Is there any way to create triggers on two different databases in Mysql? my requirement is like:-
database: test1 -> table: tmp1
database: test2 -> table: tmp2
now I have to use trigger on test1 insert operation happens on tmp1 a value has to be inserted into tmp2 of test2 database. And also vice a verse.
i.e. one more trigger on tmp2 table of test2 database, if insert into tmp2 then inserted into tmp1 table of test1 database.
I have tried to write the trigger on both but I think it will goes into loop to insert each other tables.
DELIMITER $$
CREATE TRIGGER trigger_ad_t1 AFTER insert ON `test1`.tmp1
FOR EACH ROW
Begin
INSERT INTO `test2`.tmp2 VALUES (NEW.employeeNumber,New.fname,New.lname)
END$$
DELIMITER ;
same type of trigger written for insert into tmp1 after insert into tmp2 table.
One more thing I have tested this trigger on my local pc which has mysql 5.1.63 but when I am trying this trigger on my testing server which has mysql 5.0.45 then it gives me syntax error(1064). Don't know what is the problem?
UPDATE:
Can anybody help me to get rid of it.
Thanks
Use fully qualified table names in your trigger.
I.e.
db1.test1.* and d2.test2.*
P.S. After looking at your SQL one more time I realised that you ARE doing the above already.
Edit: Comment field is to restrictive to post code, so here is how you prevent the endless insert loop (assuming employeeNumber is unique key):
Edited code:
IF NOT EXISTS(SELECT employeeNumber FROM otherDB.otherTable WHERE employeeNumber = NEW.employeeNumber) THEN
INSERT INTO otherDB.otherTable VALUES (NEW.employeeNumber,New.fname,New.lname)
END IF;
Correction was needed in the code provided originally:
... EXISTS(SELECT * FROM otherDB.otherTable ...) is replaced with
... EXISTS(SELECT employeeNumber FROM otherDB.otherTable ...)
The reason being that the first query will always return true because the inner query SELECT * FROM ... always returns one record containing the number of results =>
EXISTS(SELECT * FROM ...) is always true
Related
DROP PROCEDURE IF EXISTS kund2orderNew;
DELIMITER ;;
CREATE PROCEDURE kund2orderNew(kundId2 INT)
BEGIN
IF kundId2 <> (SELECT kundId FROM kund2order) THEN
INSERT INTO kundOrder VALUES ();
INSERT INTO kund2order VALUES (kundId2, (SELECT id FROM kundOrder));
END IF;
END
;;
DELIMITER ;
Alright am I doing something wrong here? What im trying to do is to check if kundId is in the kund2order, if its not then what I want to do is create a new row in the kundOrder table that just uses the default values and then take the recently created id from that row in the kundOrder and put it inside the new row in kund2order (together with kundId).
For some reason it just gives me (node:18328) UnhandledPromiseRejectionWarning: Error: ER_BAD_NULL_ERROR: Column 'kundId' cannot be null
I am a bit confused as to what the problem is, both tables are empty after I have called this procedure. Is the problem my if statement or is it something else?
That's not the correct way to check if an ID is already in the table. When you use a SELECT query as an expression, it has to return just one row. You can use:
IF NOT EXISTS (SELECT * FROM kund2Order WHERE kundId = kundId2) THEN
And if you want to insert the auto-increment of the row that was just inserted into kundOrder, you should use LAST_INSERT_ID():
INSERT INTO kund2order VALUES (kundId2, LAST_INSERT_ID());
I'm trying to do some mysql trigger coding. I fail every time I meet loops.
CREATE TRIGGER `after_insert` AFTER INSERT ON `table_users`
FOR EACH ROW BEGIN
INSERT INTO table_user_plan (user_id, plan_id) VALUES
(NEW.id, (SELECT id FROM table_plans))
;
END
Here trigger is successfully created, but I get error
#1242 - Subquery returns more than 1 row
I understand this cannot work, because there are more than one row in table_plans... but how can I handle this if I want to add multiple rows or how can I make a loop and firstly select plans then insert into table_users?
Thanks in advanced
To insert multiple rows based on a SELECT you would use the INSERT ... SELECT FROM ... syntax. In this case, you would use something like
INSERT INTO table_user_plan
SELECT NEW.id AS user_id, tp.id AS plan_id
FROM table_plans tp;
(I think that should work, although I've never actually tried to use NEW in this context.)
I have a table which contain some fields(id,code,name,...), when I want to insert new record the code field should be like (ABC-001) and next record should be like (ABC-002) and so on.
I want to write a MYSQL procedure for this but I don't know how, any body has any idea? thanks in advance
First User Insert Query like:
Insert Into YourTable Values(..,'ABC',...);
Now write trigger after update which set Code value in expected format:
CREATE TRIGGER TriggerNmae AFTER INSERT ON YourTable
FOR EACH ROW
Begin
UPDATE YourTable
SET code = concat(code,'-',LPAD(NEW.id,3,'0'));
WHERE id = New.id ;
END;
I'm having a problem with my sql query. I need to insert a data that needs to be checked first if it is existing or not. If the data is existing the sql query must return it, if not insert and return it. I already google it but the result is not quite suitable to my problem. I already read this.
Check if a row exists, otherwise insert
How to 'insert if not exists' in MySQL?
Here is a query that' I'm thinking.
INSERT INTO #tablename(#field, #conditional_field, #field, #conditional_field)
VALUES(
"value of field"
(SQL QUERY THAT CHECK IF THERE IS AN EXISTING DATA, IF NOT INSERT THE DATA and RETURN IT, IF YES return it),
"value of feild",
(SQL QUERY THAT CHECK IF THERE IS AN EXISTING DATA, IF NOT INSERT THE DATA and RETURN IT, IF YES return it)
);
Please take note that the conditional field is a required field so it can't be NULL.
Your tag set is quite weird, I'm unsure you require all the technologies listed but as long as Firebird is concerned there's UPDATE OR INSERT (link) construction.
The code could be like
UPDATE OR INSERT INTO aTable
VALUES (...)
MATCHING (ID, SomeColumn)
RETURNING ID, SomeColumn
Note that this will only work for PK match, no complex logic available. If that's not an option, you could use EXECUTE BLOCK which has all the power of stored procedures but is executed as usual query. And you'll get into concurrent update error if two clients execute updates at one time.
You could split it out into 2 steps
1. run a select statement to retrieve the rows that match your valus. select count (*) will give you the number of rows
2. If zero rows found, then run the insert to add the new values.
Alternatively, you could create a unique index form all your columns. If you try to insert a row where all the values exist, an error will be returned. You could then run a select statement to get the ID for this existing row. Otherwise, the insert will work.
You can check with if exists(select count(*) from #tablename) to see if there is data, but with insert into you need to insert data for all columns, so if there is only #field missing, you cant insert values with insert into, you will need to update the table and go with a little different method. And im not sure, why do you check every row? You know for every row what is missing? Are you comparing with some other table?
You can achieve it using MySQL stored procedure
Sample MySQL stored procedure
CREATE TABLE MyTable
(`ID` int, `ConditionField` varchar(10))
;
INSERT INTO MyTable
(`ID`, `ConditionField`)
VALUES
(1, 'Condition1'),
(1, 'Condition2')
;
CREATE PROCEDURE simpleproc (IN identifier INT,ConditionData varchar(10))
BEGIN
IF (SELECT ID FROM MyTable WHERE `ConditionField`=ConditionData) THEN
BEGIN
SELECT * FROM MyTable WHERE `ConditionField`=ConditionData;
END;
ELSE
BEGIN
INSERT INTO MyTable VALUES (identifier,ConditionData);
SELECT * FROM MyTable WHERE `ConditionField`=ConditionData;
END;
END IF;
END//
To Call stored procedure
CALL simpleproc(3,'Condition3');
DEMO
I have the following three (InnoDB-) tables in a MySQL database:
Entity (DLID)
Category (CatID, CatName)
hasCategory (DLID, CatID)
Now, upon insertion into the table hasCategory I would like to make sure, that each Entity is associated with at least one Category. Thus, I wrote the following trigger:
delimiter |
create trigger Max before insert on hasCategory for each row begin
if (exists (select distinct DLID from Entity where not exists (select distinct new.DLID from new))) then
signal sqlstate '45000'
set message_text = 'Min of 1 category per entity required';
end if;
end|
delimiter ;
Now, when I execute the following query: insert into hasCategory values (1, 1); I get the error error code 1146: table mydb.new does not exist. I have created some other triggers similar to this one, also referring to the new-table, where it worked perfectly well. Yet, I don't get it, what causes the error in this particular trigger.
Is it possible that the select statement causes some trouble? I've read that only select into statements are valid in procedures, but I don't know if this has got anything to do with this.
Thanks for your help!
select distinct new.DLID from new
there is no table new in your DB just as the error states. You can use NEW for the record that will be inserted in your trigger but you cannot use it as a table name and select from it.
try
if (select 1 from Entity where DLID = new.DLID) = 1 then