ORA-01427：單行子查詢返回不止一行

Question

我的查詢如下：

SELECT DISTINCT * 
FROM (SELECT depts."ID", depts.arabic_description 
     FROM sng_v_org_unit_departments depts 
     INNER JOIN (SELECT "ID", arabic_description, ouh_id 
        FROM sng_v_org_unit_headers 
        START WITH "ID" = 
        (SELECT headid 
        FROM emppirmesion per 
        inner join empldabdetail empinfo 
          on per.emprecid = empinfo.recid 
        where lower(empinfo.shortname) = lower('ibmadmin') and 
         per.headid > 0 and 
         per.clasisymbolicname = 'SoHiring') 
        CONNECT BY PRIOR "ID" = ouh_id) heads 
     ON depts.ouh_id = heads."ID" 
     UNION 
     SELECT per.depid, depts.arabic_description 
     FROM emppirmesion per 
     inner join empldabdetail empinfo on per.emprecid = empinfo.recid 
     inner join sng_v_org_unit_departments depts on per.depid = depts."ID" 
     where lower(empinfo.shortname) = lower('ibmadmin') and 
      per.depid > 0 and 
      per.clasisymbolicname = 'SoHiring') 

我得到一個異常ORA-01427：單行子查詢返回不止一行如果儘管它們具有不同的headid值，但在這種情況下不應出現這種情況，請告知這種情況，我在emppirmesion中有多行具有相同的clasissymbolicname。

Answer 1

問題是START WITH預計單值和我的子查詢中返回多個值，所以我從改變了查詢：

START WITH "ID" = 
        (SELECT headid 
        FROM emppirmesion per 
        inner join empldabdetail empinfo 
          on per.emprecid = empinfo.recid 
        where lower(empinfo.shortname) = lower('ibmadmin') and 
         per.headid > 0 and 
         per.clasisymbolicname = 'SoHiring') 

到：

Where "ID" in 
        (SELECT headid 
        FROM emppirmesion per 
        inner join empldabdetail empinfo 
          on per.emprecid = empinfo.recid 
        where lower(empinfo.shortname) = lower('ibmadmin') and 
         per.headid > 0 and 
        per.clasisymbolicname = 'SoHiring') 

和它的工作原理精細。