ORA-02324: more than one column in the SELECT list of THE subquery ORACLE 报错 故障修复 远程处理

文档解释

ORA-02324: more than one column in the SELECT list of THE subquery

Cause: More than one column was selected in the THE subquery.

Action: Specify only one column in the SELECT list of the THE subquery and retry the operation.

ORA-02324错误，又称为“多余的列超出了SELECT列表中的子查询”。当子查询的select列表中包含一个或多个列时，会发生此错误。

官方解释

“more than one column specified in the select list of the subquery”

常见案例

sql> Select a.id,b.name

4 from tab_a a

5 where a.id not in (Select id1, name2 from tab_b);

错误报告：

ORA-02324: more than one column in the SELECT list of the subquery

正常处理方法及步骤

1. 首先检查子查询中的SELECT，确保只有一列被指定。

2. 如果select列表中需要获取多列，可以使用以下方法：

a. 使用连接来替代子查询，如：

SELECT a.id, b.name

FROM tab_a a

LEFT JOIN tab_b b

ON a.id1 = b.id1

WHERE b.name2 IS NULL;

b. 使用case语句

SELECT a.id,

CASE WHEN (SELECT b.name2 from tab_b b where b.id1 = a.id1)

IS NOT NULL

THEN (SELECT b.name2 from tab_b b where b.id1 = a.id1)

ELSE b.name END

FROM tab_a a;