mysql syntax summary

• Create a table

CREATE TABLE tb_device(
device_id INT PRIMARY KEY AUTO_INCREMENT COMMENT '主键（非空 + 唯一），自增长',
device_name VARCHAR(255),
device_num INT,
curr_vers VARCHAR(255),
issue_vers VARCHAR(255),
ecurr_vers VARCHAR(255),
eissue_vers VARCHAR(255),
down_time VARCHAR(255),
create_time VARCHAR(255)
);

• Delete table

DROP TABLE tb_device

• Modify table

#添加列
ALTER TABLE tb_device ADD test_column INT NOT NULL;

#删除列
ALTER TABLE tb_device DROP test_column;

#修改表
ALTER TABLE tb_device2 RENAME tb_device;

#修改列
ALTER TABLE tb_device CHANGE device_num device_number VARCHAR(255) NOT NULL DEFAULT 'default';

• Since query
• Left connection
• The right connection