#Postgresql for loop code
The execution block contains all the code that needs to be executed, including the EXIT condition. PostgreSQL provides the for loop statements to iterate over a range of integers or over a result set or over the result set of a dynamic query. The LOOP keyword declares the beginning of the loop, and END LOOP declares the end of the loop. SELECT last_name, job_id, salary,ĮLSE salary END "REVISED_SALARY" FROM employees For all other job roles, there is no increase in salary. We can use CASE to evaluate multiple conditions for a single variable, “job_id.” If “job_id” is “ACCOUNT,” the salary increase is 10% if “job_id” is “IT_PROG,” the salary increase is 15% if “job_id” is “SALES,” the salary increase is 20%. Its also very complicated to implement autonomous txs in PostgreSQL for a variety of internal reasons related to its session and process model. To properly support them it really needs stored procedures, not just the user-defined functions it currently supports. It facilitates conditional inquiries by doing the work of an IF-THEN-ELSE statement and applying it to many possible conditions. PostgreSQL does not support autonomous transactions at this time (9.4). The different uses of the for loop in PostgreSQL are described below: 1. However, when you use the reverse option, the for loop subtracts the step from loopcounter. PostgreSQL provides the for loop statements to iterate over a range of integers or over a result set or over the result set of a dynamic query. By default, the for loop adds the step to the loopcounter after each iteration. The CASE statement uses IF-THEN-ELSE logic within a single statement. First, the for loop creates an integer variable loopcounter which is accessible inside the loop only. Next, there is one condition: when x is greater than y it raises notice that “x is greater than y.” When that condition is not met, it raises the notice “x is not greater than y.” In this case, the condition is not met, so the ELSE clause is executed and the output for the ELSE part is printed. If the condition is false then it goes to the next statement after END IF.Īs in the first example, here 2 variables are declared at the start: x=10 and y=20. While you can use a function, if you have PostgreSQL 9.3 or later, you can use a LATERAL subquery to perform subqueries for each row. In general, with SQL, you almost never need a FOR loop. loop deprecation warning) : name: - nginx - postgresql - postgresql-server. Im not sure if the proof of concept example does what you want. The IF condition runs when a condition is evaluated as true. Were updating the Ansible community mission statement. It is allowed to use a constant (or a variable, in plpgsql or in prepared statements) where an expression is needed: insert into foo (a,b,c) select 42, y, z from bar Note: in your code oldseasonnum is not even defined. There are three main types of control structures available with PostgreSQL to use with stored procedures: IF, CASE, and LOOP. Stored procedures in PostgreSQL are ones that define a function for creating triggers or custom functions. SUMMARY: This article reviews control structures that can be used in PostgreSQL stored procedures, with syntax and examples provided for each.
0 kommentar(er)
