SELECT `招聘岗位`,COUNT(`招聘岗位`) AS '统计'FROM `招聘信息` GROUP BY `招聘岗位` 

SELECT `招聘单位`,COUNT(`招聘单位`) AS '统计'FROM `招聘信息` GROUP BY `招聘单位`

SELECT `招聘单位`, ROUND(AVG(REPLACE(SUBSTRING(`薪资区间`,1,2),'k',''))*1000,2) AS '平均最低薪资',ROUND(AVG(REPLACE(REPLACE(SUBSTRING(`薪资区间`,4,3),'k',''), '-',''))*1000,2) AS '平均最高薪资' FROM `招聘信息` GROUP BY `招聘单位`;