Mysql 查看表注释或字段注释

SELECT
table_name 表名,
table_comment 表说明
FROM
information_schema.TABLES
WHERE
table_schema = '数据库名'
ORDER BY
table_name

SELECT
a.table_name 表名,
a.table_comment 表说明,
b.COLUMN_NAME 字段名,
b.column_comment 字段说明,
b.column_type 字段类型,
b.column_key 约束
FROM
information_schema. TABLES a
LEFT JOIN information_schema. COLUMNS b ON a.table_name = b.TABLE_NAME
WHERE
a.table_schema = '数据库名'
ORDER BY
a.table_name

select 
COLUMN_NAME 字段名,
column_comment 字段说明,
column_type 字段类型,
column_key 约束 from information_schema.columns 
where table_schema = '数据库名'
and table_name = '表名' ;

show full columns from 表名;

show create table 表名;

create table t_user(
	ID INT(19) primary key auto_increment  comment '主键',
	NAME VARCHAR(300) comment '姓名',
	CREATE_TIME date comment '创建时间'
)comment  = '用户信息表';

alter table t_user comment  = '修改后的表注释信息(用户信息表)';

alter table t_user modify column id int comment '主键ID';

# 拼接删除索引的语法(排除主键索引)
SELECT CONCAT('ALTER TABLE ',i.TABLE_NAME,' DROP INDEX ',i.INDEX_NAME,' ;') 
FROM INFORMATION_SCHEMA.STATISTICS i
WHERE TABLE_SCHEMA = '库名' AND i.INDEX_NAME <> 'PRIMARY';

# 拼接删除索引的语法(排除主键索引)
SELECT CONCAT('ALTER TABLE ',i.TABLE_NAME,' DROP INDEX ',i.INDEX_NAME,' ;') 
FROM INFORMATION_SCHEMA.STATISTICS i
WHERE TABLE_SCHEMA = 'xhkj_ques_0919' AND TABLE_NAME='t_question_bak' AND i.INDEX_NAME <> 'PRIMARY';