SQL IsNull Function

Interactive SQL

For Insert SQL For Update SQL For Select SQL For Delete SQL Learn Programmer
Level SQL

SQL Fundas

SQL Select SQL Insert SQL Update SQL Delete SQL Distinct SQL Where SQL And & Or SQL Order By SQL Data Types SQL Cross Join SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL Self Join SQL Union SQL Top SQL Like SQL Wildcards SQL In SQL Between SQL Alias SQL Select Into SQL Create Table SQL Drop SQL Alter SQL Constraints SQL Not Null SQL Unique SQL Primary Key SQL Foreign Key SQL Check SQL Default SQL Create Index SQL Identity SQL Views SQL Dates SQL Nulls SQL IsNull() SQL NullIf() SQL Create DB

SQL Functions

SQL Functions SQL Count() SQL Sum() SQL Min() SQL Max() SQL Len() SQL Round() SQL Upper() SQL Lower() SQL Avg() SQL Group By SQL Having SQL PatIndex() SQL Substring() SQL Sqrt() SQL Rand() SQL Concat()

« Previous Chapter

Next Chapter »

SQL Tutorial - IsNull Function

IsNull function is a SQL Server function. It replaces a null value with a predefined value found inside the function.

The Null Value

The 'IsNull" function consists of two parameters. If the first parameter evaluates to a NULL value then the second parameter's value defined in the function is returned else first parameter's value is returned.

IsNull Syntax

ISNULL (check_expression ,replacement_value)

As seen above if the check_expression returns a null value, then the null value will be replaced by the replacement value.

IsNull example

Select StudentID,StudentName, ISNULL(Height,165) As StudentHeight from Students

In the above example, we have a 'Students' table which takes in the 'Height' details of each student. Since it is an optional column ie. while entering a students record, this column can be omitted. So while taking the list height of all the students details, we are assumming that all null values of height be replaced by 165.

« Previous Chapter

Next Chapter »