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How do you write a while loop in PL SQL?

How do you write a while loop in PL SQL?

Example of PL/SQL While Loop

  2. i INTEGER := 1;
  3. BEGIN.
  4. WHILE i <= 10 LOOP.
  6. i := i+1;
  7. END LOOP;
  8. END;

What is Do While loop syntax in Oracle?

The WHILE loop syntax PL/SQL evaluates the condition in the WHILE clause before each loop iteration. If the condition is TRUE , then the loop body executes. In case it is FALSE or NULL , the loop terminates. If the condition is FALSE before entering the loop, the WHILE loop does not execute at all.

How do you do a while loop in SQL?

SQL While loop syntax The while loop in SQL begins with the WHILE keyword followed by the condition which returns a Boolean value i.e. True or False. The body of the while loop keeps executing unless the condition returns false. The body of a while loop in SQL starts with a BEGIN block and ends with an END block.

How does for loop work in PL SQL?

In this loop structure, sequence of statements is enclosed between the LOOP and the END LOOP statements. At each iteration, the sequence of statements is executed and then control resumes at the top of the loop. Repeats a statement or group of statements while a given condition is true.

How many types of loop are there in PL SQL?

4 types

Why do we use loops in PL SQL?

PL/SQL for loop is used when when you want to execute a set of statements for a predetermined number of times. The loop is iterated between the start and end integer values. The counter is always incremented by 1 and once the counter reaches the value of end integer, the loop ends.

How do you stop an infinite loop in PL SQL?

With each iteration of the loop, the sequence of statements is executed, then control resumes at the top of the loop. You use an EXIT statement to stop looping and prevent an infinite loop. You can place one or more EXIT statements anywhere inside a loop, but not outside a loop.

How do you loop through a string in PL SQL?

v_length Loop v_out := substr(IN_string,i,1) ; DBMS_OUTPUT. PUT_LINE(v_out); End loop; DBMS_OUTPUT. PUT_LINE(‘Text printed: ‘ || IN_string); End; — Procedure created. BEGIN print_string(‘Hello’); END; — Output: H e l l o Text printed: Hello Statement processed.

Can we loop in SQL?

In programming, a loop allows you to write a set of code that will run repeatedly within the same program. Many programming languages have several different types of loop to choose from, but in SQL Server there is only one: the WHILE loop.

What are 3 types of loops in SQL?

Explain Different Types of Loops in PL/SQL

  • The simple or infinite loop.
  • The FOR loop.
  • The WHILE loop.

How do you loop through a column in SQL?


  2. GO.
  4. — Declare your array table variable.
  5. DECLARE @MYARRAY table (TEMPCOL nvarchar(50), ARRAYINDEX int identity(1,1) )

How do you run a loop in SQL query?

PL/SQL – FOR LOOP Statement

  1. The initial step is executed first, and only once. This step allows you to declare and initialize any loop control variables.
  2. Next, the condition, i.e., initial_value ..
  3. After the body of the for loop executes, the value of the counter variable is increased or decreased.
  4. The condition is now evaluated again.

What is the function of while loop?

The while loop is used to repeat a section of code an unknown number of times until a specific condition is met. For example, say we want to know how many times a given number can be divided by 2 before it is less than or equal to 1.

Which of the following is used to end for loop in PL SQL?

EXIT statement

How do you query a for loop?

SOQL for loops iterate over all of the sObject records returned by a SOQL query. The syntax of a SOQL for loop is either: for (variable : [soql_query]) { code_block….For example:

  1. String s = ‘Acme’;
  2. for (Account a : [SELECT Id, Name from Account.
  3. where Name LIKE :(s+’%’)]) {
  4. // Your code.
  5. }

Can we write SOQL query in for loop?

Avoid SOQL Queries or DML Statements inside ‘FOR Loops’ : When SOQL queries and DML statements are placed inside a ‘for loop’, these are invoked for every iteration of the loop. Because of this, governor limits will be reached, so it would be best to avoid these scenarios whenever possible.

How do I write SOQL outside for loop?

list listOpportunity = [select id From opportunity Where id IN : *Trigger. oldmap. keyset()];* for(Opportunity opportunity : listOpportunity) { //Do Code here. }

How do you write a for loop in MySQL?

The MySQL LOOP statement could be used to run a block of code or set of statements, again and again, depends on the condition.

  1. Syntax : [labelname:] LOOP statements END LOOP [labelname]
  2. Parameters –
  3. Example-1 :
  4. Output – 0, 1, 2, 3, 4, 5.

Can we use while loop in MySQL?

MySQL WHILE loop statement is used to execute one or more statements again and again, as long as a condition is true. We can use the loop when we need to execute the task with repetition while condition is true.

Can we use for loop in MySQL?

MySQL LOOP statement example In this example: The stored procedure constructs a string from the even numbers e.g., 2, 4, and 6. The loop_label before the LOOP statement for using with the ITERATE and LEAVE statements. If the value of x is greater than 10 , the loop is terminated because of the LEAVE statement.

What is MySQL delimiter?

A MySQL client program such as MySQL Workbench or mysql program uses the delimiter ( ; ) to separate statements and executes each statement separately. However, a stored procedure consists of multiple statements separated by a semicolon (;).

Why is delimiter used in MySQL?

You define a DELIMITER to tell the mysql client to treat the statements, functions, stored procedures or triggers as an entire statement. Normally in a . sql file you set a different DELIMITER like $$. The DELIMITER command is used to change the standard delimiter of MySQL commands (i.e. ;).

What is delimiter in PL SQL?

A delimiter is a simple or compound symbol that has a special meaning to PL/SQL. For example, you use delimiters to represent arithmetic operations such as addition and subtraction.

What is MySQL procedure?

A procedure is a subroutine (like a subprogram) in a regular scripting language, stored in a database. In the case of MySQL, procedures are written in MySQL and stored in the MySQL database/server. A MySQL procedure has a name, a parameter list, and SQL statement(s).

Does MySQL have stored procedures?

MySQL supports stored routines (procedures and functions). A stored routine is a set of SQL statements that can be stored in the server. Banks, for example, use stored procedures and functions for all common operations.

How do hackers use SQL injection?

Using SQL injection, a hacker will try to enter a specifically crafted SQL commands into a form field instead of the expected information. The intent is to secure a response from the database that will help the hacker understand the database construction, such as table names.