Database component Hxj.data (32) Whereclipbuilder

Whereclipbuilder is a new class in version 1.7.2 that is used to create whereclip.

The previous version Whereclip was created as follows:

WhereClip where = WhereClip.All;
where = where.And(Products._.ProductName.Contain("apple"));
where = where.And(Products._.UnitPrice > 1);
where = where.Or(Products._.CategoryID == 2);每增加一个条件都是生成一个新的WhereClip。

Use Whereclipbuilder as follows:

WhereClipBuilder wherebuilder = new WhereClipBuilder();
wherebuilder.And(Products._.ProductName.Contain("apple"));
wherebuilder.And(Products._.UnitPrice > 1);
wherebuilder.Or(Products._.CategoryID == 2);

Whereclipbuilder is to create new instances without adding conditions, thus reusing and saving resources.

Specific use:

Northwind.From<Products>()
.Where(wherebuilder.ToWhereClip())
.ToList();

Generated sql:

Text: SELECT * FROM [Products]
WHERE (((([Products].[ProductName] LIKE @jtioerxooyxzyvsj) AND ([Products].[UnitPrice] > @txdupnwvhfznviqj))
OR ([Products].[CategoryID] = @iqgkjykstppcrqsq)))
Parameters:
@jtioerxooyxzyvsj[String] = %apple%
@txdupnwvhfznviqj[Int32] = 1
@iqgkjykstppcrqsq[Int32] = 2

Download: http://www.cnblogs.com/huxj/archive/2009/11/21/1607791.html