The following illustrates the general form of the CASE statement: CASEĮND Code language: SQL (Structured Query Language) ( sql ) The CASE expression has two forms: general and simple form. Since CASE is an expression, you can use it in any places where an expression can be used e.g., SELECT, WHERE, GROUP BY, and HAVING clause. It allows you to add if-else logic to the query to form a powerful query. The PostgreSQL CASE expression is the same as IF/ELSE statement in other programming languages. Additionally, you learned about the three forms of Postgresql If Else.Summary: in this tutorial, you will learn how to use the PostgreSQL CASE conditional expression to form conditional queries. In this PostgreSQL tutorial, you have covered how to implement Postgresql If Else Statement to handle multiple conditions and execute the query or command accordingly. ![]() So using PostgreSQL If else with ELSIF, you can use multiple conditions by specifying ELSIF to perform the different operations on the database accordingly or execute the query according to the condition to get the desired result. So the employee with a salary greater than $50000 in the sales department gets an increment of $500 by executing the code within the ELSEIF block. In the above code, first the condition (If exists (SELECT FROM employees WHERE department=’Sales’ and salary 50000)) within ELSEIF is checked and it evaluates to true. RAISE NOTICE 'No employee in sales and marketing with salry less than 5000 respectively' Then uses the IF statement to compare the values ( if value_1 50000) THEN The two variables value_1 and value_2 are initialized with values 20 and 50 respectively in the declare section of the above code. Raise notice'The value_1 is smaller than value_2' Use the below command to find the smaller value between two values. Consider you have two variables containing an integer value and you want to find which value is smaller, for that, you can use the IF statement to compare the value and get the output to know which one is smaller. In this section, I will show you the PostgreSQL if else example using only the IF statement. Postgresql If Else Statement using only IF Statement So the condition within IF (If exists (SELECT FROM employees WHERE department=’Sales’ and salary > 70000)) is evaluated as false and the code within ELSE (UPDATE employees SET salary=salary + 5000 WHERE department=’Sales’) gets executed. From the first example, you know that there wasn’t any employee with a salary greater than or equal to $70000 in the sales department. ![]() Let’s take some examples and for the example, you will use the table ’employees’ which is shown below.Īgain look at the above code, the salary of employees Tims and Tonny incremented by $5000 because this time the code within the ELSE block gets executed. This is used where you know there can be multiple situations for the execution of different queries or commands. This is the nested variant of the IF ELSE statement, it gives you more control over the flow of the program compared to the second variant of IF. Third variant: IF contion_or_expression THEN If the query or command doesn’t execute due to a false condition of the IF statement, then the query within ELSE gets executed. This variant of IF ELSE provides you more control over the flow of the program compared to only the first variant of IF. Second variant: IF contion_or_expression THEN This variant of IF is used where you need to execute the command and query for the specific condition only, if the condition is not met then the execution of the query should not have any effect. Write here the query or command that you want to execute There are three variants of the If statement:įirst variant: IF contion_or_expression THEN ![]() Here the condition is a boolean expression that is a true or false value, if the condition is true then the query for this condition is executed otherwise query within ELSE gets executed. It allows you to execute a specific query for a specific condition. The If controls the flow of the program in PostgreSQL like the If Else statement in other programming languages. PostgreSQL If statement gives you control to execute the command or query based on the given condition. Introduction to Postgresql If Else Statement Postgresql If Else Statement using only IF Statement.Introduction to Postgresql If Else Statement.
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