#查询某个库所有表
select * from information_schema.TABLES
where table_schema = '数据库'
#查询某个库所有表的字段
select * from information_schema.COLUMNS
where table_schema = '数据库'
#查询所有表的注释和字段注释
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'
ORDER BY
a.table_name