sql中where条件后的case when 用法

 

select  familyreg=case when address2='' then substring(address1,1,2) else substring(address2,1,2) end from comperson

select * from comperson where familyreg=(case when address2='' then substring(address1,1,2) else substring(address2,1,2) end )

select personID,familyreg,address2,address1 from comperson where familyreg like '%'+(case when address2='' then substring(address1,1,2) else substring(address2,1,2) end )+'%'

 

转自：http://blog.163.com/wll_009/blog/static/1173731172010834759382/