mysql查询所有表及字段的注释信息

查询information_schema.tables表，查询结果去掉4个系统库

SELECT
    t1.TABLE_SCHEMA 库名,
    t1.table_name 表名,
    t1.table_comment 表注释,
    t2.COLUMN_NAME 字段名,
    t2.column_comment 字段注释 
FROM
    information_schema.TABLES t1
    LEFT JOIN information_schema.COLUMNS t2 ON t1.table_name = t2.TABLE_NAME 
WHERE
    t1.table_schema NOT IN ( 'sys', 'mysql', 'information_schema', 'performance_schema' ) 
ORDER BY
    t1.TABLE_SCHEMA,
    t1.table_name