这个查询有什么错误？

Question

$query = "select (select count(a.serial_no) from tra2 a where a.model_no = ".$id." and a.flag = cast(3 as character varying) + (select count(a.serial_no) from stk a where a.model_no = ".$id." and a.trans_id is  NULL)as qty)";
    $result = $this->db->query($query);
    return $result->result();

当我运行查询时

ERROR:  syntax error at or near "as"
LINE 1: ...ck a where a.model_no = K258 and a.trans_id is  NULL)as qty)

Answer 1

在''条款中添加WHERE（引号）。我猜数据类型为VARCHAR，因此您必须在查询中使用引号

喜欢这个 .... WHERE a.model_no = '" . $id . "' AND ...

Answer 2

任务结束必须是：

 ...a.trans_id is  NULL)) as qty"

目前你有一些这样的

select (select 1 + 2 as qty)

但你想要

select (select 1 + 2) as qty