How can use while loop in select statement in SQL Server?
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.
Can we use loop in select statement?
The following example declares an explicit cursor and uses it in the cursor FOR LOOP statement. In this example, the SELECT statement of the cursor retrieves data from the products table. The FOR LOOP statement opened, fetched each row in the result set, displayed the product information, and closed the cursor.
Can we use loop in SQL query?
SQL WHILE loop provides us with the advantage to execute the SQL statement(s) repeatedly until the specified condition result turn out to be false. If the result of the condition is true, the SQL statement will be executed. … Otherwise, the code flow will exit the loop.
How do you apply a loop in SQL query?
I am detailing answer on ways to achieve different types of loops in SQL server.
- FOR Loop. DECLARE @cnt INT = 0; WHILE @cnt < 10 BEGIN PRINT ‘Inside FOR LOOP’; SET @cnt = @cnt + 1; END; PRINT ‘Done FOR LOOP’;
- DO.. WHILE Loop. …
- REPEAT..UNTIL Loop.
How do you loop a select statement?
Select loops perform an implicit next operation each time the loop is executed. In addition, an explicit next statement within the body of the loop causes the next row of the data to be selected. Statement execution continues with the statement immediately following next. The loop terminates at the end of the data set.
How do you write a case statement in SQL query?
SQL CASE Statement
- CASE. WHEN condition1 THEN result1. WHEN condition2 THEN result2. WHEN conditionN THEN resultN. ELSE result. …
- Example. SELECT OrderID, Quantity, CASE. WHEN Quantity > 30 THEN ‘The quantity is greater than 30’ …
- Example. SELECT CustomerName, City, Country. FROM Customers. ORDER BY.
What is difference between simple loop while loop & FOR loop?
for loop: for loop provides a concise way of writing the loop structure. Unlike a while loop, a for statement consumes the initialization, condition and increment/decrement in one line thereby providing a shorter, easy to debug structure of looping.
What can a cursor FOR loop use?
The cursor FOR LOOP statement implicitly declares its loop index as a record variable of the row type that a specified cursor returns, and then opens a cursor. With each iteration, the cursor FOR LOOP statement fetches a row from the result set into the record.
How can I use cursor in SQL Server?
Cursor in SQL Server
- DECLARE statements – Declare variables used in the code block.
- SETSELECT statements – Initialize the variables to a specific value.
- DECLARE CURSOR statement – Populate the cursor with values that will be evaluated. …
- OPEN statement – Open the cursor to begin data processing.
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 create an array in SQL query?
Define arrays as SQL variables. Use the ARRAY_AGG built-in function in a cursor declaration, to assign the rows of a single-column result table to elements of an array. Use the cursor to retrieve the array into an SQL out parameter. Use an array constructor to initialize an array.
How do I do an if statement in SQL?
The IF statement is logically equivalent to a CASE statements with a searched-case-statement-when clause. The IF statement supports the use of optional ELSE IF clauses and a default ELSE clause. An END IF clause is required to indicate the end of the statement.