MySql 查詢表有多少列

-- 查詢一個表共有多少列數
select count(*) 
from information_schema.COLUMNS 
where TABLE_SCHEMA='庫名' and table_name='表名' 

-- 查詢某個數據庫中某個表的所有列名
SELECT COLUMN_NAME FROM information_schema.COLUMNS
WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'tb_name';

-- 查詢某個數據庫中某個表的所有列名,並用逗號連接
SELECT GROUP_CONCAT(COLUMN_NAME SEPARATOR ",") FROM information_schema.COLUMNS 
WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'tb_name';