SqlSelectStatement.cs source code in C# .NET

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Code:

/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / SqlClient / SqlGen / SqlSelectStatement.cs / 1305376 / SqlSelectStatement.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Diagnostics;
using System.Data.Common.CommandTrees;
 
namespace System.Data.SqlClient.SqlGen
{ 
    ///  
    /// A SqlSelectStatement represents a canonical SQL SELECT statement.
    /// It has fields for the 5 main clauses 
    /// 
    /// SELECT
    /// FROM
    /// WHERE 
    /// GROUP BY
    /// ORDER BY 
    ///  
    /// We do not have HAVING, since the CQT does not have such a node.
    /// Each of the fields is a SqlBuilder, so we can keep appending SQL strings 
    /// or other fragments to build up the clause.
    ///
    /// The FromExtents contains the list of inputs in use for the select statement.
    /// There is usually just one element in this - Select statements for joins may 
    /// temporarily have more than one.
    /// 
    /// If the select statement is created by a Join node, we maintain a list of 
    /// all the extents that have been flattened in the join in AllJoinExtents
    ///  
    /// in J(j1= J(a,b), c)
    /// FromExtents has 2 nodes JoinSymbol(name=j1, ...) and Symbol(name=c)
    /// AllJoinExtents has 3 nodes Symbol(name=a), Symbol(name=b), Symbol(name=c)
    ///  
    ///
    /// If any expression in the non-FROM clause refers to an extent in a higher scope, 
    /// we add that extent to the OuterExtents list.  This list denotes the list 
    /// of extent aliases that may collide with the aliases used in this select statement.
    /// It is set by . 
    /// An extent is an outer extent if it is not one of the FromExtents.
    ///
    ///
    ///  
    internal sealed class SqlSelectStatement : ISqlFragment
    { 
 
        /// 
        /// Whether the columns ouput by this sql statement were renamed from what given in the command tree. 
        /// 
        internal bool OutputColumnsRenamed
        {
            get; 
            set;
        } 
 
        /// 
        /// A dictionary of output columns 
        /// 
        internal Dictionary OutputColumns
        {
            get; 
            set;
        } 
 
        internal List AllJoinExtents
        { 
            get;
            // We have a setter as well, even though this is a list,
            // since we use this field only in special cases.
            set; 
        }
 
        private List fromExtents; 
        internal List FromExtents
        { 
            get
            {
                if (null == fromExtents)
                { 
                    fromExtents = new List();
                } 
                return fromExtents; 
            }
        } 

        private Dictionary outerExtents;
        internal Dictionary OuterExtents
        { 
            get
            { 
                if (null == outerExtents) 
                {
                    outerExtents = new Dictionary(); 
                }
                return outerExtents;
            }
        } 

        private readonly SqlSelectClauseBuilder select; 
        internal SqlSelectClauseBuilder Select 
        {
            get { return select; } 
        }

        private readonly SqlBuilder from = new SqlBuilder();
        internal SqlBuilder From 
        {
            get { return from; } 
        } 

 
        private SqlBuilder where;
        internal SqlBuilder Where
        {
            get 
            {
                if (null == where) 
                { 
                    where = new SqlBuilder();
                } 
                return where;
            }
        }
 
        private SqlBuilder groupBy;
        internal SqlBuilder GroupBy 
        { 
            get
            { 
                if (null == groupBy)
                {
                    groupBy = new SqlBuilder();
                } 
                return groupBy;
            } 
        } 

        private SqlBuilder orderBy; 
        public SqlBuilder OrderBy
        {
            get
            { 
                if (null == orderBy)
                { 
                    orderBy = new SqlBuilder(); 
                }
                return orderBy; 
            }
        }

        //indicates whether it is the top most select statement, 
        // if not Order By should be omitted unless there is a corresponding TOP
        internal bool IsTopMost 
        { 
            get;
            set; 
        }

        #region Internal Constructor
        internal SqlSelectStatement() 
        {
            this.select = new SqlSelectClauseBuilder(delegate() { return this.IsTopMost; }); 
        } 
        #endregion
 
        #region ISqlFragment Members

        /// 
        /// Write out a SQL select statement as a string. 
        /// We have to
        ///  
        /// 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.
        /// 
        /// Write each of the clauses (if it exists) as a string 
        /// 
        ///  
        ///  
        /// 
        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 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(); } 
                            outerExtentAliases.Add(symbol.NewName);
                        } 
                    }
                    else
                    {
                        if (null == outerExtentAliases) { outerExtentAliases = new List(); } 
                        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 extentList = this.AllJoinExtents ?? this.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(); }
                    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 

            this.select.WriteSql(writer, sqlGenerator);

            writer.WriteLine(); 
            writer.Write("FROM ");
            this.From.WriteSql(writer, sqlGenerator); 
 
            if ((null != this.where) && !this.Where.IsEmpty)
            { 
                writer.WriteLine();
                writer.Write("WHERE ");
                this.Where.WriteSql(writer, sqlGenerator);
            } 

            if ((null != this.groupBy) && !this.GroupBy.IsEmpty) 
            { 
                writer.WriteLine();
                writer.Write("GROUP BY "); 
                this.GroupBy.WriteSql(writer, sqlGenerator);
            }

            if ((null != this.orderBy) && !this.OrderBy.IsEmpty && (this.IsTopMost || this.Select.Top != null)) 
            {
                writer.WriteLine(); 
                writer.Write("ORDER BY "); 
                this.OrderBy.WriteSql(writer, sqlGenerator);
            } 

            --writer.Indent;
        }
 
        #endregion
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Diagnostics;
using System.Data.Common.CommandTrees;
 
namespace System.Data.SqlClient.SqlGen
{ 
    ///  
    /// A SqlSelectStatement represents a canonical SQL SELECT statement.
    /// It has fields for the 5 main clauses 
    /// 
    /// SELECT
    /// FROM
    /// WHERE 
    /// GROUP BY
    /// ORDER BY 
    ///  
    /// We do not have HAVING, since the CQT does not have such a node.
    /// Each of the fields is a SqlBuilder, so we can keep appending SQL strings 
    /// or other fragments to build up the clause.
    ///
    /// The FromExtents contains the list of inputs in use for the select statement.
    /// There is usually just one element in this - Select statements for joins may 
    /// temporarily have more than one.
    /// 
    /// If the select statement is created by a Join node, we maintain a list of 
    /// all the extents that have been flattened in the join in AllJoinExtents
    ///  
    /// in J(j1= J(a,b), c)
    /// FromExtents has 2 nodes JoinSymbol(name=j1, ...) and Symbol(name=c)
    /// AllJoinExtents has 3 nodes Symbol(name=a), Symbol(name=b), Symbol(name=c)
    ///  
    ///
    /// If any expression in the non-FROM clause refers to an extent in a higher scope, 
    /// we add that extent to the OuterExtents list.  This list denotes the list 
    /// of extent aliases that may collide with the aliases used in this select statement.
    /// It is set by . 
    /// An extent is an outer extent if it is not one of the FromExtents.
    ///
    ///
    ///  
    internal sealed class SqlSelectStatement : ISqlFragment
    { 
 
        /// 
        /// Whether the columns ouput by this sql statement were renamed from what given in the command tree. 
        /// 
        internal bool OutputColumnsRenamed
        {
            get; 
            set;
        } 
 
        /// 
        /// A dictionary of output columns 
        /// 
        internal Dictionary OutputColumns
        {
            get; 
            set;
        } 
 
        internal List AllJoinExtents
        { 
            get;
            // We have a setter as well, even though this is a list,
            // since we use this field only in special cases.
            set; 
        }
 
        private List fromExtents; 
        internal List FromExtents
        { 
            get
            {
                if (null == fromExtents)
                { 
                    fromExtents = new List();
                } 
                return fromExtents; 
            }
        } 

        private Dictionary outerExtents;
        internal Dictionary OuterExtents
        { 
            get
            { 
                if (null == outerExtents) 
                {
                    outerExtents = new Dictionary(); 
                }
                return outerExtents;
            }
        } 

        private readonly SqlSelectClauseBuilder select; 
        internal SqlSelectClauseBuilder Select 
        {
            get { return select; } 
        }

        private readonly SqlBuilder from = new SqlBuilder();
        internal SqlBuilder From 
        {
            get { return from; } 
        } 

 
        private SqlBuilder where;
        internal SqlBuilder Where
        {
            get 
            {
                if (null == where) 
                { 
                    where = new SqlBuilder();
                } 
                return where;
            }
        }
 
        private SqlBuilder groupBy;
        internal SqlBuilder GroupBy 
        { 
            get
            { 
                if (null == groupBy)
                {
                    groupBy = new SqlBuilder();
                } 
                return groupBy;
            } 
        } 

        private SqlBuilder orderBy; 
        public SqlBuilder OrderBy
        {
            get
            { 
                if (null == orderBy)
                { 
                    orderBy = new SqlBuilder(); 
                }
                return orderBy; 
            }
        }

        //indicates whether it is the top most select statement, 
        // if not Order By should be omitted unless there is a corresponding TOP
        internal bool IsTopMost 
        { 
            get;
            set; 
        }

        #region Internal Constructor
        internal SqlSelectStatement() 
        {
            this.select = new SqlSelectClauseBuilder(delegate() { return this.IsTopMost; }); 
        } 
        #endregion
 
        #region ISqlFragment Members

        /// 
        /// Write out a SQL select statement as a string. 
        /// We have to
        ///  
        /// 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.
        /// 
        /// Write each of the clauses (if it exists) as a string 
        /// 
        ///  
        ///  
        /// 
        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 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(); } 
                            outerExtentAliases.Add(symbol.NewName);
                        } 
                    }
                    else
                    {
                        if (null == outerExtentAliases) { outerExtentAliases = new List(); } 
                        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 extentList = this.AllJoinExtents ?? this.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(); }
                    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 

            this.select.WriteSql(writer, sqlGenerator);

            writer.WriteLine(); 
            writer.Write("FROM ");
            this.From.WriteSql(writer, sqlGenerator); 
 
            if ((null != this.where) && !this.Where.IsEmpty)
            { 
                writer.WriteLine();
                writer.Write("WHERE ");
                this.Where.WriteSql(writer, sqlGenerator);
            } 

            if ((null != this.groupBy) && !this.GroupBy.IsEmpty) 
            { 
                writer.WriteLine();
                writer.Write("GROUP BY "); 
                this.GroupBy.WriteSql(writer, sqlGenerator);
            }

            if ((null != this.orderBy) && !this.OrderBy.IsEmpty && (this.IsTopMost || this.Select.Top != null)) 
            {
                writer.WriteLine(); 
                writer.Write("ORDER BY "); 
                this.OrderBy.WriteSql(writer, sqlGenerator);
            } 

            --writer.Indent;
        }
 
        #endregion
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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