SQL中AND、OR的优先级

• 当AND、OR运算符同时存在时,SQL语言认为AND优先级高于OR

  condition1
  OR   condition2 
  AND   condition3
  
  等价于
  
  condition1
  OR   （condition2 AND condition3）
  

  SELECT * FROM EMR_YZB  
  WHERE
   ( 
  	EMR_YZB.ZYH = 1131279) AND 
   	(EMR_YZB.YZQX = 0 and 0<3 and nvl(rjbrpb,0) <>1 Or 0 = 0 or EMR_YZB.YZQX = 2 and rjbrpb =1 
  ) 
           
  等价于
  SELECT * FROM EMR_YZB  
   WHERE 
   ( 
   	EMR_YZB.ZYH = 1131279) AND 
  	 ((EMR_YZB.YZQX = 0 and 0<3 and nvl(rjbrpb,0) <>1) Or (0 = 0 )or (EMR_YZB.YZQX = 2 and rjbrpb =1) 
  ) 
  

Reference

• AND、OR运算符的组合使用 https://blog.csdn.net/yixian918/article/details/24255003?utm_source=distribute.pc_relevant.none-task