mysql的那些熊事

//查询test_main_lirun表中a开头的字段名
SELECT COLUMN_NAME FROM information_schema.COLUMNS where table_name = 'test_main_lirun' and COLUMN_NAME like 'a%'

//用sum相加之后小数点后有很多位的问题,(5,1)是一共五位数,包括小数点后一位
select CAST(SUM(fraction) AS DECIMAL (5, 1)) as sum from ranking_student_curriculum

//两个时间相差多少分钟

SELECT * ,TIMESTAMPDIFF ( MINUTE, create_at,now() )  from order_form 

//根据两地的坐标计算距离

select *, cast(st_distance_sphere(POINT(lon, lat), POINT(117.11297, 36.66167)) / 1000 as DECIMAL(5, 1)) as distance from building