CqlBlock.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Map / ViewGeneration / CqlGeneration / CqlBlock.cs / 1305376 / CqlBlock.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

 
using System.Data.Common.Utils;
using System.Collections.Generic;
using System.Data.Mapping.ViewGeneration.Structures;
using System.Collections.ObjectModel; 
using System.Text;
using System.Diagnostics; 
 
namespace System.Data.Mapping.ViewGeneration.CqlGeneration
{ 

    // A class that holds an expression of the form SELECT .. FROM .. WHERE
    // Essentially, it is a structure allows us to generate Cql query in a
    // localized manner, i.e., all global decisions about nulls, constants, 
    // case statements, etc have already been made
    internal abstract class CqlBlock : InternalBase 
    { 

        // effects: Initializes a CqlBlock with the SELECT (slotinfos), FROM 
        // (children), WHERE (whereClause), AS (blockAliasNum)
        protected CqlBlock(SlotInfo[] slotInfos, List children,
                           BoolExpression whereClause, CqlIdentifiers identifiers, int blockAliasNum)
        { 
            m_slots = new ReadOnlyCollection(slotInfos);
            m_children = new ReadOnlyCollection(children); 
            m_whereClause = whereClause; 
            m_blockAlias = identifiers.GetBlockAlias(blockAliasNum);
        } 

        #region Fields
        private ReadOnlyCollection m_slots; // essentially, SELECT
        private ReadOnlyCollection m_children; // FROM 
        private BoolExpression m_whereClause; // WHERE
        private string m_blockAlias; // AS ... for cql generation 
        #endregion 

        #region Properties 
        // effects: Returns the slot being projected at slotNum. If no slot
        // is being projected, returns null
        internal ProjectedSlot ProjectedSlot(int slotNum)
        { 
            Debug.Assert(slotNum < m_slots.Count, "Slotnum too high");
            return m_slots[slotNum].SlotValue; 
        } 

        // effects: Returns the whereclause of this block (WHERE) 
        protected BoolExpression WhereClause
        {
            get { return m_whereClause; }
        } 

        // effects: Returns all the child blocks of this block (FROM) 
        protected ReadOnlyCollection Children 
        {
            get { return m_children; } 
        }

        // effects: Returns all the slots for this block (SELECT)
        internal ReadOnlyCollection Slots 
        {
            get { return m_slots; } 
            set { m_slots = value; } 
        }
        #endregion 

        #region Abstract Methods
        // effects: Returns a string corresponding to the Cql representation
        // of this block (and its children below). 
        internal abstract StringBuilder AsCql(StringBuilder builder, bool isTopLevel, int indentLevel);
        #endregion 
 
        #region Methods
        // effects: Returns a string that has an alias for the FROM part of 
        // this block or the whole block itself that can be used for "AS"
        internal string CqlAlias
        {
            get { return m_blockAlias; } 
        }
 
        // effects: Returns true iff slotNum is being projected by this block 
        internal bool IsProjected(int slotNum)
        { 
            Debug.Assert(slotNum < m_slots.Count, "Slotnum too high");
            return m_slots[slotNum].IsProjected;
        }
 
        protected void GenerateProjectedtList(StringBuilder builder, int indentLevel, string blockAlias, bool asForCaseStatementsOnly)
        { 
            GenerateProjectedtList(builder, indentLevel, blockAlias, CellQuery.SelectDistinct.No, asForCaseStatementsOnly); 
        }
 
        // effects: Generates a "SELECT A, B, C, .." for all the slots in this
        // if asForCaseStatementsOnly is true, generates aliases, ie., foo AS
        // bar for CaseStatements only. Otherwise, generates them for all slots
        protected void GenerateProjectedtList(StringBuilder builder, int indentLevel, 
                                              string blockAlias, CellQuery.SelectDistinct selectDistinct, bool asForCaseStatementsOnly)
        { 
            StringUtil.IndentNewLine(builder, indentLevel); 
            builder.Append("SELECT ");
 
            if (selectDistinct == CellQuery.SelectDistinct.Yes)
            {
                builder.Append("DISTINCT ");
            } 

            List projectedExpressions = new List(); 
            bool isFirst = true; 
            foreach (SlotInfo slotInfo in Slots)
            { 
                if (false == slotInfo.IsRequiredByParent)
                {
                    // Ignore slots that are not needed
                    continue; 
                }
                if (isFirst == false) 
                { 
                    builder.Append(", ");
                } 

                // Note: We call AsCql and not AliasName on
                // slotInfo since we do want to pick the right reference to
                // the slot from the appropriate child 
                if (false == asForCaseStatementsOnly)
                { 
                    StringUtil.IndentNewLine(builder, indentLevel + 1); 
                }
                slotInfo.AsCql(builder, blockAlias, indentLevel); 

                // Print the field alias for constants (booleans and regular constants). Also
                // case statements need the alias as well.
                // We also add it for extent cql blocks for all fields and 
                // finally we need  IS NOT NULL for boolean conditions
 
                if (slotInfo.SlotValue is CaseStatementProjectedSlot || 
                    slotInfo.SlotValue is BooleanProjectedSlot ||
                    slotInfo.SlotValue is ConstantProjectedSlot || 
                    asForCaseStatementsOnly == false ||
                    slotInfo.IsEnforcedNotNull)
                {
 
                    builder.Append(" AS ")
                           .Append(slotInfo.CqlFieldAlias); 
                } 
                isFirst = false;
            } 

            // Get the slots as A, B, C, ...
            StringUtil.ToSeparatedString(builder, projectedExpressions, ", ", null);
            StringUtil.IndentNewLine(builder, indentLevel); 
        }
 
        internal override void ToCompactString(StringBuilder builder) 
        {
            for (int i = 0; i < m_slots.Count; i++) 
            {
                StringUtil.FormatStringBuilder(builder, "{0}: ", i);
                m_slots[i].ToCompactString(builder);
                builder.Append(' '); 
            }
            m_whereClause.ToCompactString(builder); 
        } 
        #endregion
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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CqlBlock.cs source code in C# .NET

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