SQLite NullIf() Function

Here we will learn NullIf() function in SQLite and how to use SQLite NullIf() function to return a NULL value if defined parameters are equal.

SQLite NULLIF() Function

Generally in SQLite NULLIF() function will accept two parameters and it returns a NULL value in case if both the parameters are equal otherwise it will return first parameter.

 

The NULLIF() function will return NULL value in case if both the parameters are equal to NULL.

 

The SQLite NULLIF() function will perform a case-sensitive comparison while comparing two parameters.

Syntax of SQLite Nullif() Function

Following is the syntax of Nullif() function to return NULL or First parameter value based on the defined parameter values.

 

nullif( param1, param2 )

The above SQLite nullif() syntax contains few properties those are

 

param1, param2 – Two parameters to check if param1 = param2 or not to return NULL or first expression value.

 

Now we will see how to use SQLite Nullif() function to return NULL or first expression based on the defined parameter values with examples.

SQLite Nullif() Function with Examples

The following are the simple examples of using SQLite Nullif() Function to return NULL or first expression based on the defined expression values.

 

sqliteSELECT  nullif('tutlane','tutlane');

 

nullif("tutlane","tutlane")

---------------------------

NULL

 

sqliteSELECT  nullif('Tutlane','tutlane');

 

nullif("Tutlane","tutlane")

---------------------------

Tutlane

 

sqliteSELECT  nullif('Welcome','Tutlane');

 

nullif("Welcome","Tutlane")

------------------------

Welcome

 

sqliteSELECT nullif(NULL,NULL);

 

nullif(NULL, NULL)

--------------------------

NULL

SQLite Nullif() Function with Tables

Now we will see how to use Nullif() function with table columns for that create tables called emp_master, dept_master and insert some records like as shown following

 

sqliteselect from dept_master;

 

dept_id     dept_name

----------  ----------

1           Admin

2           Sales

3           Quality Co

4           Marketing

 

sqliteselect from emp_master;

 

emp_id      first_name  last_name   salary      dept_id

----------  ----------  ----------  ----------  ----------

2           Shweta      Jariwala    19300       2

3           Vinay       Jariwala    35100       3

4           Jagruti     Viras       9500        2

5           Shweta      Rana        12000       3

6           Sonal       Menpara     13000       1

7           Yamini      Patel       10000       2

8           Khyati      Shah        50000       3

9           Shwets      Jariwala    19400       2

Now write the query like as shown following to compare department id of both emp_master and dept_master using NULLIF() function.

 

sqliteSELECT nullif((SELECT dept_id FROM dept_master),(SELECT dept_id FROM emp_master));

 

nullif(dept_master, emp_master)

-------------------------------

4

This is how we can use SQLite Nullif() function to compare two parameter values and get result based on our requirements.