public static Expression MergeExpression(QueryExpression.Operations op, Expression left, Expression right)
{
try
{
switch (op)
{
case QueryExpression.Operations.Equal:
return(Expression.Equal(left, right));
case QueryExpression.Operations.GreaterThan:
return(Expression.GreaterThan(left, right));
case QueryExpression.Operations.GreaterThanOrEqual:
return(Expression.GreaterThanOrEqual(left, right));
case QueryExpression.Operations.LessThan:
return(Expression.LessThan(left, right));
case QueryExpression.Operations.LessThanOrEqual:
return(Expression.LessThanOrEqual(left, right));
case QueryExpression.Operations.NotEqual:
return(Expression.NotEqual(left, right));
case QueryExpression.Operations.IsChildFrom:
MethodInfo mInfo = right.Type.GetMethod("Contains");
return(Expression.Call(right, mInfo, left));
case QueryExpression.Operations.Like:
MethodInfo mInfoL = right.Type.GetMethod("Contains");
return(Expression.Call(right, mInfoL, left));
default:
throw new ArgumentException("parameter: op is not correct");
}
}
catch (Exception e)
{
throw e;
}
}
private QueryExpression GetQueryExpression(QueryExpressionInfo queryExpressionInfo)
{
if (queryExpressionInfo == null)
{
return(null);
}
QueryExpression qe = new QueryExpression();
qe.PropertyName = queryExpressionInfo.PropertyName;
qe.QueryType = queryExpressionInfo.QueryType;
qe.RelatedType = queryExpressionInfo.RelatedType == "And" ? QueryExpression.RelationType.And : QueryExpression.RelationType.Or;
QueryExpression.Operations op = QueryExpression.Operations.Equal;
if (queryExpressionInfo.PropertyName == QueryExpression.Operations.GreaterThan.ToString())
{
op = QueryExpression.Operations.GreaterThan;
}
else if (queryExpressionInfo.PropertyName == QueryExpression.Operations.GreaterThanOrEqual.ToString())
{
op = QueryExpression.Operations.GreaterThanOrEqual;
}
else if (queryExpressionInfo.PropertyName == QueryExpression.Operations.LessThan.ToString())
{
op = QueryExpression.Operations.LessThan;
}
else if (queryExpressionInfo.PropertyName == QueryExpression.Operations.LessThanOrEqual.ToString())
{
op = QueryExpression.Operations.LessThanOrEqual;
}
else if (queryExpressionInfo.PropertyName == QueryExpression.Operations.Like.ToString())
{
op = QueryExpression.Operations.Like;
}
qe.Operation = op;
qe.PropertyValue = queryExpressionInfo.PropertyValue;
qe.RelatedExpression = GetQueryExpression(queryExpressionInfo.RelatedExpression);
return(qe);
}