mysql导出表字段

SELECT 
    c.TABLE_NAME AS '表名',
    c.COLUMN_NAME AS "字段名称",
    c.DATA_TYPE AS "数据类型",
    c.CHARACTER_MAXIMUM_LENGTH AS "长度",
    CASE WHEN c.IS_NULLABLE = 'YES' THEN '是' ELSE '否' END AS "是否可为空",
    c.COLUMN_COMMENT AS "字段说明"
FROM 
    INFORMATION_SCHEMA.COLUMNS c
WHERE 
    c.TABLE_SCHEMA = 'jjapp'
ORDER BY 
    c.TABLE_NAME, c.COLUMN_NAME;