MySQL随机查询4条记录
SELECT * from vat_subject sb
WHERE stage_id=1 and course=0
ORDER BY RAND() LIMIT 0,4
ORDER BY RAND() :代表随机
LIMIT 0,4 :查询4条数据
随机查询4条
测试结果1:

测试结果2:

SELECT * from vat_subject sb
WHERE stage_id=1 and course=0
ORDER BY RAND() LIMIT 0,4
ORDER BY RAND() :代表随机
LIMIT 0,4 :查询4条数据
随机查询4条
测试结果1:

测试结果2:
