mysql数据库学习――3,表的创建,删除和变更_MySQL
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mysql数据库学习——3,表的创建,删除和变更
表创建create table mytbl(id int auto_increment not null,name char(10) not null,birth date not null,wight int,sex enum('f','m'));指定数据库引擎的表创建create table mytbl(id int auto_increment not null,name char(10) not null,birth date not null,wight int,sex enum('f','m'))engine=memory;创建临时表create temporary table mytbl(id int auto_increment not null,name char(10) not null,birth date not null,wight int,sex enum('f','m'));
复制数据表结构(也可以这样创建一个临时表作副本create temporary table tblnew like tblold)create table tblnew like tblold同时复制数据insert into tblnew select * from tblold从查询结果创建表create table tblnew select * from tblold
删除数据表
drop table tbl_namedrop table tbl_name ,tbl2_namedrop table if exists tbl_namedrop temporary table tbl_name
修改数据表
修改数据列的数据类型alter table mytbl modify i mediumint unsignedalter table mytbl chang i i mediumint unsigned修改数据列的数据类型和字符集alter table mytbl modify i mediumint character set ucs2修改数据表的存储引擎alter table mytbl engine=engine_name
重命名数据表alter table tbl_name rename to new_tbl_namerename talbe tbl_name to new_tbl_name重命名多个数据表 rename talbe tbl_name to new_tbl_name,t1 to t2 ,t3 to t4移动数据表到另一个数据库alter table db1.tbl_name rename to db2.new_tbl_namerename talbe db1.tbl_name to db2.new_tbl_name
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