Introduction to three statement methods for joint modification of multiple tables in Oracle Database

Introduction to three statement methods for joint modification of multiple tables in Oracle Database

1. The most efficient

Merge into user_member_info

USING (select min (UP. created) as cre, min (up. shop_no) as shop_no, up. memberid as memberid

From user_platform_relation up,

(Select memberid as mid, min (created) as cre

From user_platform_relation

Group by memberid) um

Where up. created = um. crere and up. memberid = um. mid

Group by up. memberid) B

ON (a. id = B. memberid

)

When matched then update set a. created = B. cre, a. shop_no = B. shop_no, a. modified_time = sysdate

Where a. shop_no is null;

2. Efficiency

Update (select ui. userid as uiuid, oi. user_id as oiuid,

Ui. id as uimid, oi. memberid as oimid,

Oi. modified_time as oitime

From user_member_info ui, reserveorder_info oi

Where ui. brandid = oi. brandid and ui. mobile = oi. telphone)

Set oiuid = uiuid, oimid = uimid;

3. The worst Efficiency

UPDATE RETURN_FACTORYORDER r SET (r. XSBILLDATE, r. DQ) = (

SELECT f. saletime, f. bezei from rf f WHERE r. BILL = f. BILL

)