2026/8/14 19:06:04 mysql篇章(启动)(select里面写count() 和 having里面写count() 的区别)以及查询语句的顺序
select里面写count() 和 having里面写count() 的区别sql --① count写在SELECTSELECT class_id, school, COUNT(*) AS wang_numFROM studentWHERE name LIKE 王%GROUP BY class_id, school;--② count写在HAVINGSELECT class_id, schoolFROM studentWHERE name LIKE 王%GROUP …