ここで示す case 式 の構文は、ストアドプログラム内部で使用するために、セクション13.6.5.1「case 構文」で説明した sql case ステートメント の構文とはわずかに異なります。 case ステートメントは else null 句を持つことができず、end でなく、end case で終了します。

This MySQL tutorial explains how to use the IF-THEN-ELSE statement in MySQL with syntax and examples. Definition and Usage. mysql 5.7, mysql 5.6, mysql 5.5, mysql 5.1, mysql 5.0, mysql 4.1, mysql 4.0, mysql 3.23 Example Let's look at some MySQL IFNULL function examples and explore how to use the IFNULL function in MySQL. The syntax of the CASE expr described here differs slightly from that of the SQL CASE statement described in Section 13.6.5.1, “CASE Statement”, for use inside stored programs.The CASE statement cannot have an ELSE NULL clause, and it is terminated with END CASE instead of END.

The IFNULL() function returns a specified value if the expression is NULL. The MySQL IFNULL() function lets you return an alternative value if an expression is NULL: SELECT ProductName, UnitPrice * (UnitsInStock + IFNULL(UnitsOnOrder, 0)) FROM Products; or we can use the COALESCE() function, like this: In the event that the said is NULL, it returns TRUE, else FALSE.

In the event that the said is NULL, it returns TRUE, else FALSE. Example.
Syntax.

In MySQL, the IF-THEN-ELSE statement is used to execute code when a condition is TRUE, or execute different code if the condition evaluates to FALSE.

MySQL IFNULL function is one of the MySQL control flow functions that accepts two arguments and returns the first argument if it is not NULL.Otherwise, the IFNULL function returns the second argument. String Functions ... MySQL. Summary: in this tutorial, you will learn about the MySQL IFNULL function, which is a very handy control flow function to handle NULL values.. Introduction to MySQL IFNULL function. In MySQL ISNULL() work is used to test whether a said is NULL or not. MySQL IFNULL() Function MySQL Functions.

If the expression is NOT NULL, this function returns the expression. The syntax of MySQL ISNULL –

IFNULL(expression, alt_value) ... From MySQL 4.0: More Examples. MySQL Functions.