Question

I have two tables. One table contains words. Other table contains points.

table words:

id word


table points:

id wordid x y 

word column is unique.

i want to write stored procedure which takes on input current x value and list of word|y values.

For example:

It’s initial words table rows:

id word
1  Carrot
2  Apple
3  Potato

We call procedure StoreData(x = 5, words = { Carrot:123, Onion:321 }).

As a result we have:

Words table:

  id word
  1  Carrot
  2  Apple
  3  Potato
  4  Onion 


Points table:    
id wordid x  y 
1    1    5 123 
2    4    5 321

How to do it?

Answer 1

You can’t pass structured data as a parameter to a stored procedure: you would have to first insert it into a (temporary) table somewhere, then read the contents of that table from within your procedure. As such, you may as well just insert directly into your destination tables:

INSERT IGNORE INTO Words (word) VALUES ('Carrot'), ('Onion');

INSERT INTO Points (wordid, x, y)
  SELECT Words.id, 5, y
  FROM   Words NATURAL JOIN (
      SELECT 'Carrot' AS word, 123 AS y
    UNION ALL
      SELECT 'Onion'  AS word, 321 AS y
  ) AS t;

See it on sqlfiddle.

(Incidentally, my materialised table t is essentially the table you’d have to create and populate before calling your stored procedure):

DELIMITER ;;
CREATE PROCEDURE StoreData(IN x INT) BEGIN
  INSERT IGNORE INTO Words SELECT word FROM args;
  INSERT IGNORE INTO Points (wordid, x, y)
    SELECT Words.id, 5, y FROM Words NATURAL JOIN args;
END;;
DELIMITER ;

DROP   TEMPORARY TABLE IF EXISTS args;
CREATE TEMPORARY TABLE args (word VARCHAR(20), y INT);
INSERT INTO args VALUES ('Carrot', 123), ('Onion', 321);
CALL StoreData(5);