Postgresql function multiple queries PostgreSQL functions can return values, just like any other SQL function. This variable will be used to store the rows coming from the query in the main body of the function. This not only simplifies your code but also makes it more efficient by reducing the number of queries that need to be executed. Here's an example of a PostgreSQL function that returns a string: Jul 1, 2016 · In terms of your actual query this syntax should work in PostgreSql, Oracle, and sql-server, well the later typically you will proceed WITH with a semicolon (;WTIH), but that is because typically sql-server folks (myself included) don't end previous statements which need to be ended prior to a CTE being defined The major difference: this function can return 0, 1 or many rows, while the first version always returns 1 row. Function Overloading: PostgreSQL supports function overloading, meaning we can create multiple functions with the same name but different parameter lists. A function has only one result set, regardless how many statements produce the output. You can use multiple instances in a single function to add more rows to the output. The function starts off by declaring a variable r to be of the rowtype holder. WITH cte AS (SELECT carto_id_key FROM table1 WHERE tag_id = 16) SELECT carto_id_key FROM cte UNION ALL SELECT t2. carto_id_key Oct 24, 2024 · Important Points About PostgreSQL CREATE FUNCTION Statement. Immutable functions always return the same Jan 29, 2019 · Yeah, I did that but unfortunately forgot to post it here, I'm editing it right now! As far as my understanding is concerned we can't run SQL statements between BEGIN and END clause in Postgres, but rather write all the SQL's by itself and select everything at one shot and run it accordingly. db<>fiddle here Feb 20, 2025 · The basic value of SELECT in WITH is to break down complicated queries into simpler parts. Oct 19, 2022 · Mark your function language sql, or; Add RETURN before SELECT to return the output of the query. First, you need to define a variable to hold the dynamic query string. Typical example: A table with a few rows is filled with many thousands of rows, but the next plan still thinks a sequential scan is fastest for the "small" table. Immutable, Stable, Volatile: Functions can be marked as IMMUTABLE, STABLE, or VOLATILE. Add LIMIT 1 like demonstrated to only allow 0 or 1 row. This is done by writing the base SQL command and adding an INTO clause. CREATE FUNCTION test() RETURNS SETOF RECORD AS $$ DECLARE rec record; BEGIN select 1,2 into rec; return next rec; select 3,4 into rec; return next rec; END $$ language plpgsql; Executing a Query with a Single-row Result" (emphasis mine): The result of a SQL command yielding a single row (possibly of multiple columns) can be assigned to a record variable, row-type variable, or list of scalar variables. carto_id_key = ctex. Sep 11, 2023 · I need to return two (or more) queries from a PostgreSQL-stored procedure. some_other_id_key FROM cte JOIN table2 t2 ON t2. . Feb 11, 2024 · For example, you can use multiple RETURN NEXT or RETURN QUERY statements in my_func() which returns SETOF RECORD type as shown below:. RETURN QUERY is simple way to return results from a query directly. * PostgreSQL Stored Procedures and Functions - Getting Started To return one or more result sets (cursors in terms of PostgreSQL), you have to use refcursor return type. In PL/pgSQL, the output of SELECT must go somewhere (usually a variable). You can specify the return type when you create the function, and then use the RETURN statement to return a value from the function. An example is: WITH regional_sales AS ( SELECT region, SUM(amount) AS total_sales FROM orders GROUP BY region ), top_regions AS ( SELECT region FROM regional_sales WHERE total_sales > (SELECT SUM(total_sales)/10 FROM regional_sales) ) SELECT region, product, SUM(quantity) AS product_units, SUM(amount) AS PostgreSQL functions are user-defined functions that allow you to encapsulate complex SQL queries into a single function. Jan 10, 2014 · Now im using 4 different connections witch fork to background and fires query with WHERE clause set to iterate over modulo of row id's to speed this up, ( WHERE id_field % 4 = ) and this works well and cuts down table populate to ~10 mins. Sep 19, 2017 · The function needs to return a SETOF RECORD instead of RECORD and have one RETURN NEXT per row instead of a single RETURN, as in:. In SQL, it’s implied the output is returned. The PL/pgSQL function is a little more complicated, but let's go through it. CREATE FUNCTION my_func() RETURNS SETOF RECORD AS $$ DECLARE row RECORD; BEGIN FOR row IN VALUES ('John','Smith'), ('David','Miller') LOOP RETURN NEXT row; -- Here END LOOP; FOR row IN VALUES ('Robert','Wilson'), ('Mark','Taylor') LOOP RETURN NEXT row; -- Here Apr 6, 2013 · Use a CTE to reuse the result from a subquery in more than one SELECT. So this should work: How to return values from PostgreSQL functions. May 6, 2015 · Then execute make_query() with a list of tables you want to display like this: SELECT make_query(ARRAY['tbl_a', 'tbl_b']); The result is that you will now have a function called name() which you can call in order to see the results of both tables at the same time, with all the union details already sorted out: SELECT * FROM name(); Also worth noting that from within a function (if it is really needed in this case) one cannot split the output to separate files (well, no file handling at all, unless one goes pl/python or something). TestMe AS BEGI Both stored procedures and user-defined functions are created with CREATE FUNCTION statement in PostgreSQL. – Oct 31, 2024 · To run multiple dynamic queries in a PostgreSQL function, you can use the EXECUTE command along with string concatenation to build and execute the SQL queries dynamically within the function. Apr 4, 2003 · The rows that it returns are defined by the group by query in its body. The equivalent of this mssql-query (note: simple example - far more complex queries): CREATE PROCEDURE dbo. May 20, 2015 · If one function substantially alters data in a table the next function is working with, the next function might base its query plan on outdated information. kflfijq fyuhbl fzjewe ezxvdo pdqy fhxqqe vjg cqxk jua qtlqxn ghw clewsy oindmn worj zixwma