mysql 两表排重

[wwwksakjsoa]

两个表的数据大概都在100W 表A 和表B 排重要根据3个字段 a,b,c这三个字段都相同才排重a表中的

[wwwwb]

贴建表及插入记录的SQL，及要求结果出来看看

[jiaweiqq123]

python:
SELECT1="select a,b,c from A";
cur.execute(SELECT1)
result1=cur.fetchall()
SELECT2="select * from B where a=%s and b=%s and c=%c"
cur.execut(SELECT2,result1)
result2=cur.execute(SELECT2)
if result2 != ():
DELETE="delete * from B where a=%s and b=%s and c=%c"
cur.execute(DELETE,result1)

[ACMAIN_CHM]

delete from a where exists (select 1 from b where a=a.a and b=a.b and c=a.c);

或者

delete a from a inner join b on a.a=b.a and a.b=b.b and a.c=b.c;

不过需要有索引(a,b,c)