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//
// Like.cs
//
// Author:
// Juraj Skripsky (juraj@hotfeet.ch)
//
// (C) 2004 HotFeet GmbH (http://www.hotfeet.ch)
//
//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
using System.Data;
namespace Mono.Data.SqlExpressions {
internal class Like : UnaryExpression {
readonly IExpression _pattern;
public Like (IExpression e, IExpression pattern) : base (e)
{
_pattern = pattern;
}
public override bool Equals(object obj)
{
if (!base.Equals (obj))
return false;
if (!(obj is Like))
return false;
Like other = (Like) obj;
return _pattern.Equals (other._pattern);
}
public override int GetHashCode()
{
return _pattern.GetHashCode () ^ base.GetHashCode ();
}
override public object Eval (DataRow row)
{
object o = expr.Eval (row);
if (o == null || o == DBNull.Value)
return false;
string str = (string)o;
bool openStart, openEnd;
string pattern = (string) _pattern.Eval (row);
string original = pattern;
int len = pattern.Length;
openStart = (pattern [0] == '*' || pattern [0] == '%');
openEnd = (pattern [len - 1] == '*' || pattern [len - 1] == '%');
pattern = pattern.Trim ('*', '%');
pattern = pattern.Replace ("[*]", "[[0]]");
pattern = pattern.Replace ("[%]", "[[1]]");
if (pattern.IndexOf ('*') != -1 || pattern.IndexOf ('%') != -1)
throw new EvaluateException (String.Format ("Pattern '{0}' is invalid.", original));
pattern = pattern.Replace ("[[0]]", "*");
pattern = pattern.Replace ("[[1]]", "%");
pattern = pattern.Replace ("[[]", "[");
pattern = pattern.Replace ("[]]", "]");
if (!row.Table.CaseSensitive) {
str = str.ToLower();
pattern = pattern.ToLower();
}
int idx = str.IndexOf (pattern);
if (idx == -1)
return false;
return (idx == 0 || openStart) && (idx + pattern.Length == str.Length || openEnd);
}
override public bool EvalBoolean (DataRow row)
{
return (bool)Eval (row);
}
}
}