Question

请给我建议，如何构建选择查询。我的表table包含字段type和obj_id。我想选择与下一个数组一致的所有记录：

$arr = array(
0 => array('type' => 1, 'obj_id' => 5),
1 => array('type' => 3, 'obj_id' => 15),
2 => array('type' => 4, 'obj_id' => 14),
3 => array('type' => 12, 'obj_id' => 17),
);

我想通过一个查询选择所需的行，是真的吗？像Smth一样

select * from `table` where type in (1,3,4,12) and obj_id in (5,15,14,17)

但是此查询还返回type = 3和obj_id = 14的记录，例如type = 1和obj_id = 17。附：主持人，请修改我的标题，我不知道如何描述我的问题。

update: array $arr could contain more than 500 elems.

Answer 1

据我所知，你不能使用in，但你必须回到这样的事情

select * from `table` where type=1 and obj_id=5 or type=3 and obj_id=15

Answer 2

如果我理解正确，您可以使用UNION或OR。使用UNIONs：

select * from `table` where type = 1 and obj_id = 5
UNION ALL
select * from `table` where type = 3 and obj_id = 15
UNION ALL
select * from `table` where type = 4 and obj_id = 14
UNION ALL
select * from `table` where type = 12 and obj_id = 17

如果您需要删除重复项，请从ALL移除UNION ALL。

使用OR：

select * from `table` 
 where (type = 1 and obj_id = 5)
    OR (type = 3 and obj_id = 15)
    OR (type = 4 and obj_id = 14)
    OR (type = 12 and obj_id = 17)

括号重要 - 它们表示需要满足所有内容。

我建议使用UNIONs - OR因性能不佳而臭名昭着。

Answer 3

$sql = 'select * from `table` where ';

foreach ($arr as $index => $conditions){
    $sql .= $or.' (';
    foreach($condicions as $key => $value){
       $sql .= $concat. "$key = $value";
       $concat = ' and ';
    }
    $sql .= ')';
    $or = ' or ';
}

应该形成$ sql as：

select * from table where 
  (type = 1 and obj_id = 5) or 
  (type = 3 and obj_id = 15) or 
  (type = 4 and obj_id = 14) or 
  (type = 12 and obj_id = 17);

Answer 4

如果条件数组变大，您可能想要创建一个索引临时表，在table (type, obj_id)上有一个复合索引并执行INNER JOIN。

通过一个查询选择多个记录

4 个答案: