mysql判断

case:例

 

CASE  
      WHEN p.hd > 320 THEN '重大风险'
      WHEN p.hd >= 160 AND p.hd <= 320 THEN '较大风险'
      WHEN p.hd >= 70 AND p.hd <= 159 THEN '一般风险'
      ELSE '低风险' END AS fj

if

SELECT IF(1>2,2,3);

SELECT IF(1<2,'y','n');

SELECT IF(name('test','test1'),'n','y');