I've to write some MsSQL procedures and functions into DB2 procedures and functions.
Now I've the problem, that i can not use a temp table in a function with begin atomic.
Is there an other method to use a temp table in DB2 functions?
CREATE OR REPLACE FUNCTION abc( )
RETURNS TABLE (test INTEGER)
LANGUAGE SQL
MODIFIES SQL DATA
NO EXTERNAL ACTION
NOT DETERMINISTIC
BEGIN atomic
DECLARE GLOBAL TEMPORARY TABLE SESSION.StringParts (indexNumber int, stringPart nvarchar(4000)) ON COMMIT DELETE ROWS NOT LOGGED WITH REPLACE;
END
Db2-LUW up to (and including) version 11.5 has limitations on usage of DGTT (Declare Global Temporary Table) in RETURNS TABLE functions, according to the documentation.
You cannot use being atomic with declare global temporary table (i.e. that statement is not supported currently in Compound SQL(inlined) blocks).
If you use MODIFIES SQL DATA then it has limitations on Compound SQL(compiled) for table functions, it works for scalar functions.
It may be better to use SQL PL stored procedures instead of table functions in this case.
You can also circumvent some limitations if you use pipelined functions, and CGTTs can help in some cases.
Related
I'm fairly new to stored procedure. I have to design a stored procedure for ATOMIC insert (Mass insert). I'm using COBOL program to call the stored procedure in DB2. I will store values in array and have to insert all at one shot. Below is the query we are using in COBOL program and which I have to convert to stored procedure.
INSERT INTO TABLE_NAME
(COLUMN1
,COLUMN2
,COLUMN3
,COLUMN4
,COLUMN5)
VALUES
(VALUE1
,VALUE2
,VALUE3
,VALUE4
,VALUE5)
FOR WS-SUB ROWS
ATOMIC
VALUE1,VALUE2,VALUE3,VALUE4,VALUE5 are array elements and WS-SUB is number of occurrence.
I want to know, If I can handle array in stored procedure or want to know if its possible to do ATOMIC insert in DB2 stored procedure.
Thanks in advance.
Following the documentation for DB2 on z/OS 12.0.0:
A DB2 Stored Procedure may be configured to use arrays as parameter types, see Example of using arrays in an SQL procedure.
However, if your intention is calling this from COBOL you may run into issues as the documentation for Supported SQL data types in COBOL embedded SQL applications indicates:
Arrays are not supported by the COBOL precompiler
Another approach would be to pass your data as something like a CLOB or VARCHAR delimited by a character and then parse it within your stored procedure.
By default DB2 Stored Procedures does not commit on return, so another option would be to iterate your COBOL tables and call the stored procedure repeatedly.
I am trying to pass a collection of Employee objects from Java code to a DB2 Stored Procedure. In SQL server I can do that by making use of Table-Valued Parameters. In DB2 how can I achieve this?
Refer to Invoking stored procedures with ARRAY of ROW parameters in JDBC applications.
Or use Declared Global Temporary Table creating it and inserting rows into it beforehand and use this DGTT in your SP as ordinary table.
We are planning to create a procedure for our logic what should be in PL SQL in redshift (using workbench).
Can we use a table variable to traverse through the rows of the table ? Like we have dataframe in Python.
Sort of. Redshift implements a RECORD data type for stored procedures. Variables with this type can hold an arbitrary sets of rows.
"Overview of stored procedures in Amazon Redshift" > "Record types"
However, note that you cannot currently SELECT from a RECORD typed variable, only loop over the content.
There are several examples of using a RECORD variable in our GitHub repository: "amazon-redshift-utils/src/StoredProcedures/"
(1) When you open multiple cursors in a stored procedure, and then use a JDBC callable statement to iterate through the result sets, each in turn, are the order in which they are returned the same order in which they cursors are opened in the stored procedure? Or reverse of that? Or....?
(2) Is there a way to specify by sequence number or name which result set to process first?
For 1: The order of returned resultsets is undefined for JDBC, so it will depend on your actual database system. That said, it would be highly illogical for a stored procedure to return results in a different order than the order they are produced by the stored procedure.
For 2: Once again, this is not defined by JDBC. However I haven't heard of database systems that would allow you to control the order of returned results by any means other than their order in the stored procedure.
I thought I would use a stored routine to clean up some of my more complex SQL statements. From what I've read, it seems impossible to use a stored procedure within an sql statement, and a stored function only returns a single value when what I need is a result set. I am using mySQL v5.0
SELECT p.`id`, gi.`id`
FROM `sport`.`players` AS p JOIN `sport`.`gameinstances` AS gi
ON p.`id` = gi.`playerid`
WHERE (p.`playerid` IN (CALL findPlayers`("Canada", "2002")))
AND (gi.`instanceid` NOT IN (CALL findGameInstances`("Canada", "2002")));
For example, the procedures 'findPlayers' and 'findGameInstances' are are stored routines that execute some SQL and return a result set. I would prefer not to include their code directly within the statement above.
I don't know if mysql can use any of these techniques, but in SQl server I would try one of two different things (at least it might give you something to look for in th emysql documentation):
First a table values used defined function then join to that
Second, insert the results set of the sp into a temp table then join to the tem table
You could also consider putting the complicated logic in a view and then just adding the where clause after joining to the view. This won't work if your stored proc does dynamic things a view can't do, but it is a possibilty.