Mysql if result is empty

This MySQL tutorial explains how to use the MySQL IS NULL condition with syntax and examples.

Description

The MySQL IS NULL Condition is used to test for a NULL value in a SELECT, INSERT, UPDATE, or DELETE statement.

Syntax

The syntax for the IS NULL Condition in MySQL is:

expression IS NULL

Parameters or Arguments

Note

• If expression is a NULL value, the condition evaluates to TRUE.
• If expression is not a NULL value, the condition evaluates to FALSE.

Example - With SELECT Statement

Let's look at an example of how to use MySQL IS NULL in a SELECT statement:

SELECT *
FROM contacts
WHERE last_name IS NULL;

This MySQL IS NULL example will return all records from the contacts table where the last_name contains a NULL value.

Example - With INSERT Statement

Next, let's look at an example of how to use MySQL IS NULL in an INSERT statement:

INSERT INTO contacts
(contact_id, contact_name)
SELECT account_no, supplier_name
FROM suppliers
WHERE category IS NULL;

This MySQL IS NULL example will insert records into the contacts table where the category contains a NULL value.

Example - With UPDATE Statement

Next, let's look at an example of how to use MySQL IS NULL in an UPDATE statement:

UPDATE contacts
SET last_name = 'TBD'
WHERE last_name IS NULL;

This MySQL IS NULL example will update records in the contacts table where the last_name contains a NULL value.

Example - With DELETE Statement

Next, let's look at an example of how to use MySQL IS NULL in a DELETE statement:

DELETE FROM contacts
WHERE last_name IS NULL;

This MySQL IS NULL example will delete all records from the contacts table where the last_name contains a NULL value.

Mysql Select If Empty Result With Code Examples

In this session, we are going to try to solve the Mysql Select If Empty Result puzzle by using the computer language. The code that follows serves as an illustration of this point.

SELECT IFNULL( (SELECT field1 FROM table WHERE id = 123 LIMIT 1) ,'not found');

As we have seen, a large number of examples were utilised in order to solve the Mysql Select If Empty Result problem that was present.

How do I check if a field is empty in MySQL?

SELECT * FROM yourTableName WHERE yourSpecificColumnName IS NULL OR yourSpecificColumnName = ' '; The IS NULL constraint can be used whenever the column is empty and the symbol ( ' ') is used when there is empty value.24-Jun-2020

What does select return if not found MySQL?

It returns either field1 if the row exists, otherwise 0.16-Sept-2012

How do I assign a default value if no rows returned from the select query MySQL?

SELECT *, IFNULL( ( SELECT col1 FROM table1 WHERE col1 IN ('012311','0123631','091233','092111') ), 'some_value' ) AS my_col1 FROM table1; Not neccessarily copy+paste, you will have to adjust for your specific case.

Can SQL query return null?

The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

Is NULL in SELECT MySQL?

Description. The MySQL IS NOT NULL condition is used to test for a NOT NULL value in a SELECT, INSERT, UPDATE, or DELETE statement.

How do you check if a column is empty or not?

Re: Determine if column is empty The formula =COUNTA(A1:A100) will return the number of non-blank cells in the range A1:A100.27-Sept-2021

How do I SELECT all NULL values in SQL?

How to Test for NULL Values?

• SELECT column_names. FROM table_name. WHERE column_name IS NULL;
• SELECT column_names. FROM table_name. WHERE column_name IS NOT NULL;
• Example. SELECT CustomerName, ContactName, Address. FROM Customers. WHERE Address IS NULL;
• Example. SELECT CustomerName, ContactName, Address. FROM Customers.

Is NULL and is not null in MySQL?

“IS NULL” is the keyword that performs the Boolean comparison. It returns true if the supplied value is NULL and false if the supplied value is not NULL. “NOT NULL” is the keyword that performs the Boolean comparison. It returns true if the supplied value is not NULL and false if the supplied value is null.26-Jul-2022

IS NOT NULL condition in SQL?

The IS NOT NULL condition is used in SQL to test for a non-NULL value. It returns TRUE if a non-NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

How do you set a default row for a query that returns no rows?

Linked

• SQL – Return 0 When results are empty.
• Set default value in select statement(not use UNION statement)
• Display data in SSRS.
• sql select a default row if the result is not found.
• Adding dummy data to a column in SQL Server.

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