SQL语句优化-php教程

在两张表里搜寻关键字,把符合关键字所对应的id查询出来

$keyword = "XX";       //关键字$sql1= "select id from table1 where title like "%$keyword%";$result1 = $this->db->getAll($sql1);     //sql执行后返回的id数组foreach($result1a as $k=>$v){                 $result1[$k]['flat'] = 1;           //给一个标识, 让我知道这是从table1里查出来的}$sql2= "select id from table2 where title like "%$keyword%";$result2 = $this->db->getAll($sql2);foreach($result2a as $k=>$v){                $result2[$k]['flat'] = 2;} $result = array_merge_recursive($result1, $result2);

回复讨论(解决方案)

遇到什么问题？？

1、你的$result1a，$result1b都是空，循环没什么意义，估计打错了
2、循环体貌似也没什么用

请把问题描述清楚

遇到什么问题？？

1、你的$result1a，$result1b都是空，循环没什么意义，估计打错了
2、循环体貌似也没什么用

请把问题描述清楚

result1a ->result1，
result2a ->result2，

将sql1 和 sql2 合成一句sql 分别给与标志
相当于执行sql返回下面类型
array(
array("id" => 4,"flat" => 1 ),
array( "id" => 7, "flat" => 1),
array( "id" => 4,"flat" => 2)
);

$keyword = "XX";       //关键字 $sql1= "select id from table1 where title like "%$keyword%";$result1 = $this->db->getAll($sql1);     //sql执行后返回的id数组foreach($result1 as $k=>$v){                 $result1[$k]['flat'] = 1;           //给一个标识, 让我知道这是从table1里查出来的} $sql2= "select id from table2 where title like "%$keyword%";$result2 = $this->db->getAll($sql2);foreach($result2 as $k=>$v){                $result2[$k]['flat'] = 2;}  $result = array_merge_recursive($result1, $result2);

$sql1= "select id,1 as flat from table1 where title like '%$keyword%' union all select id,2 as flat from table2 where title like '%$keyword%'";

这样执行一次查询就行了，下面的合并数组都可以免了。