Null and Not Null Condition in SQL In the same way that every other programming language has a conditional operator that returns True or False, there is a conditionals operator in SQL that returns Null or Not Null.
In SQL, the IS NOT NULL condition is used to check for non-NULL values. If a non-NULL value is detected, it returns TRUE; otherwise, it returns FALSE. In a SELECT, INSERT, UPDATE, or DELETE statement, it can be utilised.
The is null() method is used to determine whether a variable is null or not. If a variable has no value stored in it, it is deemed NULL. If the value of variable $var is NULL, it returns TRUE; otherwise, it returns FALSE.
The isset() function determines whether a variable is set, that is, whether it has been declared and is not NULL. If the variable exists and is not NULL, this method returns true; otherwise, it returns false.
In a SELECT statement, here's an example of how to use the MySQL IS NOT NULL condition: SELECT * FROM contacts WHERE last name IS NOT NULL; This MySQL IS NOT NULL example returns all records from the contacts table that do not have a null value for last name.
The is null() method determines whether or not a variable is NULL. If the variable is NULL, this method returns true (1); otherwise, it returns false/nothing.
Rajiv Kumar Singh
It would have been better if you could have provided the resource/source_code files of the CRUD operations so that we could have cross verified our code with yours.
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Muhammad Arif jamal
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I'm getting a fatal error insted of warning and also it's not showing the if condition statement.