I've been trying to use the following query
IF EXISTS (SELECT id FROM users WHERE id = 1)
THEN
(INSERT INTO users (id, username) VALUES (2, user2))
ELSE
(UPDATE users SET username = 'userUpdated')
But I keep getting
/* SQL Error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'INSERT INTO users (id) VALUES (2)) ELSE (UPDATE users SET id = 11)' at line 1 */
Also tried using the following query
IF EXISTS (SELECT id FROM users WHERE id = 1)
THEN
(SELECT username FROM users WHERE id = 1)
ELSE
(INSERT INTO users (id, username) VALUES (1, 'user'))
But this time I got
/* SQL Error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ELSE
(INSERT INTO users (id, username) VALUES (1, 'user'))' at line 4 */
Am I doing or understood something wrong?
The if statement can only be used in programming blocks, such as stored procedures, functions, and triggers.
In any case, MySQL offers simpler syntax for this functionality: insert . . . on duplicate key update.
To use it, id must have a unique index, unique constraint, or be defined as the primary key. Let me assume that a column so-named is already so-defined.
Then:
INSERT INTO users (id, username)
VALUES (2, user2)
ON DUPLICATE KEY UPDATE username = 'userUpdated';
Are you missing the END IF (and semi colons)?
IF EXISTS (SELECT id FROM users WHERE id = 1)
THEN
(SELECT username FROM users WHERE id = 1);
ELSE
(INSERT INTO users (id, username) VALUES (1, 'user'));
END IF;
Try This.
IF EXISTS (SELECT id FROM users WHERE id = 1)
begin
INSERT INTO users (id, username) VALUES (2, 'user2')
end
ELSE
UPDATE users SET username = 'userUpdated'
In MariaDB 10.1 and newer, you can use compound statements outside of stored procedures. This blog post gives a good description of what you can do with it.
Here's an example the blog:
BEGIN NOT ATOMIC
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK;
RESIGNAL;
END;
START TRANSACTION;
stmt1;
....
stmtN;
COMMIT;
END
I want to create a trigger that only inserts into table when the condition is met.
I've tried using various combinations of IF/BEGIN/END and WHERE, but Django returns me an SQL syntax error each time.
Here, type_user_id refers to the person who triggers the like, and user_id refers to the person who receives the notification. It should only trigger when they are not the same person.
operations = [
migrations.RunSQL(
"DROP TRIGGER like_notification",
"""
CREATE TRIGGER like_notification AFTER INSERT ON user_likes_article
FOR EACH ROW
IF (select user_id from channel WHERE channel_id IN
(SELECT channel_id FROM article WHERE article_id = NEW.article_id)) <> NEW.user_id
BEGIN
INSERT INTO notification (type, type_id, article_id, is_read, type_user_id, user_id)
VALUES ('like', NEW.article_id, NEW.article_id, false, NEW.user_id,
(SELECT user_id from channel WHERE channel_id IN
(SELECT channel_id FROM article WHERE article_id = NEW.article_id)
)
)
END;
"""
)
]
>>>django.db.utils.ProgrammingError: (1064, "You have an error in your SQL syntax;
check the manual that corresponds to your MariaDB server version for the right syntax
to use near 'BEGIN\n INSERT INTO notification (type, type_id, article_id, is_re' at line 5")
and
CREATE TRIGGER like_notification AFTER INSERT ON user_likes_article
FOR EACH ROW
BEGIN
DECLARE #user_same Boolean;
SELECT 1 into #user_same
FROM channel
WHERE channel_id IN (select channel_id FROM article where article_id = NEW.article_id)
AND user_id = NEW.user_id;
IF #user_same <> 1
THEN
INSERT INTO notification (type, type_id, article_id, is_read, type_user_id, user_id,)
VALUES ('like', NEW.article_id, NEW.article_id, false, NEW.user_id, (
SELECT user_id from channel WHERE channel_id IN (
SELECT channel_id FROM article WHERE article_id = NEW.article_id)
)
END IF;
END;
>>>You have an error in your SQL syntax; check the manual that corresponds to your
MariaDB server version for the right syntax to use near '#user_same Boolean;\n SELECT 1 into #user_same\n FRO' at line 4"
and
CREATE TRIGGER like_notification AFTER INSERT ON user_likes_article
FOR EACH ROW
INSERT INTO notification (type, type_id, article_id, is_read, type_user_iduser_id)
VALUES ('like', NEW.article_id, NEW.article_id, false, NEW.user_id,
(
SELECT user_id from channel WHERE channel_id IN
(SELECT channel_id FROM article WHERE article_id = NEW.article_id)
)
WHERE NOT user_id = NEW.user_id;
>>>You have an error in your SQL syntax; check the manual that corresponds to your
MariaDB server version for the right syntax to use near 'WHERE NOT user
I don't really understand why none of them work. Any help would be much appreciated!
#variables are not DECLARED.
Either:
DECLARE user_same BOOLEAN;
SELECT 1 INTO user_same WHERE ...
or
SELECT #user_same := 1 WHERE ...
Better yet, this avoids the need for the variable.
IF (EXISTS SELECT * FROM ...)
Also, don't use the construct IN ( SELECT ... ); it is usually better to use WHERE EXISTS ( SELECT * FROM ... ) or JOIN ... ON ....
(There may be more problems after fixing those.)
Another easy way to do this.
You should add any symbols between ; delimiters for the appropriate converting MySQL syntax to the raw SQL.
CREATE TRIGGER trigger_name BEFORE INSERT ON table
FOR EACH ROW
BEGIN
IF NEW.number <> 'anynumber' AND NEW.number <> 'anynumber'
THEN
SET NEW.number = 'anynumber'; --
END IF; --
END
This example works due to the dash symbols.
I am trying to update a row if its exists, if it does not exist then I want to perform an insert into the table. The picture.id & picture.picturepath are a unique key. I have looked at some examples but I am not sure What I am doing wrong.
I have come across on duplicate key update, not sure if this is relevant to what I am trying to achieve.
Error message: 1064- You have an error in your SQL syntax near 'UPDATE picture SET picture.picturecontent = ipicturecontent WHERE picture.id at line 5"
IF EXISTS( SELECT * FROM picture WHERE picture.id = ipictureid
AND picture.picturepath = ipicturepath) THEN
UPDATE picture
SET picture.picturecontent = ipicturecontent
WHERE picture.id = ipictureid
AND picture.picturepath = ipicturepath
ELSE
INSERT INTO picture (picture.id, picture.picturecontent,picture.picturepath) VALUES (ipictureid, ipicturecontent, ipicturepath)
https://stackoverflow.com/a/10095812/1287480 <- Credit where credit is due
INSERT INTO models (col1, col2, col3)
VALUES ('foo', 'bar', 'alpha')
ON DUPLICATE KEY UPDATE col3='alpha';
don't forget THEN, BEGIN and END
IF EXISTS( SELECT * FROM picture WHERE id = ipictureid
AND picturepath = ipicturepath)
THEN
BEGIN
UPDATE picture
SET picturecontent = ipicturecontent
WHERE id = ipictureid
AND picturepath = ipicturepath
END;
ELSE
BEGIN
INSERT INTO picture (id,
picturecontent,
picturepath)
VALUES (ipictureid, ipicturecontent, ipicturepath)
END;
END IF;
Am using this sql to do an update on duplicate key
IF (SELECT COUNT(*) FROM `mlm_settings` WHERE `key` = 'notify_type' AND `user_id`=7 >0 )
UPDATE mlm_settings SET value='2' WHERE user_id = 7
ELSE
BEGIN
INSERT INTO `mlm_settings` (`key`, `value`,`user_id`) VALUES ('notify_type', '2',7)
END
by i get an sql error in mysql saying
#1064 - You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near 'IF (SELECT COUNT(*) FROM
`mlm_settings` WHERE `key` = 'notify_type' AND `user_id' at line 1
i can't figure what is the cause of the error, as the names of the tables are valid and the values are of the same data type
what could be the error?
You can only use IF statements in stored procedures, not normal queries.
If there's a unique index on (key, user_id) in the table, you can use:
INSERT INTO mlm_settings (`key`, value, user_id) VALUES ('notify_type', '2', 7)
ON DUPLICATE KEY UPDATE value = '2';
IF control block cannot be used OUTSIDE of functions. Try this:-
SELECT IF( EXISTS(
SELECT COUNT(*) FROM `mlm_settings` WHERE `key` = 'notify_type' AND `user_id`=7 >0), 1, 0)
I'm stuck here.
I've got a Procedure that I want to run X* times in a row. (*X is couple of thousands times)
The procedure based on input data does this:
1. Looks for an actions.id, if not found LEAVEs.
2. Looks for users.id, if not found, creates one and uses LAST_INSERT_ID();
3-5. Looks for summaries.id (3 types, total, daily and monthly), if not found, creates one and uses it's ID.
6. Once all required ids are collected, INSERTs new row into actions and either updates the summaries rows in a transaction, so if any fails - it does a ROLLBACK - no harm done.
7. Depending on the outcome SELECTs message.
CREATE PROCEDURE NEW_ACTION(
IN a_date TIMESTAMP,
IN u_name VARCHAR(255),
IN a_name VARCHAR(255),
IN a_chars INT,
IN url VARCHAR(255),
IN ip VARCHAR(15))
lbl_proc: BEGIN
DECLARE a_id, u_id, us_id, usd_id, usm_id, a_day, a_month, error INT;
DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET error = 1;
SET error = 0;
SET a_day = DATE_FORMAT(SUBSTRING(a_date ,1,10), '%Y%m%d');
SET a_month = SUBSTRING(a_day, 1, 6);
/* 1. RETREIVING action.id */
SET a_id = (SELECT `id` FROM `actions` WHERE `name` = a_name);
IF a_id IS NULL THEN
SELECT 'error';
LEAVE lbl_proc;
END IF;
/* 2. RETREIVING users.id */
SET u_id = (SELECT `id` FROM `users` WHERE `name` = u_name);
IF u_id IS NULL THEN
INSERT INTO `users` (name) VALUES (u_name);
SET u_id = (SELECT LAST_INSERT_ID());
END IF;
/* 3. RETREIVING user_summaries.id */
SET us_id = (SELECT `id` FROM `users_summaries` WHERE `user_id` = u_id AND `action_id` = a_id);
IF us_id IS NULL THEN
INSERT INTO `users_summaries` (user_id, action_id) VALUES (u_id, a_id);
SET us_id = (SELECT LAST_INSERT_ID());
END IF;
/* 4. RETREIVING user_summaries_days.id */
SET usd_id = (SELECT `id` FROM `users_summaries_days` WHERE `day` = a_day AND `user_id` = u_id AND `action_id` = a_id);
IF usd_id IS NULL THEN
INSERT INTO `users_summaries_days` (day, user_id, action_id) VALUES (a_day, u_id, a_id);
SET usd_id = (SELECT LAST_INSERT_ID());
END IF;
/* 5. RETREIVING user_summaries_months.id */
SET usm_id = (SELECT `id` FROM `users_summaries_months` WHERE `month` = a_month AND `user_id` = u_id AND `action_id` = a_id);
IF usm_id IS NULL THEN
INSERT INTO `users_summaries_months` (month, user_id, action_id) VALUES (a_month, u_id, a_id);
SET usm_id = (SELECT LAST_INSERT_ID());
END IF;
/* 6. SAVING action AND UPDATING summaries */
SET autocommit = 0;
START TRANSACTION;
INSERT INTO `users_actions` (`date`, `user_id`, `action_id`, `chars`, `url`, `ip`) VALUES (a_date, u_id, a_id, a_chars, url, ip);
UPDATE `users_summaries` SET qty = qty + 1, chars = chars + a_chars WHERE id = us_id;
UPDATE `users_summaries_days` SET qty = qty + 1, chars = chars + a_chars WHERE id = usd_id;
UPDATE `users_summaries_months` SET qty = qty + 1, chars = chars + a_chars WHERE id = usm_id;
IF error = 1 THEN
SELECT 'error';
ROLLBACK;
LEAVE lbl_proc;
ELSE
SELECT 'success';
COMMIT;
END IF;
END;
Now, I've got raw data that I want to feed into this procedure. There's currently about 3000 rows.
I tried all the solutions I knew:
A. # mysql -uuser -ppass DB < calls.sql - Using php I've basically created a list of calls like this:
CALL NEW_ACTION('2010-11-01 13:23:00', 'username1', 'actionname1', '100', 'http://example.com/', '0.0.0.0');
CALL NEW_ACTION('2010-11-01 13:23:00', 'username2', 'actionname1', '100', 'http://example.com/', '0.0.0.0');
CALL NEW_ACTION('2010-11-01 13:23:00', 'username1', 'actionname2', '100', 'http://example.com/', '0.0.0.0');
...
This fails always (tried few times) at row 452 where it found two summary IDs (step 3).
I thought this could be due to the fact that earlier (rows 375-376) there are calls for the same user for the same action.
As if mysql didn't update tables in time, so the summary row created in CALL from line 375 isn't yet visible when line 376 gets executed - therefore creating another summary line.
Tought I'd try delaying calls...
B. Using mysql's SLEEP(duration).
This didn't change anything. Execution stops at the very same CALL again.
I'm out of ideas now.
Suggestions and help hugely appreciated.
NOTE: action names and user names repeat.
PS. Bear in mind this is one of my first procedures ever written.
PS2. Running mysql 5.1.52-community-log 64bit (Windows 7U), PHP 5.3.2 and Apache 2.2.17
EDIT
I've removed PHP related part of question to a separate question here.
EDIT2
Ok, I've deleted the first 200 calls from the .sql file. For some reason it went fine past the previous line that was stopping execution. Now it stopped at row 1618.
This would mean, that at one point a newly INSERTed summary row is no visible for a moment, therefore when it happens that one of the following iterations want to SELECT it, it's not yet accessible for them. Is that a MySQL bug?
EDIT3
Now there's another interesting thing I noticed. I investigated where two users_summaries get created. This happens (not always, but if, then it is) when there are two CALLs referring to the same user and action in close proximity. They could be next to each other or separated by 1 or 2 different calls.
If I move one of them (within .sql file) like 50-100 rows lower (executed earlier) than it's fine. I even managed to make the .sql file work as a whole. But this still doesn't really solve the problem. With 3000 rows it's not that bad, but if I had 100000, I'm lost. I can't rely on manual tweaks to .sql file.
This isn't really a solution, but a workaround.
Just to clarify, summary tables had id column as PRIMARY KEY with AUTO_INCREMENT option and indexes on both user_id and action_id column.
My investigation showed that although my procedure was looking for an entry that existed using WHERE user_id = u_id AND action_id = a_id in certain situations it didn't find it causing new row being inserted with the same user_id and action_id values - something I did not want.
Debugging the procedure showed that the summary row I was looking for, although not accessible with WHERE user_id = u_id AND action_id = a_id condition, was properly returned when calling it's id - PRIMARY KEY.
With this find I decided to change format of id column, from UNASIGNED INT with AUTO_INCEREMENT to a CHAR(32) which consisted of:
<user_id>|<action_id>
This meant that I knew exactly what the id of the row I wanted is even before it existed. This solved the problem really. It also enabled me to use INSERT ... ON DUPLICATE KEY UPDATE ... construct.
Below my updated procedure:
CREATE PROCEDURE `NEW_ACTION`(
IN a_date TIMESTAMP,
IN u_name VARCHAR(255),
IN a_name VARCHAR(255),
IN a_chars INT,
IN url VARCHAR(255),
IN ip VARCHAR(15))
SQL SECURITY INVOKER
lbl_proc: BEGIN
DECLARE a_id, u_id, a_day, a_month, error INT;
DECLARE us_id, usd_id, usm_id CHAR(48);
DECLARE sep CHAR(1);
DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET error = 1;
SET sep = '|';
SET error = 0;
SET a_day = DATE_FORMAT(SUBSTRING(a_date ,1,10), '%Y%m%d');
SET a_month = SUBSTRING(a_day, 1, 6);
/* RETREIVING action.id */
SET a_id = (SELECT `id` FROM `game_actions` WHERE `name` = a_name);
IF a_id IS NULL THEN
SELECT 'error';
LEAVE lbl_proc;
END IF;
/* RETREIVING users.id */
SET u_id = (SELECT `id` FROM `game_users` WHERE `name` = u_name);
IF u_id IS NULL THEN
INSERT INTO `game_users` (name) VALUES (u_name);
SET u_id = LAST_INSERT_ID();
END IF;
/* SETTING summaries ids */
SET us_id = CONCAT(u_id, sep, a_id);
SET usd_id = CONCAT(a_day, sep, u_id, sep, a_id);
SET usm_id = CONCAT(a_month, sep, u_id, sep, a_id);
/* SAVING action AND UPDATING summaries */
SET autocommit = 0;
START TRANSACTION;
INSERT INTO `game_users_actions` (`date`, `user_id`, `action_id`, `chars`, `url`, `ip`)
VALUES (a_date, u_id, a_id, a_chars, url, ip);
INSERT INTO `game_users_summaries` (`id`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (us_id, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
INSERT INTO `game_users_summaries_days` (`id`, `day`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (usd_id, a_day, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
INSERT INTO `game_users_summaries_months` (`id`, `month`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (usm_id, a_month, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
IF error = 1 THEN
SELECT 'error';
ROLLBACK;
LEAVE lbl_proc;
ELSE
SELECT 'success';
COMMIT;
END IF;
END
Anyway, I still think there's some kind of a bug in MySQL, but I consider problem solved.