管理表

/*删除表*/

DROP TABLE t_year;

SELECT * FROM t_student;

/*复制表*/

CREATE TABLE t_copyStudent SELECT * FROM t_student;

SELECT * FROM t_copyStudent WHERE 1=0;

/*值复制表结构，不复制表的内容*/

CREATE TABLE t_cpoyStudent2 SELECT * FROM t_student

WHERE 1=0;

SELECT * FROM t_cpoyStudent2;

CREATE TABLE t_cpoy3 LIKE t_student;

SELECT * FROM t_cpoy3;

/*修改表*/

SELECT *FROM t_student;

/*增加一列数据*/

ALTER TABLE t_student ADD phone BIGINT;

/*删除一列数据 column列*/

ALTER TABLE t_student DROP COLUMN phone;

/*修改列的名称*/

ALTER TABLE t_student CHANGE COLUMN phonenum phonenumber BIGINT;

ALTER TABLE t_student CHANGE COLUMN phonenumber phonenum BIGINT;

/*修改列的数据类型*/

ALTER TABLE t_student CHANGE phonenumber phonenumber BIGINT;

ALTER TABLE t_student MODIFY phonenumber VARCHAR(100);

/*修改表名*/

ALTER TABLE t_student RENAME t_stu;

SELECT * FROM t_stu;

/*创建索引*/

CREATE INDEX nameIndex ON t_stu(s_name);

SELECT * FROM t_stu WHERE s_name="houyuan";

SELECT * FROM t_stu WHERE s_name="%yuan";#索引不会起作用

SELECT * FROM t_stu WHERE s_name="hou%"

/*删除索引*/

ALTER TABLE t_stu DROP INDEX nameIndex;