题
我要更新表表明,一些行是别人的父母,所以我加了一个“的parentId”列表。以下查询查找所有的家长:
SELECT ca1.id, ca2.id
FROM contactassociations ca1
JOIN contactassociations ca2 ON (ca1.contactid = ca2.contactid)
where ca1.entitytable = 'EMPLOYER' AND
ca2.entitytable = 'CLIENT';
但是当我尝试去适应这种语法做了更新,这是行不通的:
UPDATE contactassociations ca1
SET ca1.parentid = ca2.id
JOIN contactassociations ca2 ON (ca1.contactid = ca2.contactid)
WHERE ca1.entitytable = 'EMPLOYER' AND ca2.entitytable = 'CLIENT';
我得到:
Error starting at line 6 in command:
UPDATE contactassociations ca1
SET ca1.parentid = ca2.id
JOIN contactassociations ca2 ON (ca1.contactid = ca2.contactid)
WHERE ca1.entitytable = 'EMPLOYER' AND ca2.entitytable = 'CLIENT'
Error at Command Line:7 Column:28
Error report:
SQL Error: ORA-00933: SQL command not properly ended
00933. 00000 - "SQL command not properly ended"
*Cause:
*Action:
注意,线7列28是 “SET” 行的末尾。
解决方案
Oracle不支持在JOIN
语句UPDATE
子句。
使用这样的:
MERGE
INTO contactassociations ca1
USING contactassociations ca2
ON (
ca1.contactid = ca2.contactid
AND ca1.entitytable = 'EMPLOYER'
AND ca2.entitytable = 'CLIENT'
)
WHEN MATCHED THEN
UPDATE
SET parentid = ca2.id
其他提示
我找到以下样式简单的阅读,但你需要在更新关键字,而不是表名后使用别名:
UPDATE ca1
SET ca1.parentid = ca2.id
FROM contactassociations ca1
LEFT JOIN contactassociations ca2 ON (ca1.contactid = ca2.contactid)
WHERE ca1.entitytable = 'EMPLOYER' AND ca2.entitytable = 'CLIENT'
-- Method #1
update emp set MANAGERNAME= mgr.EMPNAME
FROM SelfJoinTable emp , SelfJoinTable mgr where emp.MANAGERID = mgr.EMPID
-- Method #2
update emp
set MANAGERNAME= mgr.EMPNAME
FROM SelfJoinTable emp
LEFT OUTER JOIN SelfJoinTable mgr
ON emp.MANAGERID = mgr.EMPID
-- Method #3
update emp
set MANAGERNAME= mgr.EMPNAME
FROM SelfJoinTable emp
JOIN SelfJoinTable mgr
ON emp.MANAGERID = mgr.EMPID
-- Method #4
update emp
set MANAGERNAME= mgr.EMPNAME
FROM SelfJoinTable emp
inner JOIN SelfJoinTable mgr
ON emp.MANAGERID = mgr.EMPID
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