Oracle中模拟SQL中的isnull函数 程序从MS SQL移植到ORACLE,面临大面积的SQL语句修改,其中用的最多的莫非isnull,虽然oracle中有nvl ,nullif, is null等函数,但却没有isnull。自己写一个吧,但是因为类似ISNULL(),NVL()的函数入参和返回值的数据类型都并不确定,要如何定义类型?姑且用varchar2吧:请看下面测试代码...
It checks for the empty values inside the database and replaces them with an alternate value as specified in the NVL() function.The difference is that the isnull() function has been replaced with the NVL() function, an Oracle function in the SQL server....
SQL Server / MS Access,代码如下: SELECTProductName,UnitPrice*(UnitsInStock+ISNULL(UnitsOnOrder,0)) FROMProducts Oracle Oracle does not have an ISNULL() function. However, we can use the NVL() function to achieve the same result,代码如下: SELECTProductName,UnitPrice*(UnitsInStock+NVL(Units...
The Oracle NVL function can use string, date, and number values, for both the check_value and replace_value. However, they both need to be the same type. If a string is used for the check_value, a string also needs to be used for the replace_value. SQL ISNULL Function Syntax and ...
The MS AccessIsNull()function returns TRUE (-1) if the expression is a null value, otherwise FALSE (0): SELECTProductName, UnitPrice * (UnitsInStock + IIF(IsNull(UnitsOnOrder),0, UnitsOnOrder)) FROMProducts; Oracle The OracleNVL()function achieves the same result: ...
ISNULL()函数的分类: ISNULL()函数属于数据库查询语言中的函数,常见的数据库查询语言有SQL、MySQL、Oracle等。 ISNULL()函数的优势: ISNULL()函数的优势在于可以方便地处理数据库查询结果中的空值情况。通过使用ISNULL()函数,可以避免在程序中对空值进行额外的判断和处理,提高代码的简洁性和可读性。
SQL函数 ISNULL 测试NULL并返回相应表达式的函数。...请注意,ISNULL函数与NVL函数相同,后者是为了与Oracle兼容而提供的。日期和时间显示转换某些检查表达式数据类型需要从逻辑模式转换为ODBC模式或显示模式。例如日期和时间数据类型。...比较的NULL处理函数下表显示了
Example Oracle Function Syntax In Oracle we have two functions that do the same job: COALESCE() and NVL(), the latter being an old proprietary function of PL/SQL that behaves like ISNULL() in SQL Server. Oracle COALESCE Function Let's try the same examples. ...
Re: ISNULL function 16674 Steve Brinton March 30, 2009 06:05AM Sorry, you can't reply to this topic. It has been closed. Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the op...
$err_mess = (CTicket::err_mess())."Function: GetSupportTeamMailListLine: ";global$DB; $strSql =" SELECT U.ID as ID, U.LOGIN as LOGIN, ". $DB->Concat(CTicket::isnull("U.LAST_NAME","''"), CTicket::isnull("U.NAME","''"),'U.LOGIN')." as NAME, U.EMAIL as...