php - 如果 table1 中存在，则从 table2 中删除

Question

我有 2 张桌子。table1 有 200 万条记录，table2 有 1100 万条记录我想从 table2 中删除 table1 我如何在 MySQL 中执行此操作，对于这个数据计数需要多少？谢谢你。

Answer 1

听起来您想删除表 2 中与表 1 中的记录匹配的所有记录。如果是这样，您可以使用子查询。我不确定这对您拥有的记录数量有多有效，但以下应该有效：

DELETE FROM table2 where table2.phonenumber IN (select phonenumber from table1);

Answer 2

SELECT Table2.* FROM Table2   JOIN Table1 ON Table2.phone = Table1.phone WHERE Table2.phone is not null

DELETE Table2.* FROM Table2   JOIN Table1 ON Table2.phone = Table1.phone WHERE Table2.phone is not null

Answer 3

Delete from table2
where number in (Select number from table1)

Answer 4

尝试加入，然后从加入中删除

SELECT tbl1.MyId FROM table1 tbl1
JOIN table2 on tbl1.phonenumber = tb2.phonenumber

然后从中删除

如

DELETE FROM Table2 WHERE MyID IN
(SELECT tbl1.MyId FROM table1 tbl1
JOIN table2 on tbl1.phonenumber = tb2.phonenumber)

这是sql代码，不确定mysql有什么变化

祝你好运！