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mysql数据库 时间：2024-12-24 19:11:56
作者：文/会员上传
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#案例：选中city在多伦多工作的员工SELECTlast_name,job_id,e.department_id,department_nameFROMemployees AS e,departments AS d,locations AS lWHEREe.`department_id`=d.
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#案例：选中city在多伦多工作的员工
SELECTlast_name,job_id,e.department_id,department_nameFROMemployees AS e,departments AS d,locations AS lWHEREe.`department_id`=d.`department_id`ANDd.`location_id`=l.`location_id`ANDl.city='Toronto'#案例；查询每个国家下的部门个数大于2的国家编号
SELECTcountry_id ,COUNT(*)FROMlocations AS l,departments AS dWHEREl.`location_id`=d.`location_id`GROUP BYcountry_idHAVINGCOUNT(*) >2;11-20
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