So I have two tables like this...
ext_words
-------------
| id | word |
-------------
| 1 | this |
-------------
| 2 | that |
-------------
| 3 | this |
-------------
ext_words_count
---------------------
| id | word | count |
---------------------
| 1 | this | 2 |
---------------------
| 2 | that | 1 |
---------------------
I am trying to create a trigger that will:
ext_words_count.count
when ext_words.word
is updated. To further complicate matters,
ext_words.word
does not exist in ext_words_count
when ext_words
is updated, I would like to insert it into ext_words_count
and set count
as 1.I have been looking at similar questions:
1. Before / after insert trigger using auto increment field, and
2. Using Trigger to update table in another database
trying to combine the 2. Here is what I have so far:
DELIMITER $$
CREATE TRIGGER update_count
AFTER UPDATE ON ext_words
FOR EACH ROW
BEGIN
UPDATE ext_words_count
SET word_count = word_count + 1
WHERE word = NEW.word;
END;
$$
DELIMITER ;
Any advice and direction is greatly appreciated. Or possibly another method that I have overlooked and as always thanks in advance!
UPDATE:
I have opted for using 2 triggers, one for INSERT and one for UPDATE because I am not that familiar with conditional statements in MySQL.
DELIMITER $$
CREATE TRIGGER insert_word AFTER INSERT ON ext_words
FOR EACH ROW
BEGIN
INSERT IGNORE INTO ext_words_count (word) VALUES (NEW.word);
END;
$$
DELIMITER ;
and
DELIMITER $$
CREATE TRIGGER update_word AFTER UPDATE ON ext_words
FOR EACH ROW
BEGIN
UPDATE ext_words_count
SET word_count = word_count + 1
WHERE word = NEW.word;
END;
$$
DELIMITER ;
The INSERT query is working great, however the UPDATE query is not updating word_count
. Is there something I missed in the update query..?
With Grijesh's perfect help and his suggestion to use conditional statements, I was able to get ONE trigger that does both tasks. Thanks again Grijesh
DELIMITER $$
CREATE TRIGGER update_count AFTER INSERT ON ext_words
FOR EACH ROW
BEGIN
IF NOT EXISTS (SELECT 1 FROM ext_words_count WHERE word = NEW.word) THEN
INSERT INTO ext_words_count (word) VALUES (NEW.word);
ELSE
UPDATE ext_words_count SET word_count = word_count + 1 WHERE word = NEW.word;
END IF;
END $$
DELIMITER;