?

执行嵌套更新，遇到错误You can't specify target table 'scar' for update in FROM clause

update scar

set main_resource_id=(

? select id from ?scar2

? where 1=1 and scar2.subject_templates_activity_resource_id=(

? ? select main_resource_id from ?star?

? ? where 1=1 and star.id=scar.subject_templates_activity_resource_id

? ? )

? )

where 1=1?

and scar.group_type=2

?

查询发现mysql不支持嵌套更新，只好改用表连接来进行更新

?

update ?scar

inner join scar2

inner join ?star?

set scar.main_resource_id=scar2.id

where 1=1

and scar2.subject_templates_activity_resource_id=star.main_resource_id

and star.id=scar.subject_templates_activity_resource_id

and scar.group_type=2

and scar.activity_id in (select id from rsc_subject_cases_activity sca where sca.subject_cases_id='1')

?

感觉这样性能会查一些，不过等后续修改的时候再查执行计划看看