ORA-01427: 單行子查詢返回多個行
sql語句如下：
select h.operator,
to_char(h.operate_tm, 'yyyy-mm-dd hh24:mi:ss') operate_tm,
(select t.res_label name
from sysmngdba.res@msp t
where t.id = h.system_id) system_id,
(select t.res_label name
from sysmngdba.res@msp t
where t.id = h.module_id) module_id,
(select index_value
from int_sys_param
where index_type = 'operateType'
and index_code = h.operate_type) operate_type,
h.operate_page,
h.tab_nm,
DECODE(h.status, '0', '??', '1', '??', '2', '???????????') status,
DECODE(h.sensitive_Id, '1', '????', '2', '??', '3', '??') sensitive_Id,
h.ip_address,
h.note,
h.session_id,
h.transaction_id,
h.operator || ',' || nvl(h.operate_page, ' ') || ',' ||
nvl(h.session_id, 0) || ',' || nvl(h.transaction_id, 0)
from (select a.operator,
a.operate_tm,
a.system_id,
a.module_id,
a.operate_type,
a.operate_page,
a.tab_nm,
a.status,
a.sensitive_Id,
a.ip_address,
a.note,
a.session_id,
a.transaction_id
from process_log a
union all
select b.operator,
b.operate_tm,
b.system_id,
b.module_id,
b.operate_type,
b.operate_page,
b.tab_nm,
b.status,
b.sensitive_Id,
b.ip_address,
b.note,
b.session_id,
b.transaction_id
from iigsmdba.parameter_log b) h
where 1 = 1
and operate_tm >=
to_date('2015-03-06 00:00:00', 'yyyy-mm-dd hh24:mi:ss')
and operate_tm <=
to_date('2015-03-09 23:59:59', 'yyyy-mm-dd hh24:mi:ss')
解決辦法：
首先要確認是哪個子查詢引起的，以上面的sql為例
在這三條在子查詢中加入rownum<2, 限制返回一行數據。可以成功查詢。
select t.res_label name
from sysmngdba.res@msp t
where t.id = h.system_id and rownum<2) system_id,
(select t.res_label name
from sysmngdba.res@msp t
where t.id = h.module_id and rownum<2) module_id,
(select index_value
from int_sys_param
where index_type = 'operateType'
and index_code = h.operate_type and rownum<2) operate_type,
然后依次去掉 rownum < 2，看看具體是哪一條引起的。
最后排查是下面這條語句存在多條數據：
select index_value
from int_sys_param
where index_type = 'operateType'
and index_code = h.operate_type