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(*
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* IBX For Lazarus (Firebird Express)
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*
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* The contents of this file are subject to the Initial Developer's
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* Public License Version 1.0 (the "License"); you may not use this
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* file except in compliance with the License. You may obtain a copy
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* of the License here:
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*
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* http://www.firebirdsql.org/index.php?op=doc&id=idpl
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
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* implied. See the License for the specific language governing rights
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* and limitations under the License.
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*
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* The Initial Developer of the Original Code is Tony Whyman.
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*
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* The Original Code is (C) 2014 Tony Whyman, MWA Software
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* (http://www.mwasoftware.co.uk).
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*
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* All Rights Reserved.
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*
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* Contributor(s): ______________________________________.
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*
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*)
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unit IBSQLParser;
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{$Mode Delphi}
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{$codepage UTF8}
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interface
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uses Classes, DB, IBUtils;
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{
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The SQL Parser is a partial SQL Parser intended to parser a Firebird DML (Select)
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statement with the intention of being able to modify the "Where", Having" and
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"Order By" clauses. It is not an SQL validator as while invalid SQL may be detected,
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there are many cases of non-compliant SQL that will still be parsed successfully.
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In use, when a TSelectSQLParser object is created, it is passed a Select SQL Statement
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that is then parsed into its constituent clauses. CTEs are brought out separately, as is
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each union. The main clauses are made visible as text properties. Some, such as the
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order by clause can be replaced fully. The Where and Having Clauses are manipulated by
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the Add2WhereClause and the Add2HavingClause.
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Add2WhereClause allows an SQL Condition statement (e.g. A = 1) to be appended to the
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current WhereClause, ANDing or ORing in the new condition. Normally, Add2WhereClause
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only manipulates the first Select in a UNION, and conditions must be applied separately
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to each member of the union. However, Add2WhereClause can also apply the same SQL
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condition to each member of the UNION.
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Add2HavingClause behaves identically, except that it applies to the Having Clause.
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TSelectSQLParser.Reset will return the Where, Having and OrderBy Clauses of all members
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of the Union to their initial state. ResetWhereClause, ResetHavingClause and
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ResetOrderByClause allow each clause to be individually reset to their initial
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state.
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The property SQLText is used to access the current Select SQL statement including
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CTEs and UNIONs and modified clauses.
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}
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type
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{ TSelectSQLTokeniser }
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{The select SQL tokeniser returns each successive clause. The token returned
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identifies the reserved word that starts the clause. e.g. sqltFrom and the tokentext
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is the remainder of the clause.}
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TSelectSQLTokeniser = class(TSQLwithNamedParamsTokeniser)
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private
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type
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TSQLState = (stDefault, stWith, stInCTE, stInRecursiveCTE, stCTEAs, stInNextCTE,
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stInSelect, stInFrom,stInWhere,stInGroupBy,
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stInHaving,stInPlan, stInUnion, stInUnionAll, stUnionEnd,
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stInOrderBy, stInRows, stNotASelectStmt);
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TSQLStates = set of TSQLState;
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private
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FSQLState: TSQLState;
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FNested: integer;
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FNextToken: TSQLTokens;
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FPrevCTEToken: TSQLTokens;
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FClause: string;
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FParamList: TStrings;
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FHasText: boolean;
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FUnionMember: boolean;
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function GetNotaSelectStmt: boolean;
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protected
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FCTEName: string;
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procedure Assign(source: TSQLTokeniser); override;
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function TokenFound(var token: TSQLTokens): boolean; override;
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procedure Reset; override;
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public
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constructor Create(UnionMember: boolean);
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destructor Destroy; override;
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procedure Clear; virtual;
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property ParamList: TStrings read FParamList;
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property NotaSelectStmt: boolean read GetNotaSelectStmt;
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end;
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{ TSelectSQLParser }
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TSelectSQLParser = class(TSelectSQLTokeniser)
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public
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type
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PCTEDef = ^TCTEDef;
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TCTEDef = record
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Recursive: boolean;
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Name: string;
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Text: string;
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end;
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private
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FDataSet: TDataSet;
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FOwner: TSelectSQLParser;
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FOnSQLChanging: TNotifyEvent;
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FDestroying: boolean;
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{Properties set after analysis}
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FSelectClause: string;
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FFromClause: string;
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FWhereClause: string;
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FGroupClause: string;
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FHavingClause: string;
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FPlanClause: string;
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FUnionAll: boolean;
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FOrderByClause: string;
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FRowsClause: string;
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FUnion: TSelectSQLParser;
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FCTEs: array of PCTEDef;
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{Saved values}
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FOriginalWhereClause: string;
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FOriginalOrderByClause: string;
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FOriginalHavingClause: string;
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{Input buffer}
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FInString: string;
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FIndex: integer;
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procedure AnalyseSQL;
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function GetCTE(Index: integer): PCTEDef;
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function GetCTECount: integer;
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function AddCTE(aName: string; Recursive: boolean; text: string): PCTEDef;
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procedure FlushCTEs;
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function GetSQLText: string;
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procedure SetSelectClause(const Value: string);
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procedure SetOrderByClause(const Value: string);
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procedure SetGroupClause(const Value: string);
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procedure SetFromClause(const Value: string);
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protected
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constructor Create(aOwner: TSelectSQLParser); overload;
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procedure Assign(source: TSQLTokeniser); override;
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procedure Changed;
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function GetChar: char; override;
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public
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constructor Create(aDataSet: TDataSet; SQLText: TStrings); overload;
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constructor Create(aDataSet: TDataSet; const SQLText: string); overload;
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destructor Destroy; override;
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procedure Add2WhereClause(const Condition: string; OrClause: boolean=false;
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IncludeUnions: boolean = false);
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procedure Add2HavingClause(const Condition: string; OrClause: boolean=false;
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IncludeUnions: boolean = false);
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procedure Clear; override;
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procedure DropUnion;
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function GetFieldPosition(AliasName: string): integer;
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procedure ResetWhereClause;
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procedure ResetHavingClause;
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procedure ResetOrderByClause;
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procedure RestoreClauseValues;
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property CTEs[Index: integer]: PCTEDef read GetCTE;
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property CTECount: integer read GetCTECount;
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property DataSet: TDataSet read FDataSet;
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property SelectClause: string read FSelectClause write SetSelectClause;
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property FromClause: string read FFromClause write SetFromClause;
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property GroupClause: string read FGroupClause write SetGroupClause;
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property HavingClause: string read FHavingClause write FHavingClause;
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property PlanClause: string read FPlanClause;
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property WhereClause: string read FWhereClause write FWhereClause;
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property OrderByClause: string read FOrderByClause write SetOrderByClause;
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property RowsClause: string read FRowsClause;
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property SQLText: string read GetSQLText;
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property Union: TSelectSQLParser read FUnion;
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property UnionAll: boolean read FUnionAll write FUnionAll;
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{When true this is joined by "Union All" to the parent Select}
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property OnSQLChanging: TNotifyEvent read FOnSQLChanging write FOnSQLChanging;
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end;
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TFilterCallback = procedure(Parser: TSelectSQLParser; Key: integer) of object;
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implementation
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uses Sysutils, IBCustomDataSet, IB, IBMessages;
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{ TSelectSQLParser }
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procedure TSelectSQLParser.AnalyseSQL;
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var token: TSQLTokens;
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begin
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while not EOF do
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begin
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token := GetNextToken;
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// writeln('HL: ',token,',',TokenText);
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case token of
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sqltSelect:
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FSelectClause := Trim(TokenText);
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sqltWith:
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AddCTE(FCTEName,false,Trim(TokenText));
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sqltRecursive:
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AddCTE(FCTEName,true,Trim(TokenText));
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sqltFrom:
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FFromClause := Trim(TokenText);
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sqltWhere:
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FWhereClause := Trim(TokenText);
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sqltGroup:
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FGroupClause := Trim(TokenText);
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sqltHaving:
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FHavingClause := Trim(TokenText);
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sqltPlan:
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FPlanClause := Trim(TokenText);
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sqltUnion:
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begin
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FUnion := TSelectSQLParser.Create(self);
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Assign(FUnion); {copy back state}
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FNextToken := sqltSpace;
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end;
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sqltOrder:
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FOrderByClause := Trim(TokenText);
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sqltRows:
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FRowsClause := Trim(TokenText);
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sqltAll:
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begin
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FUnion := TSelectSQLParser.Create(self);
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FUnion.FUnionAll := true;
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Assign(FUnion); {copy back state}
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FNextToken := sqltSpace;
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end;
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end;
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end;
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FOriginalWhereClause := WhereClause;
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FOriginalHavingClause := HavingClause;
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FOriginalOrderByClause := OrderByClause
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end;
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function TSelectSQLParser.GetCTE(Index: integer): PCTEDef;
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begin
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if (Index < 0) or (index >= GetCTECount) then
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raise Exception.Create('CTE Index out of bounds');
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Result := FCTEs[Index]
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end;
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function TSelectSQLParser.GetCTECount: integer;
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begin
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Result := Length(FCTEs);
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end;
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function TSelectSQLParser.AddCTE(aName: string; Recursive: boolean; text: string
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): PCTEDef;
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var index: integer;
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begin
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new(Result);
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Result^.Name := aName;
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Result^.Recursive := Recursive;
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Result^.text := text;
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index := Length(FCTEs);
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SetLength(FCTEs,index+1);
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FCTEs[index] := Result;
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end;
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procedure TSelectSQLParser.FlushCTEs;
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var i: integer;
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begin
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for i := 0 to Length(FCTEs) - 1 do
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dispose(FCTEs[i]);
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SetLength(FCTEs,0);
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end;
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function TSelectSQLParser.GetSQLText: string;
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var SQL: TStringList;
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I: integer;
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begin
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SQL := TStringList.Create;
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try
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for I := 0 to CTECount - 1 do
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begin
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if I = 0 then
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begin
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if CTEs[I]^.Recursive then
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SQL.Add('WITH RECURSIVE ' + CTEs[I]^.Name + ' AS ' + CTES[I]^.Text )
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else
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SQL.Add('WITH ' + CTEs[I]^.Name + ' AS ' + CTES[I]^.Text)
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end
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else
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begin
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SQL.Strings[SQL.Count-1] := SQL.Strings[SQL.Count-1] + ',';
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SQL.Add(CTEs[I]^.Name + ' AS ' + CTES[I]^.Text)
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end
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end;
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if CTECount > 0 then
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SQL.Add('');
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SQL.Add('SELECT ' + SelectClause);
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SQL.Add('FROM ' + FromClause);
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if WhereClause <> '' then
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SQL.Add('WHERE ' + WhereClause);
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if GroupClause <> '' then
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SQL.Add('GROUP BY ' + GroupClause);
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if HavingClause <> '' then
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SQL.Add('HAVING ' + HavingClause);
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if PlanClause <> '' then
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SQL.Add('PLAN ' + PlanClause);
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if Union <> nil then
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begin
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if Union.UnionAll then
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SQL.Add('UNION ALL')
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else
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SQL.Add('UNION');
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SQL.Add(Union.SQLText)
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end;
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if OrderByClause <> '' then
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SQL.Add('ORDER BY ' + OrderByClause);
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if RowsClause <> '' then
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SQL.Add('ROWS ' + RowsClause);
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Result := SQL.Text
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finally
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SQL.Free
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end
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end;
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procedure TSelectSQLParser.SetSelectClause(const Value: string);
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begin
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if FSelectClause <> Value then
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begin
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FSelectClause := Value;
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Changed
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end;
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end;
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procedure TSelectSQLParser.SetOrderByClause(const Value: string);
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begin
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if Union <> nil then
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Union.OrderByClause := Value
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else
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if FOrderByClause <> Value then
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begin
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FOrderByClause := Value;
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Changed
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end;
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end;
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procedure TSelectSQLParser.SetGroupClause(const Value: string);
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begin
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if FGroupClause <> Value then
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begin
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FGroupClause := Value;
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Changed
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end;
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end;
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procedure TSelectSQLParser.SetFromClause(const Value: string);
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begin
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if FFromClause <> Value then
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begin
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FFromClause := Value;
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Changed
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end;
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end;
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constructor TSelectSQLParser.Create(aOwner: TSelectSQLParser);
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begin
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inherited Create(aOwner <> nil);
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FOwner := aOwner;
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if assigned(FOwner) then
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begin
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FDataSet := FOwner.DataSet;
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{copy state}
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Assign(aOwner);
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end;
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AnalyseSQL;
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end;
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procedure TSelectSQLParser.Assign(source: TSQLTokeniser);
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begin
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inherited Assign(source);
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if source is TSelectSQLParser then
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begin
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FInString := TSelectSQLParser(source).FInString;
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FIndex := TSelectSQLParser(source).FIndex;
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end;
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end;
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procedure TSelectSQLParser.Changed;
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begin
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if FOwner <> nil then
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FOwner.Changed
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else
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if assigned(FOnSQLChanging) and not FDestroying then
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OnSQLChanging(self)
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end;
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function TSelectSQLParser.GetChar: char;
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begin
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if FIndex <= Length(FInString) then
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begin
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Result := FInString[FIndex];
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Inc(FIndex);
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end
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else
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Result := #0;
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end;
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constructor TSelectSQLParser.Create(aDataSet: TDataSet; SQLText: TStrings);
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begin
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FDataSet := aDataSet;
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FInString := SQLText.Text;
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FIndex := 1;
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Create(nil);
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end;
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constructor TSelectSQLParser.Create(aDataSet: TDataSet; const SQLText: string);
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begin
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FDataSet := aDataSet;
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FInString := SQLText;
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FIndex := 1;
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Create(nil);
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end;
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destructor TSelectSQLParser.Destroy;
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begin
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FDestroying := true;
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Clear;
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inherited Destroy;
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end;
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procedure TSelectSQLParser.Add2WhereClause(const Condition: string;
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OrClause: boolean; IncludeUnions: boolean);
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begin
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if WhereClause <> '' then
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if OrClause then
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FWhereClause := '(' + WhereClause + ') OR (' + Condition + ')'
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else
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FWhereClause := '(' + WhereClause + ') AND (' + Condition + ')'
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else
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FWhereClause := Condition;
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if IncludeUnions and (Union <> nil) then
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Union.Add2WhereClause(Condition,OrClause,IncludeUnions);
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Changed;
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end;
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procedure TSelectSQLParser.Add2HavingClause(const Condition: string;
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OrClause: boolean; IncludeUnions: boolean);
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begin
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if HavingClause <> '' then
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if OrClause then
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FHavingClause := '(' + HavingClause + ') OR (' + Condition + ')'
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else
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FHavingClause := '(' + HavingClause + ') AND (' + Condition + ')'
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else
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FHavingClause := Condition;
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if IncludeUnions and (Union <> nil) then
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Union.Add2HavingClause(Condition,OrClause,IncludeUnions);
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Changed;
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end;
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procedure TSelectSQLParser.Clear;
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begin
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inherited Clear;
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DropUnion;
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FlushCTEs;
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FInString := '';
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FIndex := 1;
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FSelectClause := '';
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FFromClause := '';
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FWhereClause := '';
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FGroupClause := '';
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FHavingClause := '';
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FPlanClause := '';
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FUnionAll := false;
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FOrderByClause := '';
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FOriginalWhereClause := '';
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FOriginalOrderByClause := '';
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FOriginalHavingClause := '';
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end;
|
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procedure TSelectSQLParser.DropUnion;
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begin
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if FUnion <> nil then
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begin
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FUnion.Free;
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FUnion := nil;
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Changed
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end
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end;
|
499 |
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function TSelectSQLParser.GetFieldPosition(AliasName: string): integer;
|
501 |
begin
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502 |
if assigned(FDataSet) and (FDataSet is TIBCustomDataset) then
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Result := TIBCustomDataset(FDataSet).GetFieldPosition(AliasName)
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else
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Result := 0;
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end;
|
507 |
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procedure TSelectSQLParser.ResetWhereClause;
|
509 |
begin
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FWhereClause := FOriginalWhereClause;
|
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if Union <> nil then
|
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Union.ResetWhereClause;
|
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Changed
|
514 |
end;
|
515 |
|
516 |
procedure TSelectSQLParser.ResetHavingClause;
|
517 |
begin
|
518 |
FHavingClause := FOriginalHavingClause;
|
519 |
if Union <> nil then
|
520 |
Union.ResetHavingClause;
|
521 |
Changed
|
522 |
end;
|
523 |
|
524 |
procedure TSelectSQLParser.ResetOrderByClause;
|
525 |
begin
|
526 |
FOrderbyClause := FOriginalOrderByClause;
|
527 |
if Union <> nil then
|
528 |
Union.ResetOrderByClause;
|
529 |
Changed
|
530 |
end;
|
531 |
|
532 |
procedure TSelectSQLParser.RestoreClauseValues;
|
533 |
begin
|
534 |
ResetWhereClause;
|
535 |
ResetHavingClause;
|
536 |
ResetOrderByClause
|
537 |
end;
|
538 |
|
539 |
{ TSelectSQLTokeniser }
|
540 |
|
541 |
function TSelectSQLTokeniser.GetNotaSelectStmt: boolean;
|
542 |
begin
|
543 |
Result := FSQLState = stNotASelectStmt;
|
544 |
end;
|
545 |
|
546 |
procedure TSelectSQLTokeniser.Assign(source: TSQLTokeniser);
|
547 |
begin
|
548 |
inherited Assign(source);
|
549 |
if source is TSelectSQLTokeniser then
|
550 |
begin
|
551 |
FSQLState := TSelectSQLTokeniser(source).FSQLState;
|
552 |
FNested := TSelectSQLTokeniser(source).FNested;
|
553 |
FNextToken := TSelectSQLTokeniser(source).FNextToken;
|
554 |
FPrevCTEToken := TSelectSQLTokeniser(source).FPrevCTEToken;
|
555 |
FClause := TSelectSQLTokeniser(source).FClause;
|
556 |
end;
|
557 |
end;
|
558 |
|
559 |
function TSelectSQLTokeniser.TokenFound(var token: TSQLTokens): boolean;
|
560 |
|
561 |
procedure swap(var a,b: TSQLTokens);
|
562 |
var c: TSQLTokens;
|
563 |
begin
|
564 |
c:= a;
|
565 |
a := b;
|
566 |
b := c;
|
567 |
end;
|
568 |
|
569 |
procedure ChangeState(AllowStates: TSQLStates; DoNesting: boolean);
|
570 |
var SaveState: TSQLState;
|
571 |
begin
|
572 |
SaveState := FSQLState;
|
573 |
if DoNesting then
|
574 |
case token of
|
575 |
sqltOpenBracket:
|
576 |
begin
|
577 |
Inc(FNested);
|
578 |
Exit;
|
579 |
end;
|
580 |
|
581 |
sqltCloseBracket:
|
582 |
Begin
|
583 |
Dec(FNested);
|
584 |
Exit;
|
585 |
end;
|
586 |
end;
|
587 |
|
588 |
if FNested = 0 then
|
589 |
case token of
|
590 |
sqltFrom:
|
591 |
FSQLState := stInFrom;
|
592 |
|
593 |
sqltWhere:
|
594 |
FSQLState := stInWhere;
|
595 |
|
596 |
sqltGroup:
|
597 |
FSQLState := stInGroupBy;
|
598 |
|
599 |
sqltHaving:
|
600 |
FSQLState := stInHaving;
|
601 |
|
602 |
sqltPlan:
|
603 |
FSQLState := stInPlan;
|
604 |
|
605 |
sqltUnion:
|
606 |
FSQLState := stInUnion;
|
607 |
|
608 |
sqltOrder:
|
609 |
begin
|
610 |
if FUnionMember then
|
611 |
{stop and return to owning object}
|
612 |
begin
|
613 |
ResetQueue(sqltEOF,'');
|
614 |
QueueToken(token);
|
615 |
ReleaseQueue;
|
616 |
token := sqltEOF;
|
617 |
FSQLState := stUnionEnd;
|
618 |
end
|
619 |
else
|
620 |
FSQLState := stInOrderBy;
|
621 |
end;
|
622 |
|
623 |
sqltRows:
|
624 |
if FUnionMember then
|
625 |
{stop and return to owning object}
|
626 |
begin
|
627 |
ResetQueue(sqltEOF,'');
|
628 |
QueueToken(token);
|
629 |
ReleaseQueue;
|
630 |
token := sqltEOF;
|
631 |
FSQLState := stUnionEnd;
|
632 |
end
|
633 |
else
|
634 |
FSQLState := stInRows;
|
635 |
|
636 |
sqltAll:
|
637 |
FSQLState := stInUnionAll;
|
638 |
end;
|
639 |
if not (FSQLState in AllowStates + [stDefault]) then
|
640 |
FSQLState := SaveState
|
641 |
else
|
642 |
if SaveState <> FSQLState then
|
643 |
swap(token,FNextToken);
|
644 |
end;
|
645 |
|
646 |
var StateOnEntry: TSQLState;
|
647 |
DoNotReturnToken: boolean;
|
648 |
|
649 |
function TokenIncomplete: boolean;
|
650 |
begin
|
651 |
{we are not done if we are in not the default state and no state change,
|
652 |
unless we are a union member and the state is stUnionEnd}
|
653 |
Result := (FUnionMember and (StateOnEntry = stUnionEnd)) or
|
654 |
((StateOnEntry = stDefault) or (StateOnEntry = FSQLState));
|
655 |
end;
|
656 |
|
657 |
begin
|
658 |
Result := inherited TokenFound(token);
|
659 |
if not Result or NotaSelectStmt then Exit;
|
660 |
|
661 |
// writeln(token);
|
662 |
StateOnEntry := FSQLState;
|
663 |
DoNotReturnToken := false;
|
664 |
|
665 |
if not (token in [sqltComment,sqltCommentLine]) then
|
666 |
begin
|
667 |
if token in [sqltParam, sqltQuotedParam] then
|
668 |
FParamList.Add(TokenText);
|
669 |
|
670 |
if (token = sqltEOF) or ((FNested = 0) and
|
671 |
not (token in [sqltQuotedString,sqltIdentifierInDoubleQuotes]) and
|
672 |
(TokenText = DefaultTerminator)) then
|
673 |
begin
|
674 |
if not FHasText then
|
675 |
FSQLState := stNotASelectStmt {empty statements are not select statements}
|
676 |
else
|
677 |
if FSQLState <> stUnionEnd then
|
678 |
FSQLState := stDefault;
|
679 |
swap(token,FNextToken);
|
680 |
end
|
681 |
else
|
682 |
if not (token in [sqltSpace,sqltEOL,sqltCR]) then
|
683 |
case FSQLState of
|
684 |
stDefault:
|
685 |
begin
|
686 |
if FNested = 0 then {not inside a pair of brackets}
|
687 |
case token of
|
688 |
sqltSelect:
|
689 |
FSQLState := stInSelect;
|
690 |
|
691 |
sqltWith:
|
692 |
FSQLState := stWith;
|
693 |
|
694 |
else
|
695 |
FSQLState := stNotASelectStmt;
|
696 |
end;
|
697 |
FNextToken := token;
|
698 |
end;
|
699 |
|
700 |
stWith:
|
701 |
begin
|
702 |
case token of
|
703 |
sqltRecursive:
|
704 |
begin
|
705 |
FSQLState := stInRecursiveCTE;
|
706 |
FNextToken := token;
|
707 |
end;
|
708 |
|
709 |
sqltIdentifier:
|
710 |
begin
|
711 |
FCTEName := TokenText;
|
712 |
FSQLState := stCTEAs;
|
713 |
FPrevCTEToken := FNextToken;
|
714 |
token := FNextToken;
|
715 |
end
|
716 |
|
717 |
else
|
718 |
IBError(ibxErrorParsing,['with']);
|
719 |
end;
|
720 |
DoNotReturnToken := true;
|
721 |
end;
|
722 |
|
723 |
stInRecursiveCTE:
|
724 |
case token of
|
725 |
sqltIdentifier:
|
726 |
begin
|
727 |
FCTEName := TokenText;
|
728 |
FSQLState := stCTEAs;
|
729 |
token := FNextToken;
|
730 |
FPrevCTEToken := FNextToken;
|
731 |
DoNotReturnToken := true;
|
732 |
end;
|
733 |
|
734 |
else
|
735 |
IBError(ibxErrorParsing,['with recursive']);
|
736 |
end;
|
737 |
|
738 |
stInNextCTE:
|
739 |
case token of
|
740 |
sqltIdentifier:
|
741 |
begin
|
742 |
FCTEName := TokenText;
|
743 |
FSQLState := stCTEAs;
|
744 |
token := FPrevCTEToken;
|
745 |
DoNotReturnToken := true;
|
746 |
end;
|
747 |
|
748 |
else
|
749 |
IBError(ibxErrorParsing,['with']);
|
750 |
end;
|
751 |
|
752 |
stCTEAs:
|
753 |
if token = sqltAs then
|
754 |
begin
|
755 |
FSQLState := stInCTE;
|
756 |
DoNotReturnToken := true;
|
757 |
end
|
758 |
else
|
759 |
IBError(ibxErrorParsing,['with']);
|
760 |
|
761 |
stInCTE:
|
762 |
begin
|
763 |
case token of
|
764 |
sqltOpenBracket:
|
765 |
Inc(FNested);
|
766 |
|
767 |
sqltCloseBracket:
|
768 |
Dec(FNested);
|
769 |
|
770 |
sqltComma:
|
771 |
if FNested = 0 then
|
772 |
begin
|
773 |
FSQLState := stInNextCTE;
|
774 |
token := FNextToken;
|
775 |
end;
|
776 |
|
777 |
sqltSelect:
|
778 |
if FNested = 0 then
|
779 |
begin
|
780 |
FSQLState := stInSelect;
|
781 |
swap(FNextToken,token);
|
782 |
end;
|
783 |
end;
|
784 |
end;
|
785 |
|
786 |
stInSelect:
|
787 |
ChangeState([stInFrom],true);
|
788 |
|
789 |
stInFrom:
|
790 |
ChangeState([stInWhere,stInGroupBy, stInHaving,stInPlan, stInUnion,stUnionEnd,
|
791 |
stInOrderBy, stInRows],true);
|
792 |
|
793 |
stInWhere:
|
794 |
ChangeState([stInGroupBy, stInHaving,stInPlan, stInUnion,stUnionEnd,
|
795 |
stInOrderBy, stInRows],true);
|
796 |
|
797 |
stInGroupBy:
|
798 |
if token = sqltBy then
|
799 |
begin
|
800 |
FClause := '';
|
801 |
SetTokenText('');
|
802 |
DoNotReturnToken := true;
|
803 |
end
|
804 |
else
|
805 |
ChangeState([stInHaving,stInPlan, stInUnion, stUnionEnd, stInOrderBy, stInRows],false);
|
806 |
|
807 |
stInHaving:
|
808 |
ChangeState([stInPlan, stInUnion, stUnionEnd, stInOrderBy, stInRows],true);
|
809 |
|
810 |
stInPlan:
|
811 |
ChangeState([stInUnion, stUnionEnd, stInOrderBy, stInRows],true);
|
812 |
|
813 |
stInUnion:
|
814 |
case token of
|
815 |
sqltAll:
|
816 |
begin
|
817 |
FSQLState := stDefault;
|
818 |
FNextToken := token;
|
819 |
end;
|
820 |
else
|
821 |
begin
|
822 |
ResetQueue(token);
|
823 |
ReleaseQueue;
|
824 |
swap(token,FNextToken);
|
825 |
FSQLState := stDefault;
|
826 |
end;
|
827 |
end;
|
828 |
|
829 |
stUnionEnd: {On return from union clause}
|
830 |
ChangeState([stInOrderBy, stInRows],false);
|
831 |
|
832 |
stInOrderBy:
|
833 |
if token = sqltBy then
|
834 |
begin
|
835 |
FClause := '';
|
836 |
SetTokenText('');
|
837 |
DoNotReturnToken := true;
|
838 |
end
|
839 |
else
|
840 |
ChangeState([stInRows],false);
|
841 |
|
842 |
stInRows:
|
843 |
ChangeState([],false);
|
844 |
|
845 |
end;
|
846 |
|
847 |
{On EOF or state change return the next element, otherwise just add to text buffer}
|
848 |
|
849 |
if (token <> sqltEOF) and TokenIncomplete then
|
850 |
begin
|
851 |
if StateOnEntry <> stDefault then
|
852 |
case token of
|
853 |
sqltQuotedString:
|
854 |
FClause += '''' + SQLSafeString(TokenText) + '''';
|
855 |
|
856 |
sqltIdentifierInDoubleQuotes:
|
857 |
FClause += '"' + StringReplace(TokenText,'"','""',[rfReplaceAll]) + '"';
|
858 |
|
859 |
sqltParam:
|
860 |
FClause += ':' + TokenText;
|
861 |
|
862 |
sqltQuotedParam:
|
863 |
FClause += ':"' + StringReplace(TokenText,'"','""',[rfReplaceAll]) + '"';
|
864 |
|
865 |
else
|
866 |
FClause += TokenText;
|
867 |
end;
|
868 |
DoNotReturnToken := true;
|
869 |
end
|
870 |
else
|
871 |
begin
|
872 |
FHasText := true;
|
873 |
SetTokenText(FClause);
|
874 |
FClause := '';
|
875 |
end;
|
876 |
|
877 |
end;
|
878 |
Result := not DoNotReturnToken ;
|
879 |
end;
|
880 |
|
881 |
procedure TSelectSQLTokeniser.Reset;
|
882 |
begin
|
883 |
inherited Reset;
|
884 |
FSQLState := stDefault;
|
885 |
FNested := 0;
|
886 |
FNextToken := sqltSpace;
|
887 |
end;
|
888 |
|
889 |
constructor TSelectSQLTokeniser.Create(UnionMember: boolean);
|
890 |
begin
|
891 |
inherited Create;
|
892 |
FUnionMember := UnionMember;
|
893 |
FParamList := TStringList.Create;
|
894 |
end;
|
895 |
|
896 |
destructor TSelectSQLTokeniser.Destroy;
|
897 |
begin
|
898 |
if assigned(FParamList) then FParamList.Free;
|
899 |
FParamList := nil;
|
900 |
inherited Destroy;
|
901 |
end;
|
902 |
|
903 |
procedure TSelectSQLTokeniser.Clear;
|
904 |
begin
|
905 |
Reset;
|
906 |
FHasText := false;
|
907 |
if assigned(FParamList) then
|
908 |
FParamList.Clear;
|
909 |
end;
|
910 |
|
911 |
|
912 |
|
913 |
end.
|
914 |
|
915 |
|