How do I return multiple result sets in PostgreSQL?

Linked

  1. PostgreSQL function returning multiple DIFFERENT datasets.
  2. Postgres function: return multiple tables.
  3. Accessing the Return Table in a Postgres Function.
  4. Pass array of tags to a plpgsql function and use it in WHERE condition.
  5. Using results from PostgreSQL query in FROM clause of another query.

What is $$ in plpgsql?

In PostgreSQL, the dollar-quoted string constants ($$) is used in user-defined functions and stored procedures. In PostgreSQL, you use single quotes for a string constant like this: select ‘String constant’; When a string constant contains a single quote (‘), you need to escape it by doubling up the single quote.

How do I declare a variable in PostgreSQL?

PostgreSQL: Declaring Variables

  1. Syntax. The syntax to declare a variable in PostgreSQL is: DECLARE variable_name [ CONSTANT ] datatype [ NOT NULL ] [ { DEFAULT | := } initial_value ]
  2. Example – Declaring a variable.
  3. Example – Declaring a variable with an initial value (not a constant)
  4. Example – Declaring a constant.

Which statement assigns a value to plpgsql variable?

An assignment of a value to a PL/pgSQL variable is written as: variable { := | = } expression ; As explained previously, the expression in such a statement is evaluated by means of an SQL SELECT command sent to the main database engine.

Can a SQL function return multiple tables?

You can’t return two different result sets from the same procedure. If you’re going to handle the the results the same from both queries consider a UNION, INTERSECT, or MINUS. @WilliamStearns “You can’t return two different result sets from the same procedure” – that is a very incorrect statement: you can.

How do you combine two select queries in SQL with different number of columns?

The UNION operator is used to combine the result-set of two or more SELECT statements.

  1. Every SELECT statement within UNION must have the same number of columns.
  2. The columns must also have similar data types.
  3. The columns in every SELECT statement must also be in the same order.

How do I run Plpgsql?

Set Up a PostgreSQL Database on Windows

  1. Download and install a PostgreSQL server.
  2. Add the PostgreSQL bin directory path to the PATH environmental variable.
  3. Open the psql command-line tool:
  4. Run a CREATE DATABASE command to create a new database.
  5. Connect to the new database using the command: \c databaseName.

What is pattern in SQL?

SQL pattern matching enables you to use _ to match any single character and % to match an arbitrary number of characters (including zero characters). In MySQL, SQL patterns are case-insensitive by default.

Which of the following is correct syntax to declare a variable in Plpgsql?

The general syntax of a variable declaration is: name [ CONSTANT ] type [ COLLATE collation_name ] [ NOT NULL ] [ { DEFAULT | := | = } expression ];

How do you set a variable in Pgadmin?

You would use PL/pgSQL code in an anonymous block ( DO statement) or in a function. However, you can (ab)use customized options, for server-side “variables”, independent of the client in use: SET foo. test = ‘SELECT bar FROM baz’; SELECT current_setting(‘foo.

What is multi statement table valued function?

A multi-statement table-valued function or MSTVF is a table-valued function that returns the result of multiple statements. The multi-statement-table-valued function is very useful because you can execute multiple queries within the function and aggregate results into the returned table.