This is common operation of mysql table.

mysql_operate.md

• modify column type:

alter table formula_details modify val1 decimal(15,10);

• change column name:

ALTER TABLE user CHANGE name newname CHAR(32) NOT NULL DEFAULT '123';

• add default value:

ALTER TABLE user ALTER age SET DEFAUTL 18;

• delete default value:

ALTER TABLE user ALTER age DROP DEFAULT;

• add column:

ALTER TABLE `merchant_agings` ADD `aging_type` smallint DEFAULT 1 NOT NULL COMMENT '时效类型 1:小时 2:天';

• add comment of table:

ALTER TABLE `merchant_agings` COMMENT '商家时效';

• create table:

CREATE TABLE `merchant_products` (
    `id` INT(11) AUTO_INCREMENT PRIMARY KEY,
    `merchant_id` INT(11) NOT NULL,
    `merchant_name` VARCHAR(255) NOT NULL,
    `product_name` VARCHAR(255) NOT NULL,
    `created_at` DATETIME NOT NULL,
    `updated_at` DATETIME NOT NULL
)  ENGINE=INNODB;

• insert value:

INSERT INTO schema_migrations (version) VALUES ('20171027020112');

• grant tom with the password of 1234576 to access the users table:

grant all privileges on users.* to 'tom'@'%' identified by '123456';