rec_count: is the number of rows to query from the film table.sort_type: 1 to sort the films by title, 2 to sort the films by release year.The following block shows how to use the for loop statement to loop through a dynamic query. The using clause is used to pass parameters to the query.The query_expression is an SQL statement.The following form of the for loop statement allows you to execute a dynamic query and iterate over its result set: įor row in execute query_expression ] NOTICE: Worst Banger(185 mins) Code language: Shell Session ( shell ) Using PL/pgSQL for loop to iterate over the result set of a dynamic query $$ Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) NOTICE: Chicago North(185 mins) Limit 10 loop raise notice '%(% mins)', f.title, f.length The following statement uses the for loop to display the titles of the top 10 longest films. The following statement shows how to use the for loop statement to iterate over a result set of a query: NOTICE: Counter 5 Code language: Shell Session ( shell ) Using PL/pgSQL for loop to iterate over a result set It adds 2 to the counter after each iteration: do $$ begin for counter in 1.6 by 2 loop raise notice 'counter: %', counter The following example uses the for loop statement to iterate over six numbers from 1 to 6. NOTICE: Counter: 1 Code language: Shell Session ( shell ) The following example iterates over 5 numbers from 5 to 1 and shows each number in each iteration: do $$ begin for counter in reverse 5.1 loop raise notice 'counter: %', counter NOTICE: Counter: 5 Code language: Shell Session ( shell ) The following example uses the for loop statement to iterate over five numbers from 1 to 5 and display each of them in each iteration: do $$ begin for counter in 1.5 loop raise notice 'counter: %', counter Įnd $$ Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) The following flowchart illustrates the for loop statement: The for loop evaluates this step expression once only. Third, the step that follows the by keyword specifies the iteration step.The for loop evaluates these expressions before entering the loop. Second, the from and to are expressions that specify the lower and upper bound of the range.However, when you use the reverse option, the for loop subtracts the step from loop_counter. By default, the for loop adds the step to the loop_counter after each iteration. First, the for loop creates an integer variable loop_counter which is accessible inside the loop only.to loopĮnd loop Code language: PostgreSQL SQL dialect and PL/pgSQL ( pgsql ) The following illustrates the syntax of the forloop statement that loops through a range of integers: įor loop_counter in from. Using PL/pgSQL for loop to iterate over a range of integers Summary: in this tutorial, you will learn about PL/pgSQL for loop statements to iterate over a range of integers or a result set of a query.
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