SELECT * FROM information_schema.COLUMNS;
SELECT
t.TABLE_SCHEMA AS 库名,
t.TABLE_NAME AS 表名,
t.COLUMN_NAME AS 字段名,
t.COLUMN_TYPE AS 数据类型,
CASE IFNULL(t.COLUMN_DEFAULT,'Null')
WHEN '' THEN '空字符串'
WHEN 'Null' THEN 'NULL'
ELSE t.COLUMN_DEFAULT END AS 默认值,
CASE t.IS_NULLABLE WHEN 'YES' THEN '是' ELSE '否' END AS 是否允许为空,
t.COLUMN_COMMENT AS 字段说明
FROM information_schema.COLUMNS t
WHERE t.TABLE_SCHEMA='boshi_cf' AND t.TABLE_NAME='a_active_code'
https://zhuanlan.zhihu.com/p/129228812
https://blog.csdn.net/sinat_40770656/article/details/91194323