mysql left join对于索引不生效的问题
摘要：
SELECT t.val, m.username FROM test.tmp_table AS t LEFT JOIN cehome.uc_members AS m USE INDEX(`mobile`) ON t.val=m.mobile 上面的left join uc_members表的mobi 阅读全文
posted @ 2017-09-06 10:28 dongruiha 阅读(2369) 评论(0) 推荐(0) 编辑
