一、insert(增)1、将一个表的某些字段重新建为一个表insert into `tbnameA`(a,b,c) select a,b,c from `tbnameB`二、delete(删)1、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录delete from tbname where peopleId in (select peopleId from tbname group by peopleId...【阅读全文】
一、insert(增)1、将一个表的某些字段重新建为一个表insert into `tbnameA`(a,b,c) select a,b,c from `tbnameB`二、delete(删)1、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录delete from tbname where peopleId in (select peopleId from tbname group by peopleId...【阅读全文】
创建一个多列索引:CREATE TABLE test ( id INT NOT NULL, last_name CHAR(30) NOT NULL, first_name CHAR(30) NOT NULL, PRIMARY KEY (id), INDEX name (last_name,first_...【阅读全文】
一、insert(增)1、将一个表的某些字段重新建为一个表insert into `tbnameA`(a,b,c) select a,b,c from `tbnameB`二、delete(删)1、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录delete from tbname where peopleId in (select peopleId from tbname group by peopleId...【阅读全文】
一、insert(增)1、将一个表的某些字段重新建为一个表insert into `tbnameA`(a,b,c) select a,b,c from `tbnameB`二、delete(删)1、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录delete from tbname where peopleId in (select peopleId from tbname group by peopleId...【阅读全文】
8.11.3.1 Using Symbolic LinksYou can move databases or tables from the database directory to other locations and replace them with symbolic links to the new locations. You might want to do this, for example, to move a database to a file syste...【阅读全文】