protected override Expression VisitCase(CaseExpression caseExpression)
{
var parentSearchCondition = _isSearchCondition;
var testIsCondition = caseExpression.Operand == null;
_isSearchCondition = false;
var operand = (SqlExpression)Visit(caseExpression.Operand);
var whenClauses = new List <CaseWhenClause>();
foreach (var whenClause in caseExpression.WhenClauses)
{
_isSearchCondition = testIsCondition;
var test = (SqlExpression)Visit(whenClause.Test);
_isSearchCondition = false;
var result = (SqlExpression)Visit(whenClause.Result);
whenClauses.Add(new CaseWhenClause(test, result));
}
_isSearchCondition = false;
var elseResult = (SqlExpression)Visit(caseExpression.ElseResult);
_isSearchCondition = parentSearchCondition;
return(ApplyConversion(caseExpression.Update(operand, whenClauses, elseResult), condition: false));
}
protected override Expression VisitCase(CaseExpression caseExpression)
{
Check.NotNull(caseExpression, nameof(caseExpression));
_isNullable = false;
// if there is no 'else' there is a possibility of null, when none of the conditions are met
// otherwise the result is nullable if any of the WhenClause results OR ElseResult is nullable
var isNullable = caseExpression.ElseResult == null;
var canOptimize = _canOptimize;
var testIsCondition = caseExpression.Operand == null;
_canOptimize = false;
var newOperand = (SqlExpression)Visit(caseExpression.Operand);
var newWhenClauses = new List <CaseWhenClause>();
foreach (var whenClause in caseExpression.WhenClauses)
{
_canOptimize = testIsCondition;
var newTest = (SqlExpression)Visit(whenClause.Test);
_canOptimize = false;
_isNullable = false;
var newResult = (SqlExpression)Visit(whenClause.Result);
isNullable |= _isNullable;
newWhenClauses.Add(new CaseWhenClause(newTest, newResult));
}
_canOptimize = false;
var newElseResult = (SqlExpression)Visit(caseExpression.ElseResult);
_isNullable |= isNullable;
_canOptimize = canOptimize;
return(caseExpression.Update(newOperand, newWhenClauses, newElseResult));
}
protected override Expression VisitCase(CaseExpression caseExpression)
{
Check.NotNull(caseExpression, nameof(caseExpression));
var parentOptimize = _optimize;
var testIsCondition = caseExpression.Operand == null;
_optimize = false;
var operand = (SqlExpression)Visit(caseExpression.Operand);
var whenClauses = new List <CaseWhenClause>();
foreach (var whenClause in caseExpression.WhenClauses)
{
_optimize = testIsCondition;
var test = (SqlExpression)Visit(whenClause.Test);
_optimize = false;
var result = (SqlExpression)Visit(whenClause.Result);
whenClauses.Add(new CaseWhenClause(test, result));
}
_optimize = false;
var elseResult = (SqlExpression)Visit(caseExpression.ElseResult);
_optimize = parentOptimize;
return(ApplyConversion(caseExpression.Update(operand, whenClauses, elseResult), condition: false));
}
private SqlExpression ApplyTypeMappingOnCase(
CaseExpression caseExpression, RelationalTypeMapping typeMapping)
{
var whenClauses = new List<CaseWhenClause>();
foreach (var caseWhenClause in caseExpression.WhenClauses)
{
whenClauses.Add(
new CaseWhenClause(
caseWhenClause.Test,
ApplyTypeMapping(caseWhenClause.Result, typeMapping)));
}
var elseResult = ApplyTypeMapping(caseExpression.ElseResult, typeMapping);
return caseExpression.Update(caseExpression.Operand, whenClauses, elseResult);
}
private CaseExpression VisitCaseExpression(CaseExpression caseExpression)
{
// if there is no 'else' there is a possibility of null, when none of the conditions are met
// otherwise the result is nullable if any of the WhenClause results OR ElseResult is nullable
var isNullable = caseExpression.ElseResult == null;
var newOperand = (SqlExpression)Visit(caseExpression.Operand);
var newWhenClauses = new List <CaseWhenClause>();
foreach (var whenClause in caseExpression.WhenClauses)
{
var newTest = (SqlExpression)Visit(whenClause.Test);
var newResult = (SqlExpression)Visit(whenClause.Result);
isNullable |= _isNullable;
newWhenClauses.Add(new CaseWhenClause(newTest, newResult));
}
var newElseResult = (SqlExpression)Visit(caseExpression.ElseResult);
_isNullable |= isNullable;
return(caseExpression.Update(newOperand, newWhenClauses, newElseResult));
}
protected override Expression VisitCase(CaseExpression x)
{
return(x?.Update(x.Operand.VisitNode(this), x.WhenClauses.ToList(), x.ElseResult.VisitNode(this)));
}
