What is the use of IFNULL and ISNULL in SQL?
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Answers ( 6 )
The IfNULL() and ISNULL() function lets you return an alternative value if the expression is NULL
Example:
select empname, IFNULL(salary,0) from employees.
Here, if the value of salary is NULL it will return 0 while querying the table.
IFNULL() is used in MySql
ISNULL() is used in SQL Server
IFNULL() and ISNULL() are two functions in sql to check the existence of null values in a particular column and replace with a value depending on the type of DB used.
ISNULL() in Sql server:- Checks for the null values and if it’s present it returns with an alternate value.
ISNULL(column_name, value_to_be_replaced)
ISNULL() in MYSQL :- Checks the column value if it is null or not null. It returns a boolean result.
IFNULL in MYSQL :- Checks for the null values and if it’s present it returns with an alternate value.
IFNULL(column_name, value_to_be_replaced)
IFNULL() is used in MySql
ISNULL() is used in SQL server
Both these functions when encounters a null value in a particular column returns a specified value as mentioned by the user
ISNULL()- Is used in both mysql and SQL server
SQL server — ISNULL(arugument1,argument2) -Returns argument2 if the argument 1 is NULL else will return Argument1
MYSQL – If the expression is null this will return 1 if the expression is not null this will return 0.It returns a boolean result
IFNULL() – Used in Mysql
It takes 2 conditions and returns the first condition if it is not null and returns the second condition
IFNULL( Condition1, condition2)
Both are used to identify null values for a specified column.
Major difference is IS NULL is used in SQL server database and IF NULL is used in MySQL database.
IFNULL is used to replace the null with a specified value, in a column. It returns a non-null value (if there is no null), else returns the replacement value.
for example – select ifnull(col_name,value)
ISNULL checks for the presence of null in a column.
for example – select * from table where col_name is null