How can I pass an "array" of values to my stored procedure?

I want to be able to pass an "array" of values to my stored procedure, instead of calling "Add value" procedure serially.

Can anyone suggest a way to do it? am I missing something here?

Edit: I will be using PostgreSQL / MySQL, I haven't decided yet.

Upvotes: 14

Answers (7)

Kevin Barasa

Reputation: 71

Thanks to JSON support in MySQL you now actually have the ability to pass an array to your MySQL stored procedure. Create a JSON_ARRAY and simply pass it as a JSON argument to your stored procedure. Then in procedure, using MySQL's WHILE loop and MySQL's JSON "pathing" , access each of the elements in the JSON_ARRAY and do as you wish. An example here https://gist.githubusercontent.com/jonathanvx/513066eea8cb5919b648b2453db47890/raw/22f33fdf64a2f292688edbc67392ba2ccf8da47c/json.sql

Upvotes: 1

Chris Lampley

Reputation:

For PostgreSQL, you could do something like this:

CREATE OR REPLACE FUNCTION fnExplode(in_array anyarray) RETURNS SETOF ANYELEMENT AS
$$
    SELECT ($1)[s] FROM generate_series(1,array_upper($1, 1)) AS s;
$$
LANGUAGE SQL IMMUTABLE;

Then, you could pass a delimited string to your stored procedure.

Say, param1 was an input param containing '1|2|3|4|5'

The statement:

SELECT CAST(fnExplode(string_to_array(param1, '|')) AS INTEGER);

results in a result set that can be joined or inserted.

Likewise, for MySQL, you could do something like this:

DELIMITER $$
CREATE PROCEDURE `spTest_Array`
(
    v_id_arr TEXT
)
BEGIN
    DECLARE v_cur_position INT; 
    DECLARE v_remainder TEXT; 
    DECLARE v_cur_string VARCHAR(255); 
    CREATE TEMPORARY TABLE tmp_test
    ( 
        id INT
    ) ENGINE=MEMORY; 

    SET v_remainder = v_id_arr; 
    SET v_cur_position = 1;

    WHILE CHAR_LENGTH(v_remainder) > 0 AND v_cur_position > 0 DO 
        SET v_cur_position = INSTR(v_remainder, '|'); 
        IF v_cur_position = 0 THEN 
            SET v_cur_string = v_remainder; 
        ELSE 
            SET v_cur_string = LEFT(v_remainder, v_cur_position - 1); 
        END IF; 

        IF TRIM(v_cur_string) != '' THEN 
            INSERT INTO tmp_test
                (id)
            VALUES 
                (v_cur_string);                 
        END IF; 

        SET v_remainder = SUBSTRING(v_remainder, v_cur_position + 1); 
    END WHILE; 

    SELECT 
        id
    FROM 
    tmp_test;

    DROP TEMPORARY TABLE tmp_test;
END 
$$

Then simply CALL spTest_Array('1|2|3|4|5') should produce the same result set as the above PostgreSQL query.

Upvotes: 2

Weej

Reputation: 1022

I don't know about passing an actual array into those engines (I work with sqlserver) but here's an idea for passing a delimited string and parsing it in your sproc with this function.

CREATE FUNCTION [dbo].[Split]
(
    @ItemList NVARCHAR(4000), 
    @delimiter CHAR(1)
)
RETURNS @IDTable TABLE (Item VARCHAR(50))  
AS      

BEGIN    
    DECLARE @tempItemList NVARCHAR(4000)
    SET @tempItemList = @ItemList

    DECLARE @i INT    
    DECLARE @Item NVARCHAR(4000)

    SET @tempItemList = REPLACE (@tempItemList, ' ', '')
    SET @i = CHARINDEX(@delimiter, @tempItemList)

    WHILE (LEN(@tempItemList) > 0)
    BEGIN
        IF @i = 0
            SET @Item = @tempItemList
        ELSE
            SET @Item = LEFT(@tempItemList, @i - 1)
        INSERT INTO @IDTable(Item) VALUES(@Item)
        IF @i = 0
            SET @tempItemList = ''
        ELSE
            SET @tempItemList = RIGHT(@tempItemList, LEN(@tempItemList) - @i)
        SET @i = CHARINDEX(@delimiter, @tempItemList)
    END 
    RETURN
END

Upvotes: 3

MAbraham1

Reputation: 1768

Incidently, here is how you would add the array to a function (stored-proc) call:

CallableStatement proc = null;
List<Integer> faultcd_array = Arrays.asList(1003, 1234, 5678);
//conn - your connection manager
conn = DriverManager.getConnection(connection string here);
proc = conn.prepareCall("{ ? = call procedureName(?) }");
proc.registerOutParameter(1, Types.OTHER);
//This sets-up the array
Integer[] dataFaults = faultcd_array.toArray(new Integer[faultcd_array.size()]);
java.sql.Array sqlFaultsArray = conn.createArrayOf("int4", dataFaults);
proc.setArray(2, sqlFaultsArray);
//:
//add code to retrieve cursor, use the data.
//:

Upvotes: 0

user80168

Reputation:

As Chris pointed, in PostgreSQL it's no problem - any base type (like int, text) has it's own array subtype, and you can also create custom types including composite ones. For example:

CREATE TYPE test as (
    n int4,
    m int4
);

Now you can easily create array of test:

select ARRAY[
    row(1,2)::test,
    row(3,4)::test,
    row(5,6)::test
];

You can write a function that will multiply n*m for each item in array, and return sum of products:

CREATE OR REPLACE FUNCTION test_test(IN work_array test[]) RETURNS INT4 as $$
DECLARE
    i      INT4;
    result INT4 := 0;
BEGIN
    FOR i IN SELECT generate_subscripts( work_array, 1 ) LOOP
        result := result + work_array[i].n * work_array[i].m;
    END LOOP;
    RETURN result;
END;
$$ language plpgsql;

and run it:

# SELECT test_test(
    ARRAY[
        row(1, 2)::test,
        row(3,4)::test,
        row(5,6)::test
    ]
);
 test_test
-----------
        44
(1 row)

Upvotes: 9