varchar VS char 查询
select a.prt_spec from server.testzmpdm.dbo.product a, mf_bom b where b.spc is null and a.prt_productcode=(cast(b.prd_no as char(500)))

报错:
Server: Msg 446, Level 16, State 9, Line 1
Cannot resolve collation conflict for equal to operation.

条件只为b.spc is null执行正常.

a.prt_productcode char(30)
b.prd_no varchar (30)


[解决办法]
try:
select a.prt_spec from server.testzmpdm.dbo.product a, mf_bom b where b.spc is null and a.prt_productcode=rtrim((cast(b.prd_no as char(500)))) Collate Chinese_PRC_CS_AS_KS_WS
[解决办法]
select databasepropertyex( '名 ', 'collation ')