public override VfpExpression Visit(VfpOrExpression expression)
{
var list = OrComparisonGatherer.Gather(expression);
if (!list.Any())
{
return(base.Visit(expression));
}
var comparison = list.Select(x => new {
x.ExpressionKind,
LeftExpression = x.Left,
LeftDbConstantExpression = ConstantGatherer.Gather(x.Left).FirstOrDefault(),
RightExpression = x.Right,
RightDbPropertyExpression = PropertyGatherer.Gather(x.Right).FirstOrDefault(),
RightDbVariableReferenceExpression = VariableReferenceGatherer.Gather(x.Right).FirstOrDefault()
}).First();
if (comparison.ExpressionKind != VfpExpressionKind.Equals && comparison.ExpressionKind != VfpExpressionKind.NotEquals)
{
return(base.Visit(expression));
}
if (comparison.LeftDbConstantExpression == null || comparison.RightDbPropertyExpression == null || comparison.RightDbVariableReferenceExpression == null)
{
return(base.Visit(expression));
}
var expressions = list.Select(x => new {
x.ExpressionKind,
LeftExpression = x.Left,
LeftDbConstantExpression = ConstantGatherer.Gather(x.Left).FirstOrDefault(),
RightExpression = x.Right,
RightDbPropertyExpression = PropertyGatherer.Gather(x.Right).FirstOrDefault(),
RightDbVariableReferenceExpression = VariableReferenceGatherer.Gather(x.Right).FirstOrDefault()
})
.Where(x => x.LeftDbConstantExpression != null)
.Where(x => x.RightDbPropertyExpression != null)
.Where(x => x.RightDbVariableReferenceExpression != null)
.ToList();
if (list.Count != expressions.Count)
{
return(base.Visit(expression));
}
if (!expressions.All(x => x.LeftDbConstantExpression.ConstantKind == comparison.LeftDbConstantExpression.ConstantKind &&
x.LeftDbConstantExpression.ResultType == comparison.LeftDbConstantExpression.ResultType &&
x.RightDbPropertyExpression.Property == comparison.RightDbPropertyExpression.Property &&
x.RightDbVariableReferenceExpression.VariableName == comparison.RightDbVariableReferenceExpression.VariableName))
{
return(base.Visit(expression));
}
var inExpression = comparison.RightExpression.In(list.Select(x => x.Left).ToList().List());
return(base.Visit(inExpression));
}
public override VfpExpression Visit(VfpComparisonExpression expression)
{
// Check the left expression to see if it contains a property expression.
// Don't need to rewrite the comparison expression of the left side already contains a property expression.
if (PropertyGatherer.Gather(expression.Left).Any())
{
return(expression);
}
// Check the right expression to see if it has a property expression.
if (!PropertyGatherer.Gather(expression.Right).Any())
{
return(expression);
}
return(reverseExpression(expression));
}
public override VfpExpression Visit(VfpLikeExpression expression)
{
// Check the argument expression to see if it contains a property expression.
// Don't need to rewrite the expression if the left side already contains a property expression.
if (PropertyGatherer.Gather(expression.Argument).Any())
{
return(expression);
}
// Check the pattern expression to see if it has a property expression.
if (!PropertyGatherer.Gather(expression.Pattern).Any())
{
return(expression);
}
return(VfpExpressionBuilder.Like(expression.ResultType,
expression.Pattern,
expression.Argument,
expression.Escape));
}
