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| ///////////////////////////////////////////////////////////////////////////
// //
// Copyright (c) 2015 by Charta Software B.V. //
// All rights reserved //
// //
// Version: 1.7.0.83525 //
// Web site: https://pascal.chartasoftware.com/ //
// //
// This code and information are provided "as is" without warranty of //
// any kind. Dissemination of this information or reproduction of //
// this material is strictly forbidden unless prior written permission //
// is obtained from Charta Software B.V.. //
// //
///////////////////////////////////////////////////////////////////////////
unit Sql.Variable;
interface
{$SCOPEDENUMS ON}
uses
Sql.Expression,
Sql.Statement,
Text;
type
TSqlVariableType = (System, User);
TSqlVariable = class(TObject)
private
FType: TSqlVariableType;
FIdentifier: TText;
public
constructor Create(Type_: TSqlVariableType; const Identifier: TText); virtual;
property Type_: TSqlVariableType read FType;
property Identifier: TText read FIdentifier;
end;
TSqlVariableReference = class(TSqlExpression)
public
Variable: TSqlVariable;
constructor Create(Variable: TSqlVariable); reintroduce; virtual;
function Copy(): TSqlExpression; override;
function CopyVariableReference(): TSqlVariableReference;
end;
TSqlSetVariable = class(TSqlStatement)
private
FValue: TSqlExpression;
procedure SetValue(const Value: TSqlExpression);
public
Variable: TSqlVariable;
constructor Create(Variable: TSqlVariable; Value: TSqlExpression); reintroduce; virtual;
destructor Destroy(); override;
function CopyStatement(): TSqlStatement; override;
function CopySetVariable(): TSqlSetVariable;
property Value: TSqlExpression read FValue write SetValue;
end;
implementation
{ TSqlVariable }
constructor TSqlVariable.Create(Type_: TSqlVariableType; const Identifier: TText);
begin
inherited Create();
FType := Type_;
FIdentifier := Identifier;
end;
{ TSqlVariableReference }
function TSqlVariableReference.Copy(): TSqlExpression;
begin
Result := CopyVariableReference();
end;
function TSqlVariableReference.CopyVariableReference: TSqlVariableReference;
begin
Result := TSqlVariableReference.Create(Variable);
end;
constructor TSqlVariableReference.Create(Variable: TSqlVariable);
begin
inherited Create();
Self.Variable := Variable;
end;
{ TSqlSetVariable }
function TSqlSetVariable.CopySetVariable(): TSqlSetVariable;
begin
Result := TSqlSetVariable.Create(Variable, Value.Copy);
end;
function TSqlSetVariable.CopyStatement(): TSqlStatement;
begin
Result := CopySetVariable();
end;
constructor TSqlSetVariable.Create(Variable: TSqlVariable; Value: TSqlExpression);
begin
inherited Create();
Self.Variable := Variable;
Self.Value := Value;
end;
destructor TSqlSetVariable.Destroy();
begin
Value.ReleaseReference();
inherited Destroy();
end;
procedure TSqlSetVariable.SetValue(const Value: TSqlExpression);
begin
if Value <> Self.Value then
begin
Value.AddReference();
Self.Value.ReleaseReference();
FValue := Value;
end;
end;
end.
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