标签:one col 默认 not unique mes signed 表名 member
-- 创建表
DROP TABLE IF EXISTS member; CREATE TABLE member( id int(11) PRIMARY KEY AUTO_INCREMENT, regName VARCHAR(10) DEFAULT NULL UNIQUE KEY, pwd VARCHAR(16) NOT NULL, mobilePhone CHAR(11), type TINYINT(1) DEFAULT 1, leaveAmount DOUBLE(18,2) DEFAULT 0.00, regTime TIMESTAMP DEFAULT CURRENT_TIMESTAMP() );
-- 1:新增表字段
ALTER TABLE member ADD regTime TIMESTAMP DEFAULT CURRENT_TIMESTAMP(); ALTER TABLE member ADD type TINYINT DEFAULT 1 AFTER mobilePhone; ALTER TABLE member ADD regTime TIMESTAMP DEFAULT CURRENT_TIMESTAMP(),ADD type TINYINT DEFAULT 1 AFTER mobilePhone;
-- 2:删除表字段
ALTER TABLE member DROP type; ALTER TABLE member DROP regTime,ADD type TINYINT DEFAULT 1 AFTER mobilePhone; ALTER TABLE member DROP type,DROP leaveAmount;
-- 3:修改表字段
-- type tinyint 默认是1
-- 将type int ,默认值为2
ALTER TABLE member MODIFY type INT UNSIGNED DEFAULT 2;
ALTER TABLE member MODIFY type TINYINT UNSIGNED DEFAULT 1 FIRST;
-- 修改默认值
ALTER TABLE member MODIFY type TINYINT UNSIGNED DEFAULT 2; ALTER TABLE member ALTER type SET DEFAULT 3; ALTER TABLE member ALTER type DROP DEFAULT;
-- 4:修改列名,字段名
ALTER TABLE member CHANGE COLUMN regTime createTime TIMESTAMP;
-- 5:修改表名
ALTER TABLE member RENAME member2;
RENAME TABLE member2 TO member;
-- 6:增加约束
ALTER TABLE member ADD PRIMARY KEY (id);
ALTER TABLE member ADD UNIQUE KEY (regName);
ALTER TABLE member ADD UNIQUE (regName);
ALTER TABLE loan ADD CONSTRAINT fk_id FOREIGN KEY(memberID) REFERENCES member(id);
ALTER TABLE member ALTER type SET DEFAULT 3;
-- 7:删除约束
ALTER TABLE member DROP PRIMARY KEY;
SHOW INDEXES FROM member;
ALTER TABLE member DROP INDEX regName;
SHOW CREATE TABLE loan;
-- loan_ibfk_1
ALTER TABLE loan DROP FOREIGN KEY loan_ibfk_1;
ALTER TABLE member ALTER type DROP DEFAULT
标签:one col 默认 not unique mes signed 表名 member
原文地址:https://www.cnblogs.com/zhaojingyu/p/9030580.html