如果为null则返回零

Question

我有一个选择陈述

  select 
  name
  ,age
  from table_employees
  where id=@impId;

我想检查年龄是否为零而不是返回零。我试过跟随，但它不起作用

     select 
     name
     ,age isnull(age,0.00)
     from table_employees
     where id=@impId;

请让我知道如何解决这个问题。 谢谢

Answer 1

建议经常被忽视的COALESCE：

select 
   name, 
   coalesce(age, 0.00) as age_not_null 
from table_employees 
where id = @impId;

Answer 2

在SQL Server 2005或更高版本中，您可以使用COALESCE函数：

SELECT
    name
,   COALESCE(age, 0) as age
FROM table_employees
WHERE id=@impId

该函数逐个计算其参数，并返回第一个非NULL值。

Answer 3

试试这种方式

select 
name,age=isnull(age,0.00)
from table_employees
where id=@impId;

或

select 
name,
isnull(age,0.00) as age 
from table_employees
where id=@impId;

Answer 4

你可以试试这个： -

select 
    name
,   COALESCE(age,0) as age
from table_employees
where id=@impId;

Answer 5

请尝试以下：

 select 
 name
 ,isnull(age,0.00)
 from table_employees
 where id=@impId;

Answer 6

尝试：

 SELECT name,isnull(age,0) 
 FROM table_employees
 WHERE id=@impId;

Answer 7

ISNULL是SQL Server的语句。你不能把列名放在它之前。

所以，试试这个：

SELECT name, ISNULL(age,0.00) AS age
FROM table_employees
WHERE id=@impId;