I'm in my first databases class and I'm trying to write a conditional block for a mysql procedure.
This is the procedure:
delimiter //
CREATE PROCEDURE add_ascent(IN cid INT, IN pid INT)
BEGIN
DECLARE count_ascents INT;
SET count_ascents = 0;
SELECT COUNT(`cid`) INTO count_ascents FROM ascents WHERE `cid`=cid AND `pid`=pid;
IF count_ascents < 1 THEN
INSERT INTO ascents (`cid`, `pid`) VALUES (cid, pid);
UPDATE climbers SET climbers.ascents = climbers.ascents + 1 WHERE climbers.id=cid;
UPDATE problems SET problems.ascents = problems.ascents + 1 WHERE problems.id=pid;
END IF;
END;
//
delimiter ;
The goal of the procedure is to only perform the insert and updates if the (cid, pid) pair is not in the the ascents database. After testing, the program doesn't seem to go into the if block at all.
FYI, you might want to consider using an UPSERT, instead of "select/if/insert". For example, mySQL offers INSERT ON DUPLICATE KEY UPDATE.
Here, I suggest:
giving your parameters a DIFFERENT name than the column name, for example iCid and iPid, then
Typing SELECT COUNT(cid) INTO count_ascents FROM ascents WHERE cid=iCid AND pid=iPid and checking the result.
Related
Why is the data not being inserted on the table when I execute the procedure, what seems to be lacking with the code?
I'm testing the procedure on phpMyAdmin > myDatabase > Procedures "Routines Tab" and clicking "Execute", prompts with a modal and ask for the values of "#idproc and #nameproc.
I tried with just the INSERT code it works, but when I add the IF condition it doesn't work.
Using XAMPP 8.0.3,
10.4.18-MariaDB
DELIMITER $$
CREATE DEFINER=`root`#`localhost:3307` PROCEDURE `testproc`(IN `idproc` INT, IN `nameproc` VARCHAR(100))
BEGIN
IF #idproc = 0 THEN
INSERT INTO testproc(
id,
name)
VALUES(
#idproc,
#nameproc
);
ELSE
UPDATE testproc
SET
id = #idproc,
name = #nameproc
WHERE id = #idproc;
END IF;
SELECT * FROM testproc;
END$$
DELIMITER ;
You mix local variables (their names have not leading #) and user-defined variables (with single leading #). This is two different variable types, with different scopes and datatype rules. Procedure parameters are local variables too.
So when you use UDV which was not used previously you receive NULL as its value - and your code works incorrectly. Use LV everywhere:
CREATE DEFINER=`root`#`localhost:3307`
PROCEDURE `testproc` (IN `idproc` INT, IN `nameproc` VARCHAR(100))
BEGIN
IF idproc = 0 THEN
INSERT INTO testproc (name) VALUES (nameproc);
ELSE
UPDATE testproc SET name = nameproc WHERE id = idproc;
END IF;
SELECT * FROM testproc;
END
You do not check does specified idproc value exists in the table. If it is specified (not zero) but not exists then your UPDATE won't update anything. Assuming that id is autoincremented primary key of the table I recommend to use
CREATE DEFINER=`root`#`localhost:3307`
PROCEDURE `testproc` (IN `idproc` INT, IN `nameproc` VARCHAR(100))
BEGIN
INSERT INTO testproc (id, name)
VALUES (idproc, nameproc)
ON DUPLICATE KEY
UPDATE name = VALUES(name);
SELECT * FROM testproc;
END
If specified idproc value exists in id column the row will be updated, if not then the new row will be inserted.
Additionally - I recommend you to provide NULL value instead of zero when you want to insert new row with specified nameproc value. NULL always cause autoincremented primary key generation whereas zero needs in specific server option setting.
I did a trigger in mysql to shoot alerts always an input value was less than the set value. But now I need it is done in SQL SERVER.
I would be grateful if someone could help me transform mysql trigger to a SQL Server trigger.
Thanks to all at once.
My trigger is:
DELIMITER $$
create TRIGGER alert
AFTER INSERT ON records
FOR EACH ROW
begin
Set #comp=0;
Set #tempmax=0;
Set #tempmin=0;
select lim_inf_temp into #tempmin from sensores where idSensor=NEW.idSensor;
Set #maxidAlarme=0;
if (CAST(NEW.Temperatura AS UNSIGNED)<#tempmin) then
SELECT MAX(idAlarme) into #maxidAlarme FROM alarmes;
SET #maxidAlarme=#maxidAlarme+1;
INSERT INTO alarmes(idAlarme,descricao_alarme, idRegisto) VALUES (#maxidAlarme,"inserted below the normal temperature",New.idRegisto);
INSERT INTO sensores_tem_alarmes(idSensor,idAlarme,dataAlarme) VALUES (NEW.idSensor,#maxidAlarme,NOW());
set #comp=+1;
end if;
set #id_sensores_em_alerta=1;
SELECT MAX(id_sensores_em_alerta) into #id_sensores_em_alerta FROM sensores_em_alerta;
INSERT INTO sensores_em_alerta(id_sensores_em_alerta, idSensor, idAlarme, data_registo, numerosensoresdisparados) VALUES (id_sensores_em_alerta,NEW.idSensor, #maxidAlarme, NOW(), #comp);
end $$;
DELIMITER ;
I've tried to make the trigger in SQL Server, but as the script is different and I'm getting many difficulties to do the right way.
My attempt that was not going at all well:
CREATE TRIGGER Alert ON registos AFTER INSERT AS
BEGIN
DECLARE #comp decimal= 0
DECLARE #tempmax decimal= 0
DECLARE #tempmin decimal= 0
DECLARE #current_max_idAlarme int = (SELECT MAX(IdAlarme) FROM alarmes)
-- Insert into alarmes from the inserted rows if temperature less than tempmin
INSERT alarmes (IdAlarme, descricao_alarme, idRegisto)
SELECT
ROW_NUMBER() OVER (ORDER BY i.idRegisto) + #current_max_idAlarme,
'temp Error',
i.idRegisto
FROM
inserted AS i
WHERE
i.Temperatura < #tempmin
END
But dont do anything.
Dont create data on table alarmes :S
Does anyone could help me please. I would be eternally grateful.
Many Greetings and thank you all.
First of all, MSSQL doesn't have the option FOR EACH ROW, so it treats multiple inserted rows at once as a set. You will therefore have to insert the values into a table variable.
Unfortunately I do not know much MySQL actually, but I believe this is a starting point?
CREATE TRIGGER ALERT
ON records
AFTER INSERT
AS
BEGIN
DECLARE #comp INT;
DECLARE #tempmax INT;
DECLARE TABLE #tempmin (tempmin INT);
INSERT INTO #tempmin
SELECT s.lim_inf_temp FROM sensores s WHERE s.idSensor IN (inserted.idSensor);
--rest of the code
I'm going to post this code against my better judgement - redesign the tables is better than this hack.
This uses a ROW_number() to virtualise a surrogate identity key for the alarmes table. This is a 'bad plan' (tm).
Also the answer is partial - it doesn't do everything your question asked for -- I hope it gets your further along the road. Use it as a guide for how to interact with the virtual INSERTED table. Good luck
CREATE TRIGGER Alert ON records AFTER INSERT AS
BEGIN
DECLARE #comp INT = 0
DECLARE #tempmax INT = 0
DECLARE #tempmin INT = 0
-- get the max current id.
-- note that this is EXTREMELY unsafe as if two pieces of code are executing
-- at the same time then you *will* end up with key conflicts.
-- you could use SERIALIZABLE.... but better would be to redisn the schema
DECLARE #current_max_idAlarme = (SELECT MAX(IdAlarme) FROM alarmes)
-- Insert into alarmes from the inserted rows if temperature less than tempmin
INSERT alarmes (IdAlarme, descricao_alarme, idRegisto)
SELECT
ROW_NUMBER() OVER (ORDER BY i.idRegisto) + #current_max_idAlarme,
'temp Error',
i.idRegisto
FROM
inserted AS i
WHERE
i.Temperatura < #tempmin
END
How do I write a stored procedure to add a person record with multiple addresses?
It is easy if the person has only one address but I'm not sure how to write a stored procedure to add a person with multiple addresses.
Here is the stored procedure to add a person with one address:
DELIMITER $$
CREATE PROCEDURE `log`.`spAddPerson` (
IN personID INT,
IN personName VARCHAR(100),
IN addressLine1 VARCHAR(45),
IN addressLine2 VARCHAR(45),
IN myCity VARCHAR(45),
IN myState VARCHAR(45),
IN myCountry VARCHAR(45)
)
BEGIN
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK;
END;
START TRANSACTION;
INSERT INTO person VALUES(personID,personName);
-- addressid is automatically generated
INSERT INTO address(Line1, Line2,City,State,Country) VALUES
(addressLine1, addressLine2, myCity,myState, myCountry);
INSERT INTO personAddress(personID, last_insert_id());
COMMIT;
END
The above code works fine. However, I do not know how to handle a person with multiple addresses without writing a separate stored procedure. Is there a simple way to do this?
You cannot pass a variable number of variables to a procedure, nor a non-scalar type.
A possible trick would be building a temporary table with the addresses before calling this procedure. Either the temporary table is pre-determined, or pass its name as a VARCHAR parameter(and use it to build dynamic SQL statements). Eg:
CREATE PROCEDURE spAddPerson (tmp_table VARCHAR(10), ...)
BEGIN
...
PREPARE s AS CONCAT(
'INSERT INTO address (line1, ...) VALUES SELECT * FROM ', tmp_table
);
EXECUTE s;
...
END
-- use it like this
CREATE TEMPORARY TABLE tmp_addresses (line1 VARCHAR(255), ...);
INSERT INTO tmp_addresses VALUES ('1 Cherry Lane'), ... ;
CALL spAddPerson ('tmp_addresses', ...);
However, I would rather split the action in two parts. Do you really want to prevent the creation of the person altogether if its address creation fails? And even then, wouldn't you want to advise your user why the transaction failed (user creation or address creation)?
I would rather treat these two exceptions separately at the application level:
issue a "START TRANSATION"
try to insert a person (call stored proc 1)
if it failed, rollback and notify user
for each address
try to insert an address (call stored proc 2)
if it failed, rollback and notify user
issue a "COMMIT"
> DECLARE #LAST_INSERT_ID INT
> DECLARE #EXECUTION_OK char(1)
> SET #EXECUTION_OK = 1
>
> insert into base_table(imgPath,store,apparelType) values (imgPath,store,apparelType)
>
> SELECT #LAST_INSERT_ID = SCOPE_IDENTITY()
>
> insert into data_table(cvID,color) values (#LAST_INSERT_ID, color)
> GO
>
> If exists( Select cvID from data_table where cvID= #LAST_INSERT_ID)
> Begin
> #EXECUTION_OK = 0
> End
I am trying to understand why this trigger keeps giving me an error about invalid use of grouped function when i try to run a basin insert statement to test this out.
I have tried working with this to figure out what i am doing wrong but the error just remains the same. Error 1111
DROP TRIGGER a_num;
DELIMITER //
CREATE TRIGGER a_num BEFORE INSERT ON test_a
FOR EACH ROW BEGIN
DECLARE last INT DEFAULT 0;
INSERT INTO test_b SET full_name = CONCAT_WS(' ', NEW.f_name, NEW.l_name);
SET last = COUNT(id);
UPDATE test_b SET number = CONCAT_WS('-', last, LEFT(NEW.f_name, 2), LEFT(NEW.f_name, 2)) WHERE id = last;
END;
//
Please don't mind the use or poor construction I quite a newb.
Thanks.
I think it should be -
DROP TRIGGER a_num;
DELIMITER //
CREATE TRIGGER a_num BEFORE INSERT ON test_a
FOR EACH ROW BEGIN
DECLARE last INT DEFAULT 0;
INSERT INTO test_b SET full_name = CONCAT_WS(' ', NEW.f_name, NEW.l_name);
SET last = LAST_INSERT_ID();
UPDATE test_b SET number = CONCAT_WS('-', last, LEFT(NEW.f_name, 2), LEFT(NEW.f_name, 2)) WHERE id = last;
END;
//
Can you provide the CREATE statement for test_a and the INSERT statement you're using?
In MySQL Workbench if you right click on test_a go to Copy to Clipboard..Create Statement, will send the table definition.
Is there a reason you're inserting and then updating the same record? Could you combine this into one insert?
I call a procedure, it runs, and the console says "0 rows affected". Is this normal behavior for a MySQL procedure ?
The procedures are clearly doing what they should. One procedure has 2 insert statements, another has an insert and update statement, and I've seen the results with my own eyes. There are indeed rows being affected.
I'm not sure that I would use that result later on, but it seems like I'd want to get an accurate response from my DB whether or not anything was updated, especially when its expected.
Thoughts ?
MySQL 5.5 if it matters, and the procedures use transactions over auto-committed statements.
CREATE DEFINER=`root`#`localhost` PROCEDURE `create_issue`(user_id SMALLINT, title varchar(255), body LONGTEXT)
BEGIN
DECLARE MYUSERID SMALLINT;
DECLARE EXIT HANDLER FOR SQLEXCEPTION BEGIN END;
START TRANSACTION;
INSERT INTO tracker.issue (user_id, title, body, creation_date, last_mod_date) values (user_id, title, body, CURDATE(), CURDATE());
UPDATE user_activity SET last_new_issue = CURDATE(), post_count = post_count + 1 WHERE user_activity.user_id = user_id;
COMMIT;
END
Edited to show the actual query. Also I've been searching and as best as I can tell this is a known issue over a year and a half old. So I suppose this one can be closed.
the "0 rows affected" response is for the last statement executed in the stored procedure.
usually i track the number of rows effected by manually counting them into session variables
DELIMITER $$
CREATE PROCEDURE `create_issue`(user_id SMALLINT, title varchar(255), body LONGTEXT)
BEGIN
DECLARE MYUSERID SMALLINT;
DECLARE EXIT HANDLER FOR SQLEXCEPTION BEGIN END;
SET #inserted_rows = 0;
SET #updated_rows = 0;
START TRANSACTION;
INSERT INTO tracker.issue (user_id, title, body, creation_date, last_mod_date) values (user_id, title, body, CURDATE(), CURDATE());
SET #inserted_rows = ROW_COUNT() + #inserted_rows;
UPDATE user_activity SET last_new_issue = CURDATE(), post_count = post_count + 1 WHERE user_activity.user_id = user_id;
SET #updated_rows = ROW_COUNT() + #updated_rows;
COMMIT;
END
$$
the session variables can then be read after the SP was executed.
i am not sure if it is possible to override the response from the ROW_COUNT() function by setting a value to a variable,
I guess this is a reported bug. May be a good question for MySQL mailing list/forum. http://bugs.mysql.com/bug.php?id=44854
Something definitely isn't right. A sproc should still return the number of rows affected if there are multiple inserts occurring. I'm using the same version of MySQL and this works fine for me.
Are you sure you're not doing something like that
...SET col1='value1' AND col2='value2'...
instead of
...SET COL1='value1', col2='value2'...
Could you post your stored procedure?