php实现搜索功能代码

/******
**一个简单的搜索
*****/
//将搜索语句加到最开始的查询语句里面；从而实现了代码的精简
$news_sql = "SELECT * from books where 1=1 ".$searchAddSql." order by book_number ";
// $searchAddSql最开始是为空的，如果用户输入了搜索条件，$searchAddSql
就会变成一个包涵查询语句的字符串：
//先判定用户是否输入了搜索条件
if(isset($_GET["searchText"]))
{
$searchText = $_GET["searchText"];
$searchAddSql = $searchAddSql." and (book_number like '%".$searchText."%' 
or book_name like '%".$searchText."%'
or book_sum like '%".$searchText."%'
or book_author like '%".$searchText."%')";
}
//最开始的$news_sql = "SELECT * from books where 1=1 ".$searchAddSql." order by book_number ";就会变成：
$news_sql="SELECT * from books where 1=1 and (book_number like '%中%'
or book_name like '%中%'
or book_sum like '%中%'
or book_author like '%中%' ) order by book_number"；
//相当于重置了查询语句，从而达到搜索的目地