private IQueryable <T> SmartWhereBinaryExpression(Expression <Func <T, bool> > predicate)
{
// parse the body
BinaryExpression ex = (BinaryExpression)predicate.Body;
if (ex.NodeType != ExpressionType.Equal)
{
return(null);
}
// get left value
MemberExpression left = (MemberExpression)ex.Left;
if (left.Expression.NodeType != ExpressionType.Parameter)
{
return(null);
}
string leftName = left.Member.Name;
// check right value
if (ex.Right.NodeType == ExpressionType.MemberAccess && ((MemberExpression)ex.Right).Expression.NodeType == ExpressionType.Parameter)
{
return(null);
}
object value = Expression.Lambda(ex.Right).Compile().DynamicInvoke();
if (value is Boolean)
{
value = (bool)value ? 1 : 0;
}
if (!(value is Int32) && !(value is String))
{
return(null);
}
// check if mapping supports SQL compare
var mappingList = mapping.Where(x => x.PropertyName == leftName);
if (mappingList.Count() == 0)
{
return(null);
}
SQLFieldMapping thisMapping = mappingList.First();
if (!Attribute.IsDefined(thisMapping.Reader.Method, typeof(AllowSQLCompareAttribute)))
{
return(null);
}
// build SQL
AllowSQLCompareAttribute attr = (AllowSQLCompareAttribute)Attribute.GetCustomAttribute(thisMapping.Reader.Method, typeof(AllowSQLCompareAttribute));
// create smart where
whereItems.Add(new Tuple <string, object>(attr.GetSQLCondition(thisMapping), value));
return(this);
}
private IQueryable <T> SmartWhereMethodCall(Expression <Func <T, bool> > predicate)
{
MethodCallExpression mce = predicate.Body as MethodCallExpression;
// verify some preconditions
if (mce.Method.Name != "Contains")
{
return(null);
}
if (mce.Arguments.Count != 1 || mce.Arguments[0].NodeType != ExpressionType.MemberAccess)
{
return(null);
}
if (mce.Object.NodeType != ExpressionType.MemberAccess)
{
return(null);
}
// get value
object value = Expression.Lambda(mce.Arguments[0]).Compile().DynamicInvoke();
if (!(value is Int32) && !(value is String))
{
return(null);
}
// check mapping
string field = (mce.Object as MemberExpression).Member.Name;
var mappingList = mapping.Where(x => x.PropertyName == field);
if (mappingList.Count() == 0)
{
return(null);
}
SQLFieldMapping thisMapping = mappingList.First();
if (!Attribute.IsDefined(thisMapping.Reader.Method, typeof(AllowSQLCompareAttribute)))
{
return(null);
}
// build SQL
AllowSQLCompareAttribute attr = (AllowSQLCompareAttribute)Attribute.GetCustomAttribute(thisMapping.Reader.Method, typeof(AllowSQLCompareAttribute));
whereItems.Add(new Tuple <string, object>(attr.GetSQLCondition(thisMapping), value));
return(this);
}
