Can I put an if statement in a WHERE clause SQL?

IF… ELSE clause is very handy and whenever you need to perform any conditional operation, you can achieve your results using it. But there are some limitations in IF… ELSE, and one of the limitations is that you cannot use it in WHERE clause.

Can functions be used in WHERE clause?

When functions are used in the SELECT clause to return uppercase output, a substring or whatever, it doesn’t affect performance that much, but when functions are used improperly in the WHERE clause these functions can cause major performance issues.

How do you write an if statement in SQL SELECT query?

You can have two choices for this to actually implement:

1. Using IIF, which got introduced from SQL Server 2012: SELECT IIF ( (Obsolete = ‘N’ OR InStock = ‘Y’), 1, 0) AS Saleable, * FROM Product.
2. Using Select Case : SELECT CASE WHEN Obsolete = ‘N’ or InStock = ‘Y’ THEN 1 ELSE 0 END as Saleable, * FROM Product.

Can we use extract function in WHERE clause in SQL?

With the help of following MySQL query, we can apply EXTRACT() function with WHERE clause on the dates stored in a table.

Does WHERE clause improve performance?

A where clause will generally increase the performance of the database. Generally, it is more expensive to return data and filter in the application. The database can optimize the query, using indexes and partitions. The database may be running in parallel, executing the query in parallel.

How can I retrieve data from SQL database?

The SQL SELECT Statement

1. SELECT column1, column2, FROM table_name;
2. SELECT * FROM table_name;
3. Example. SELECT CustomerName, City FROM Customers;
4. Example. SELECT * FROM Customers;

Does WHERE clause speed up query?

What is conditional logic SQL?

Conditional statements are used to define what logic is to be executed based on the status of some condition being satisfied. There are two types of conditional statements supported in SQL procedures: CASE.

What is the purpose of the where clause in SQL?

CONSTRAINT clause. A CONSTRAINT clause is an optional part of a CREATE TABLE statement or an ALTER TABLE statement.

EXTERNAL NAME clause.

FOR UPDATE clause.

FROM clause.

GROUP BY clause.

HAVING clause.

WINDOW clause.

ORDER BY clause.

Does SQL have if statements?

SQL Server provides the capability to execute real-time programming logic using SQL IF Statement. In the following SQL IF Statement, it evaluates the expression, and if the condition is true, then it executes the statement mentioned in IF block otherwise statements within ELSE clause is executed.

How do the where and having clauses differ in SQL?

– First, for each order line item, SQL calculates the total amount using the SUM function. (The Total column alias is used for formatting the output). – Second, the GROUP BY clause groups the selected rows by OrderID. – Third, the HAVING clause gets groups that have Total greater than 12000.

Can we use if else in where clause?

The IF-ELSE clause in SQL Server is quite useful, and we can use it to obtain the desired results whenever we need to execute any conditional operation. However, IF-ELSE has some limitations, one of which is that it cannot be used in the WHERE clause. Let’s understand this with the help of an example.