (Symbol outerExtent in _outerExtents.Keys) { JoinSymbol joinSymbol = outerExtent as JoinSymbol; if (joinSymbol != null) { foreach (Symbol symbol in joinSymbol.FlattenedExtentList) { if (null == outerExtentAliases) { outerExtentAliases = new List <string>(); } outerExtentAliases.Add(symbol.NewName); } } else { if (null == outerExtentAliases) { outerExtentAliases = new List <string>(); } outerExtentAliases.Add(outerExtent.NewName); } } } // An then rename each of the FromExtents we have // If AllJoinExtents is non-null - it has precedence. // The new name is derived from the old name - we append an increasing int. List <Symbol> extentList = AllJoinExtents ?? _fromExtents; if (null != extentList) { foreach (Symbol fromAlias in extentList) { if ((null != outerExtentAliases) && outerExtentAliases.Contains(fromAlias.Name)) { int i = sqlGenerator.AllExtentNames[fromAlias.Name]; string newName; do { ++i; newName = fromAlias.Name + i.ToString(System.Globalization.CultureInfo.InvariantCulture); }while (sqlGenerator.AllExtentNames.ContainsKey(newName)); sqlGenerator.AllExtentNames[fromAlias.Name] = i; fromAlias.NewName = newName; // Add extent to list of known names (although i is always incrementing, "prefix11" can // eventually collide with "prefix1" when it is extended) sqlGenerator.AllExtentNames[newName] = 0; } // Add the current alias to the list, so that the extents // that follow do not collide with me. if (null == outerExtentAliases) { outerExtentAliases = new List <string>(); } outerExtentAliases.Add(fromAlias.NewName); } } #endregion // Increase the indent, so that the Sql statement is nested by one tab. writer.Indent += 1; // ++ can be confusing in this context writer.Write("SELECT "); if (IsDistinct) { writer.Write("DISTINCT "); } if (First != null) { First.WriteSql(writer, sqlGenerator); } if (Skip != null) { Skip.WriteSql(writer, sqlGenerator); } if ((_select == null) || Select.IsEmpty) { Debug.Assert(false); // we have removed all possibilities of SELECT *. writer.Write("*"); } else { Select.WriteSql(writer, sqlGenerator); } writer.WriteLine(); writer.Write("FROM "); From.WriteSql(writer, sqlGenerator); if ((_where != null) && !Where.IsEmpty) { writer.WriteLine(); writer.Write("WHERE "); Where.WriteSql(writer, sqlGenerator); } if ((_groupBy != null) && !GroupBy.IsEmpty) { writer.WriteLine(); writer.Write("GROUP BY "); GroupBy.WriteSql(writer, sqlGenerator); } if ((_orderBy != null) && !OrderBy.IsEmpty && (IsTopMost || First != null || Skip != null)) { writer.WriteLine(); writer.Write("ORDER BY "); OrderBy.WriteSql(writer, sqlGenerator); } --writer.Indent; }