This functionality can be brought simply by specifying REVERSE after a counter variable is declared in for statement. Reverse Order Looping: In this, we will see where our counter will decrement in value whenever it iterates in the for loop instead of incrementing. The for loop iterates 10 times to print any table. Hence for printing the table of 5, the 5 number is multiplied by 1,2 and so on till 10, and a notice is displayed to print the table on the console. Now, to print the table, we will have to call the function displayTable() in the following way: select displayTable(5) So, after copying and pasting the above function in your psql command prompt, a function named displayTable will be created if CREATE FUNCTION is displayed at the end. Let us begin to be creating our function.Ĭode: CREATE OR REPLACE FUNCTION displayTable(int) RETURNS void AS $$

Let us first consider a simple example of printing the table of a particular integer that we pass to our function. Examples to Implement in PostgreSQL For Loopīelow are some examples of PostgreSQL For Loop: Example #1 Doing so will result in a wastage of CPU memory and execution and sometimes may crash the system.

It is necessary to define the range such that the looping should come to a halt and not iterate infinitely. The for loop can be placed inside a certain function’s body, and this function can be called whenever we have to execute the for loop defined by us. You include the statements that you want to execute on a repetitive basis in the section, and the END LOOP marks the end of the for loop’s operation.REVERSE is the optional parameter in which, when specified, the counting variable will be decremented while iterating instead of incrementing each time the iteration is done. And the LOOP keyword marks the beginning of the for loop’s body that will be executed each time the loop is iterated. The step value is the stepping amount that specifies how much value is to be skipped from the start value till the end value while iterating. This counting variable has a START VALUE and an END VALUE as its range for which it will iterate. You can declare it in the for loop statement itself. įor loop contains a counting variable that is unnecessary to declare outside the loop. Other than this, you should be aware of the arrays in PostgreSQL. To understand the examples, you need to have basic knowledge of PostgreSQL functions and CRUD operation statements like SELECT, UPDATE, INSERT and DELETE. Another type of looping statement is the loop, and the last one is the while loop. We can stop looping with a plain loop with the EXIT WHEN statement. In PostgreSQL, we have various types of looping facilities. You can use a loop to execute statements for a specific number of times or until your requirement is fulfilled.

Whenever we want to perform a certain task repetitively, we can loop through those statements that we want to perform repetitively. In programming, looping through statements is a common technique in the technical world. We often face a situation where we have to perform a specific activity multiple times in a repetitive fashion.

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Postgresql for loop insert