标签：io ar os sp for on div cti ad
Query the given URI, returning a Cursor over the result set.
For best performance, the caller should follow these guidelines:
selection parameter, so that queries that differ only by those values will be recognized as the same for caching purposes.| uri | The URI, using the content:// scheme, for the content to retrieve. |
|---|---|
| projection | A list of which columns to return. Passing null will return all columns, which is inefficient. |
| selection | A filter declaring which rows to return, formatted as an SQL WHERE clause (excluding the WHERE itself). Passing null will return all rows for the given URI. |
| selectionArgs | You may include ?s in selection, which will be replaced by the values from selectionArgs, in the order that they appear in the selection. The values will be bound as Strings. |
| sortOrder | How to order the rows, formatted as an SQL ORDER BY clause (excluding the ORDER BY itself). Passing null will use the default sort order, which may be unordered. |
上面是2.2版本的api写的。
解释一下：假如一条sql语句如下：
select ＊ from anyTable where var=‘const‘
那么anyTable就是uri，＊就是projection，selection是“var=?"，selectionArgs写成这样：new String[]{‘const‘｝
至于最后一个就简单了，就是排序方式。
标签：io ar os sp for on div cti ad
原文地址：http://my.oschina.net/liusicong/blog/348743
