STR_TO_DATE(final.time, '%Y-%m-%d %H:%i:%S') AS time
select *,if(sva=1,"男","女") as ssva from taname
作為表達(dá)式的if也可以用CASE when來實(shí)現(xiàn)：
select CASE sva WHEN 1 THEN '男' ELSE '女' END as ssva from taname
substr(str,pos,len);//str:字符串戈抄，pos：起始位置，len：截?cái)嚅L(zhǎng)度
CONCAT(str1,str2,…)
substring_index(str,delim,count) str:要處理的字符串 delim:分隔符 count:計(jì)數(shù)
group_concat([DISTINCT] 要連接的字段 [Order BY ASC/DESC 排序字段] [Separator '分隔符'])
IF(a=0, a, b) AS id
locate(subStr,string) ：函數(shù)返回subStr在string中出現(xiàn)的位置
