关于两个表对应的不匹配查询的正确语句为()
A. SELECT[ccode]FROM[GL_accsum]where not exists(SELECT*FROM[code]group by ccode having[ccode]=[GL_accsum].[ccode])
B. SELECT[ccode]FROM[GL_accsum]v where ccode not in(SELECTccodeFROM[code] where[ccode]=[v].[ccode])
C. select ccode from[GL_accsum]a left join code bon [ccode]=[b].[ccode] where ccode is null
D. select ccode codes from[GL_accsum]a join code bon [ccode]=[b].[ccode] where ccode is null