Question

sql空值值转化为0

SELECT ES_Eval_Result AS Result,
(SELECT num
FROM (SELECT ES_Eval_Result, COUNT(ES_ID) AS num, ES_Stage
FROM ES_EvaluateStandard
WHERE (VP_ID = 28)
GROUP BY ES_Stage, ES_Eval_Result) AS es1
WHERE (ES_Eval_Result = es2.ES_Eval_Result) AND (ES_Stage = 0)) AS 概念策划阶段
FROM (SELECT DISTINCT ES_Eval_Result
FROM (SELECT ES_Eval_Result, COUNT(ES_ID) AS num, ES_Stage
FROM ES_EvaluateStandard AS ES_EvaluateStandard_1
WHERE (VP_ID = 28)
GROUP BY ES_Stage, ES_Eval_Result) AS es1_1) AS es2
当列“概念策划阶段”为null时转化为0

Answer 1

不知道你什么数据库。

如果是 Oracle
那么
NVL( (你那个子查询) , 0 ) AS 概念策划阶段

如果是 SQL Server
那么
ISNULL( (你那个子查询) , 0 ) AS 概念策划阶段

Answer 2

sqlserver 用 isnull (a,0) 的函数

oracle 用 nvl( a, 0) 的函数

通用的是
case when a is null then 0 else a end
的写法

Answer 3

直接用函数 NVL( (子查询) , 0 ) AS 概念策划

意思是如果 子查询为空则赋值为0如果不为空则赋值本身