Is there a way to create postgres stored function (using plpgsql to be able to set input parameters) that returns a custom data set?
I've tried to do something like this according to official manual:
CREATE FUNCTION extended_sales(p_itemno int)
RETURNS TABLE(quantity int, total numeric) AS $$
BEGIN
RETURN QUERY SELECT quantity, quantity * price FROM sales
WHERE itemno = p_itemno;
END;
$$ LANGUAGE plpgsql;
but result is an array with only one column which contains type (quantity, total), but I need to get two column array with 'quantity' column and 'total' column.
At a guess you're running:
SELECT extended_sales(1);
This will return a composite type column. If you want it expanded, you must instead run:
SELECT * FROM extended_sales(1);
Also, as #a_horse_with_no_name notes, a PL/pgSQL function is completely unnecessary here. Presumably this is a simplified example?
In future please include:
Your PostgreSQL version; and
The exact SQL you ran and the exact output you got
Related
I am trying to write a BigQuery SQL function / stored procedure / table function that accepts as input:
a INT64 filter for the WHERE clause,
a table name (STRING type) as fully qualified name e.g. project_id.dataset_name.table_name
The idea is to dynamically figure out the table name and provide a filter to slice the data to return as a table.
However if try to write a Table Function (TVF) and I use SET to start dynamically writing the SQL to execute, then I see this error:
Syntax error: Expected "(" or keyword SELECT or keyword WITH but got keyword SET at [4:5]
If I try to write a stored procedure, then it expects BEGIN and END and throws this error:
Syntax error: Expected keyword BEGIN or keyword LANGUAGE but got keyword AS at [3:1]
If I try to add those, then I get various validation errors basically because I need to remove the WITH using CTEs (Common Table Expression), and semicolons ; etc.
But what I am really trying to do is using a table function:
to combine some CTEs dynamically with those inputs above (e.g. the input table name),
to PIVOT that data,
to then eventually return a table as a result of a SELECT.
A bit like producing a View that could be used in other SQL queries, but without creating the view (because the slice of data can be decided dynamically with the other INT64 input filter).
Once I dynamically build the SQL string I would like to EXECUTE IMMEDIATE that SQL and provide a SELECT as a final step of the table function to return the "dynamic table".
The thing is that:
I don't know before runtime the name of this table.
But I have all these tables with the same structure, so the SQL should apply to all of them.
Is this possible at all?
This is the not-so-working SQL I am trying to work around. See what I am trying to inject with %s and num_days:
CREATE OR REPLACE TABLE FUNCTION `my_dataset.my_table_func_name`(num_days INT64, fqn_org_table STRING)
AS (
-- this SET breaks !!!
SET f_query = """
WITH report_cst_t AS (
SELECT
DATE(start) as day,
entity_id,
conn_sub_type,
FROM `%s` AS oa
CROSS JOIN UNNEST(oa.connection_sub_type) AS conn_sub_type
WHERE
DATE(start) > DATE_SUB(CURRENT_DATE(), INTERVAL num_days DAY)
AND oa.entity_id IN ('my-very-long-id')
ORDER BY 1, 2 ASC
),
cst AS (
SELECT * FROM
(SELECT day, entity_id, report_cst_t FROM report_cst_t)
PIVOT (COUNT(*) AS connection_sub_type FOR report_cst_t.conn_sub_type IN ('cat1', 'cat2','cat3' ))
)
""";
-- here I would like to EXECUTE IMMEDIATE !!!
SELECT
cst.day,
cst.entity_id,
cst.connection_sub_type_cat1 AS cst_cat1,
cst.connection_sub_type_cat2 AS cst_cat2,
cst.connection_sub_type_cat3 AS cst_cat3,
FROM cst
ORDER BY 1, 2 ASC
);
This might not be satisfying but since Procedural language or DDL are not allowed inside Table functions currently, one possible way around would be simply using PROCEDURE like below.
CREATE OR REPLACE PROCEDURE my_dataset.temp_procedure(filter_value INT64, table_name STRING)
BEGIN
EXECUTE IMMEDIATE FORMAT(CONCAT(
"SELECT year, COUNT(1) as record_count, ",
"FROM %s ",
"WHERE year = %d ",
"GROUP BY year ",
"; "
), table_name, filter_value);
END;
CALL my_dataset.temp_procedure(2002, 'bigquery-public-data.usa_names.usa_1910_current');
I am trying to write a stored procedure in AWS Redshift SQL and one of my parameters needs the possibility to have an integer list (will be using 'IN(0,100,200,...)' inside there WHERE clause). How would I write the input parameter in the header of the procedure so that this is possible (if at all?)
I've tried passing them in as a VARCHAR "integer list" type thing but wasn't sure then how to parse that back into ints.
Update: I found a way to parse the string and loop through it using the SPLIT_PART function and store all of those into a table. Then just use a SELECT * FROM table with the IN() call
What I ended up doing was as follows. I took in the integers that I was expecting as a comma-separated string. I then ran the following on it.
CREATE OR REPLACE PROCEDURE test_string_to_int(VARCHAR)
AS $$
DECLARE
split_me ALIAS FOR $1;
loop_var INT;
BEGIN
DROP TABLE IF EXISTS int_list;
CREATE TEMPORARY TABLE int_list (
integer_to_store INT
);
FOR loop_var IN 1..(REGEXP_COUNT(split_me,',') + 1) LOOP
INSERT INTO int_list VALUES (CAST(SPLIT_PART(split_me,',',loop_var) AS INT));
END LOOP;
END;
$$ LANGUAGE plpgsql;
So I would call the procedure with something like:
CALL test_string_to_int('1,2,3');
and could do a select statement on it to see all the values stored into the table. Then in my queries the need this parameter I ran:
.........................
WHERE num_items IN(SELECT integer_to_store FROM int_list);
I am having problems defining the record's fields as case sensitive in my PostgreSQL stored procedure. I define my record as:
CREATE TYPE json_record AS (
"objectType" text ,
"objectSubtype" text
};
The reason why I need the the fields to be case sensitive is because the record is populated from JSON in stored procedure and I have no control over JSON content
My stored procedure is:
CREATE OR REPLACE FUNCTION record(id uuid, json_in json) RETURNS void AS $$
DECLARE
raw_record json_record;
BEGIN
SELECT json_populate_record( NULL::json_record, json_in) INTO raw_record;
INSERT INTO my_resource (uuid, type, subtype)
SELECT (id, raw_record.objectType, raw_record.objectSubtype);
END;
$$ LANGUAGE plpgsql VOLATILE;
When I execute the procedure I am getting the error:
ERROR: record "raw_record" has no field "objecttype"
I understand the cause of the error: the "json_record" is defined with the case sensitive fields, but PostgreSQL's execution engine converted raw_record.objectType and raw_record.objectSubtype to raw_record.objecttype and raw_record.objectsubtype. The question is how to avoid this situation and force record's fields to be treated as case sensitive. The only solution I can think of is to use dynamic SQL, build the query piece by piece and wrap the fields in quote_ident(), but I am wondering if there a simpler solution to enforce case sensitivity for a record?
force record's fields to be treated as case sensitive
The same way you always use case-sensitive identifiers: you need to enclose them in double quotes. You also don't really need a SELECT clause for the insert:
INSERT INTO my_resource (uuid, type, subtype)
VALUES (id, raw_record."objectType", raw_record."objectSubtype");
As a side note: select (a,b,c) does not what you think it does. It selects a single column that is an anonymous record (with three fields). It does not select three columns. So if you do want to stick with the select version instead of values, you have to remove the parentheses:
INSERT INTO my_resource (uuid, type, subtype)
SELECT id, raw_record."objectType", raw_record."objectSubtype";
I'm migrating some procedures from PostgreSQL to a new DB2 environment. I've got most of it done but I can't find a way to DECLARE a variable for an internal rowset/record.
Basically what the procedure does on Postgres is this:
DECLARE
counts RECORD;
BEGIN
-- fill "counts" with one row of aggregated data
SELECT
COUNT(....) AS failed_inserts,
COUNT(....) AS failed_updates,
COUNT(....) AS failed_deletes,
INTO counts
FROM (...)
-- check "counts" with some conditionals
IF counts.failed_inserts > 0
(...)
END IF;
(...)
-- return info depending on the data
RETURN (...);
END
I can't find an equivalent to declaring "counts" in the IBM manuals or elsewhere online. The row I need is static (3 columns of aggregated data). So it would be enough to declare that row hardcoded if that is possible.
Is it possible to DECLARE a record / dataset / "virtual table" within a Stored Procedure on the DB2?
We're using DB2 for Linux (V10.5) not DB2 for iSeries.
#mustaccio's answer points to the correct solution:
Outside of the procedure create the needed rowtype:
CREATE TYPE empRow AS ROW (failed_inserts INTEGER, failed_updates INTEGER, failed_deletes INTEGER);
Then you can DECLARE the new type within the procedure
DECLARE newRow empRow;
Not sure I fully understand what you want, but may be you're looking for the ROW data type? Something like this:
DECLARE
TYPE counts_row AS ROW (
failed_inserts INT,
failed_updates INT,
failed_deletes INT
);
counts counts_row;
BEGIN
-- fill "counts" with one row of aggregated data
SELECT
COUNT(....) AS failed_inserts,
COUNT(....) AS failed_updates,
COUNT(....) AS failed_deletes,
INTO counts
FROM (...);
...
PS. Not tested.
More info in the manual.
In lieu of creating a permanent** user defined type that is more or less specific to a single query, you can also achieve the same by using the FOR statement:
FOR counts AS c1 CURSOR FOR SELECT COUNT(.....) AS failed_inserts,
COUNT(....) AS failed_updates,
COUNT(....) AS failed_deletes,
FROM (...)
DO
IF counts.failed_inserts > 0 THEN
(....)
END IF;
END FOR;
** Permanent meaning something that's defined in the system catalog.
I am trying to find the minimum value of a primary key column of type (int) in a particular Table
A portion of my Stored Procedure Code:
IF NOT EXISTS
(
SELECT *
FROM Table
)
BEGIN
SELECT *
FROM Table
END
ELSE
BEGIN
SELECT Min(ColumnOne)
FROM Table
END
This is my main code after reading:
if (!reader.Read())
return "EMPTY TABLE";
else
return reader.GetInt32(0).ToString();
My ExecuteReader has no problem but when I got an exception at the statement
reader.GetInt32(0).ToString()
I believe I extract the information wrongly when my tables have more than one entry. What is the correct function I should call from reader to get the number??
i didn't get your Question.
AS you specify min() Value in Question And you wrote max() Function in T-SQL Script.
You Can try below if you want to retrieve next Val of a Column
Select isnull(max(ColumnOne),0)+1 FROM Table
Above Query will return you
1 in case Table is empty
else max current Value+1(Next Available Value)
from Table.