l 传入课程编号,返回一个表中该课程的总分 l Create function fun_sumScore l { l @parClassNo as varchar(10) } l Returns real l Begin l Declare @sumScore real l Select @sumScore = sum(score) l From t_score l Where classNo=@parClassNo l Return @sumScore l End l 使用自定义函数: s...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL.We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return ...
MySQLNULLIF()Function ❮Previous❮ MySQL FunctionsNext❯ ExampleGet your own SQL Server Compare two expressions: SELECTNULLIF(25,25); Try it Yourself » Definition and Usage The NULLIF() function compares two expressions and returns NULL if they are equal. Otherwise, the first expression is...
You might wonder how you can use this function in your queries. The answer is: it helps youavoid division by zero. Take a look at this theoretical example: Let's say we have10000 USDand we want to give equal portions of this amount to some people. We know that the number of these ...
MySQL offers two methods for determining a NULL value and replacing it with another. In SQL Server the function IFNULL is available and in Oracle NVL. However, standard standard SQL shows us that the COALESCE function is standard ANSI SQL and would standardize your SQL code. ...
SQL SERVERNULLIF ## SQL SERVERNULLIF在SQL Server中,我们经常需要处理包含NULL值的数据。在处理这些数据时,经常会遇到一些问题,例如在计算或比较数据时,NULL值可能会导致错误或不正确的结果。为了解决这些问题,SQL Server提供了一个非常有用的函数`NULLIF`。 `NULLIF`函数用于比较两个表达式,并在它们相等时返回NULL...
Per trovare la media solo dei reparti che ricevono un budget e includere inoltre il valore del budget dell'anno precedente (utilizzare il valore previous_year se current_yearè NULL), vengono combinate le funzioni NULLIF e COALESCE.SQL Copia CREATE TABLE dbo.budgets ( dept TINYINT IDENTITY,...
Remarks NULLIF is equivalent to a searched CASE function in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluted twice and to ...