How to return multiple result sets in PostgreSQL?

How to return multiple result sets in PostgreSQL?

A simpler way has been around since PostgreSQL 8.3: CREATE FUNCTION test() RETURNS SETOF first_table AS $func$ BEGIN RETURN QUERY SELECT * FROM first_table; RETURN QUERY SELECT * FROM second_table; — has to return same rowtype as first_table!

How to return multiple rows from stored procedure in PostgreSQL?

Let’s make a function that returns all the rows of a table whose name you pass in as a parameter. create or replace function GetRows(text) returns setof record as ‘ declare r record; begin for r in EXECUTE ”select * from ” || $1 loop return next r; end loop; return; end ‘ language ‘plpgsql’;

How to return result Set in stored procedure in PostgreSQL?

Both stored procedures and user-defined functions are created with CREATE FUNCTION statement in PostgreSQL. To return one or more result sets (cursors in terms of PostgreSQL), you have to use refcursor return type.

Can Postgres stored procedure return table?

PostgreSQL returns a table with one column that holds the array of films. In practice, you often process each individual row before appending it in the function’s result set.

How do I store multiple records in PostgreSQL?

PostgreSQL INSERT Multiple Rows

1. First, specify the name of the table that you want to insert data after the INSERT INTO keywords.
2. Second, list the required columns or all columns of the table in parentheses that follow the table name.
3. Third, supply a comma-separated list of rows after the VALUES keyword.

Can we call stored procedure from function in PostgreSQL?

Traditionally, PostgreSQL has provided all the means to write functions (which were called as stored procedures) however, in a function you cannot run transactions. The new CREATE PROCEDURE will change all that and provide a functionality to run transactions inside procedural code.

Can we call a procedure inside a function in PostgreSQL?

You cannot execute a stored procedure inside a function, because a function is not allowed to modify database state, and stored procedures are allowed to modify database state.

To return multiple result sets, specify SETOF refcursor return type and use RETURN NEXT to return each cursor: Processing the result sets and designing the procedures returning result sets may depend on the caller. Let’s assume you need to call a procedure and output the result set in PSQL tool, pgAdmin Query tool or another function:

How to return a result set from a stored procedure?

PostgreSQL – How to Return a Result Set from a Stored Procedure Both stored procedures and user-defined functions are created with CREATE FUNCTION statement in PostgreSQL. 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.

Do you have to return NULL in PostgreSQL?

If a RETURN statement is desired to exit the code early, then NULL must be returned. Returning any other value will result in an error. You could mark your parameters as output though, so that they would behave like variables.

How to get rows in PostgreSQL by transaction?

To get the rows you need to use FETCH statement and specify the cursor name: The problem is that the cursor already closed, as we did not use a transaction. Let’s start a transaction, execute the procedure, and fetch rows again:

How to pass multiple rows to PostgreSQL function?

PostgreSQL doesn’t have table-valued variables (yet), so nothing’s going to be pretty. Passing arrays is inefficient but will work for reasonable-sized inputs. For bigger inputs, what often works is to pass a refcursor. It’s clumsy, but can be practical for larger data sets, sometimes combined with temp tables.

What does function do in PostgreSQL query language?

Query Language ( SQL ) Functions SQL functions execute an arbitrary list of SQL statements, returning the result of the last query in the list. In the simple (non-set) case, the first row of the last query’s result will be returned.

Is it possible to pass arrays to PostgreSQL?

Passing arrays is inefficient but will work for reasonable-sized inputs. For bigger inputs, what often works is to pass a refcursor. It’s clumsy, but can be practical for larger data sets, sometimes combined with temp tables. Not beautiful. But then, plpgsql never is.

When does the cursor close in PostgreSQL?

Important Note: The cursor remains open until the end of transaction, and since PostgreSQL works in auto-commit mode by default, the cursor is closed immediately after the procedure call, so it is not available to the caller. To work with cursors the caller have to start a transaction.