Oracle关联更新语法，T-SQL中的update...from

表关联更新语句：

场景：

表：

AM_APPROVE_LIST_LOG_SAMMY

AM_APPROVE_LIST_SAMMY

更新栏位：

EMP_ID, APPROVER_SEQUENCE, APPROVER_ID

关联栏位：

EMP_ID, APPROVER_ID

方法一：

UPDATE am_approve_list_log_sammy a

SET (a.emp_id, a.approver_sequence, a.approver_id) =

(SELECT b.emp_id, b.approver_sequence, b.approver_id

FROM am_approve_list_sammy b

WHERE b.emp_id = a.emp_id AND b.approver_id = a.approver_id)

WHERE EXISTS (SELECT 1

FROM am_approve_list_sammy c

WHERE c.emp_id = a.emp_id AND c.approver_id = a.approver_id)

方法二：(10g(含)以上版本才可以使用)

MERGE INTO gt$fm_form_field_import imp

USING fm_form_field fie

ON ( imp.field_name = fie.field_name

AND fie.form_kind = 'BQE.FORM.7'

AND fie.table_name = 'BQEFORM7')

WHEN MATCHED THEN

UPDATE

SET imp.description = fie.description,

imp.is_query = fie.is_query,

imp.is_default_value = fie.is_default_value,

imp.is_query_show = fie.is_query_show,

imp.is_form_show = fie.is_form_show,

imp.is_participant = fie.is_participant,

imp.is_mail_show = fie.is_mail_show