MySQL表的维护和改造_MySQL

bitsCN.com

MySQL表的维护和改造

 

改变列的数据类型    

[sql] 

ALTER TABLE visitor MODIFY nam VARCHAR(30);  

 

追加新列

[sql] 

ALTER TABLE visitor ADD age INT;  

ALTER TABLE visitor ADD age INT FIRST;  

ALTER TABLE visitor ADD age INT AFTER nam;  

 

改变列的位置

[sql] 

ALTER TABLE visitor MODIFY age INT AFTER nam;  

 

改变列名 和 类型

[sql] 

ALTER TABLE visitor CHANGE birth birthday DATE;  

 

删除列

[sql] 

ALTER TABLE visitor DROP age;  

 

表的复制

[sql] 

CREATE TABLE customerH SELECT * FROM customer;  

CREATE TABLE customerG LIKE customer;  

INSERT INTO customerG SELECT * FROM customer;  

INSERT INTO tb1G(no) SELECT bang FROM tb1;  

 

表的删除

[sql] 

DROP TABLE IF EXISTS customerG;  

DROP TABLE customerG;  

 

bitsCN.com