I am trying to write a procedure that makes an update to the table by adding a column that is foreign key, but returns error. What could be wrong?
DROP PROCEDURE IF EXISTS tbl_file_add_column_instance_id;
DELIMITER //
CREATE PROCEDURE tbl_file_add_column_instance_id()
BEGIN
IF NOT EXISTS((SELECT column_name FROM information_schema.columns
WHERE table_name = 'tbl_file' AND table_schema = 'diginet2' AND column_name = 'instance_id'))
THEN
ALTER TABLE tbl_file ADD COLUMN instance_id INT NOT NULL AFTER id;
ALTER TABLE tbl_file ADD CONSTRAINT id_instance_arq FOREIGN KEY (`instance_id`) REFERENCES `diginet2`.`tbl_instance` (`id`)
ON DELETE NO ACTION ON UPDATE NO ACTION;
-- Set rows that already exist
SET #query_initial_instance := (SELECT #initial_instance:=id FROM diginet.tbl_instance WHERE instance_status = 1 LIMIT 1);
IF COUNT(#query_initial_instance) = 1
THEN
UPDATE tbl_file SET instance_id = #initial_instance;
ELSE
-- fake throw error
SELECT * FROM diginet_has_none_or_more_than_one_instance;
END IF;
END IF;
END //
DELIMITER ;
CALL tbl_file_add_column_instance_id();
and I am getting this error: Error Code 1111. Invalid use of group function
If you want to know how many rows match the WHERE condition, you should use COUNT() in the query, not the IF statement.
SET #row_count = (SELECT COUNT(*) FROM diginet.tbl_instance WHERE instance_status = 1)
IF #row_count = 1
THEN
UPDATE tbl_file SET instance_id = (SELECT id FROM digitnet.tbl_instance WHERE intance_status = 1);
ELSE
-- fake throw error
SELECT * FROM diginet_has_none_or_more_than_one_instance;
END IF
I don't think there's a legal way to get the count and the sole value in a single query. You could do:
SELECT #row_count := COUNT(*), #initial_instance:=id FROM diginet.tbl_instance WHERE instance_status = 1;
But this violates the ONLY_FULL_GROUP_BY rule.
Related
I am running a MySQL Query. But when a new row is added from form input I get this error:
Error: Can't update table 'brandnames' in stored function/trigger because it is
already used by statement which invoked this stored function/trigger.
From the code:
CREATE TRIGGER `capital` AFTER INSERT ON `brandnames`
FOR EACH
ROW UPDATE brandnames
SET bname = CONCAT( UCASE( LEFT( bname, 1 ) ) , LCASE( SUBSTRING( bname, 2 ) ) )
What does this error mean?
You cannot change a table while the INSERT trigger is firing. The INSERT might do some locking which could result in a deadlock. Also, updating the table from a trigger would then cause the same trigger to fire again in an infinite recursive loop. Both of these reasons are why MySQL prevents you from doing this.
However, depending on what you're trying to achieve, you can access the new values by using NEW.fieldname or even the old values --if doing an UPDATE-- with OLD.
If you had a row named full_brand_name and you wanted to use the first two letters as a short name in the field small_name you could use:
CREATE TRIGGER `capital` BEFORE INSERT ON `brandnames`
FOR EACH ROW BEGIN
SET NEW.short_name = CONCAT(UCASE(LEFT(NEW.full_name,1)) , LCASE(SUBSTRING(NEW.full_name,2)))
END
The correct syntax is:
FOR EACH ROW SET NEW.bname = CONCAT( UCASE( LEFT( NEW.bname, 1 ) )
, LCASE( SUBSTRING( NEW.bname, 2 ) ) )
A "BEFORE-INSERT"-trigger is the only way to realize same-table updates on an insert, and is only possible from MySQL 5.5+. However, the value of an auto-increment field is only available to an "AFTER-INSERT" trigger - it defaults to 0 in the BEFORE-case. Therefore the following example code which would set a previously-calculated surrogate key value based on the auto-increment value id will compile, but not actually work since NEW.id will always be 0:
create table products(id int not null auto_increment, surrogatekey varchar(10), description text);
create trigger trgProductSurrogatekey before insert on product
for each row set NEW.surrogatekey =
(select surrogatekey from surrogatekeys where id = NEW.id);
#gerrit_hoekstra wrote: "However, the value of an auto-increment field is only available to an "AFTER-INSERT" trigger - it defaults to 0 in the BEFORE-case."
That is correct but you can select the auto-increment field value that will be inserted by the subsequent INSERT quite easily. This is an example that works:
CREATE DEFINER = CURRENT_USER TRIGGER `lgffin`.`variable_BEFORE_INSERT` BEFORE INSERT
ON `variable` FOR EACH ROW
BEGIN
SET NEW.prefixed_id = CONCAT(NEW.fixed_variable, (SELECT `AUTO_INCREMENT`
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'lgffin'
AND TABLE_NAME = 'variable'));
END
I have the same problem and fix by add "new." before the field is updated. And I post full trigger here for someone to want to write a trigger
DELIMITER $$
USE `nc`$$
CREATE
TRIGGER `nhachung_province_count_update` BEFORE UPDATE ON `nhachung`
FOR EACH ROW BEGIN
DECLARE slug_province VARCHAR(128);
DECLARE slug_district VARCHAR(128);
IF old.status!=new.status THEN /* neu doi status */
IF new.status="Y" THEN
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
ELSE
UPDATE province SET `count`=`count`-1 WHERE id = new.district_id;
END IF;
ELSEIF old.province_id!=new.province_id THEN /* neu doi province_id + district_id */
UPDATE province SET `count`=`count`+1 WHERE id = new.province_id; /* province_id */
UPDATE province SET `count`=`count`-1 WHERE id = old.province_id;
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id; /* district_id */
UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;
SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);
ELSEIF old.district_id!=new.district_id THEN
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;
SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);
END IF;
END;
$$
DELIMITER ;
Hope this help someone
I am stuck in plsql , as I have making function in which I have to update a table if only values comes in select into ..
and if not come then not and if multiple comes then have to update and delete for all that values .
In below function if in first select into null value comes then should not goto exception handling should update only CUSTOMER table and only delete from table 3 ,, if one or many values comes then do all update and delete for each value
create or replace FUNCTION FUNCTION_NAME (
from_PARTICIPANT_KEY1 IN NUMBER
)
RETURN
IS
to_participant_key1 NUMBER (11);
BEGIN
SELECT to_participant_key
INTO to_participant_key1
FROM TABLE2
WHERE FROM_PARTICIPANT_KEY = from_PARTICIPANT_KEY1;
UPDATE CUSTOMERS C
SET C.CUSTOMER_STATUS_CD =
NVL (
(SELECT old_status_cd
FROM TABLE1
WHERE PARTICIPANT_UID = from_PARTICIPANT_KEY1
AND participant_cd = 'CUSTOMER'),
C.CUSTOMER_STATUS_CD
)
WHERE C.CUSTOMER_UID = from_PARTICIPANT_KEY1;
UPDATE subscribers C
SET C.STATUS_CD =
NVL (
(SELECT old_status_cd
FROM TABLE1
WHERE PARTICIPANT_UID = to_participant_key1
AND participant_cd = 'SUBSCRIBER'),
C.STATUS_CD
)
WHERE C.account_no = to_participant_key1;
DBMS_OUTPUT.PUT_LINE ('Delete TABLE1 rows');
DELETE FROM TABLE3
WHERE PARTICIPANT_UID = from_PARTICIPANT_KEY1 AND participant_cd = 'CUSTOMER';
DELETE FROM TABLE1
WHERE PARTICIPANT_UID = to_PARTICIPANT_KEY1 AND participant_cd = 'SUBSCRIBER';
COMMIT;
EXCEPTION -- exception handlers begin
WHEN NO_DATA_FOUND THEN -- handles 'division by zero' error
dbms_output.put_line('Customer not found ' || from_PARTICIPANT_KEY1);
WHEN OTHERS THEN -- handles all other errors
dbms_output.put_line('Some other kind of error occurred.');
END;
You can use BULK COLLECT INTO and iterate over collection.
First of all, you have to declare (or use some existing) collection type and create the variable of this type:
TYPE participant_keys is table of number (11);
l_participant_keys participant_keys;
Then, your query will change to:
SELECT to_participant_key
BULK COLLECT INTO to_participant_key1
FROM TABLE2
WHERE FROM_PARTICIPANT_KEY = from_PARTICIPANT_KEY1;
If the query will not return any record then you can check it with COUNT:
if l_participant_keys.COUNT = 0 then
-- update only CUSTOMER table and only delete from table 3
else
FOR I IN l_participant_keys.FIRST .. l_participant_keys.LAST LOOP
--use l_participant_keys(i) do all update and delete for each value
END LOOP;
end if;
I need to write a Stored procedure to insert data in a column( unique constraint) in mysql and first i have to check if column is null then i have to check for duplicate, if not then insert the random generated data.
BEGIN
DECLARE key1 VARCHAR(10);
DECLARE accid varchar(32);
WHILE ( select count(*) from account where customerkey is null)>0 DO
SET key1 = (SELECT LEFT(MD5(UUID()), 7));
WHILE (SELECT count(*) FROM account WHERE customerkey = key1) < 1 DO
SET accid = (select id from account where customerkey is null limit 1);
update account set customerkey = key1 where id = accid;
END WHILE;
END WHILE;
END
One doesn't need a loop or separate variables in the procedure. Based on what you've posted, you should be able to get away with a single update statement:
update account set customerkey = LEFT(MD5(UUID()), 7) where customerkey is null;
Try that and let me know if it does the trick.
As an aside reassurance, yes, UUID() returns unique for each row.
SELECT IF((
SELECT COUNT(TABLE_NAME)
FROM information_schema.tables
WHERE TABLE_SCHEMA='database0' AND TABLE_NAME='table'
) >0 , (
SELECT id
FROM database1.table
WHERE id NOT IN (SELECT id FROM database0.table)
), NULL) AS pk_value;
The table database0.table may not exist; if the table does not exist, I want to skip the true clause of the IF statement. Even when the IF statement should return NULL, I get the error that database0.table does not exist. What can I do so that the query returns NULL instead of throwing an error if the table does not exist?
As mentioned in comments, queries are error-checked before they are run, so referring to a non-existent table won't work. You can store it as a function, which is only evaluated at run-time:
DROP FUNCTION IF EXISTS get_pk;
DELIMITER //
CREATE FUNCTION get_pk()
RETURNS INT
BEGIN
DECLARE counter INT;
DECLARE pk_value INT;
SELECT COUNT(table_name) INTO counter
FROM information_schema.tables
WHERE table_schema = 'database0' AND table_name = 'table';
IF counter = 1 THEN
SELECT id INTO pk_value
FROM database1.table
WHERE id NOT IN (SELECT id FROM database0.table);
ELSE
SELECT NULL INTO pk_value;
END IF;
RETURN pk_value;
END//
DELIMITER ;
Then access the value like this:
SELECT get_pk();
I have [ReconcileUserInformationComputed] trigger on Userinformation table
Userinformation table has below rows
[ID] ,[CompanyID] ,[Status] ,[FirstName] ,[LastName]
UserinformationComputed table has below rows
[id] ,[CompanyID] ,[law_id] ,[Status] ,[FirstName] ,[LastName]
Below is my trigger
USE [einvoice]
GO
/****** Object: Trigger [dbo].[ReconcileUserInformationComputed] Script Date: 08/27/2014 10:53:08 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER TRIGGER [dbo].[ReconcileUserInformationComputed] ON [dbo].[UserInformation] AFTER INSERT,DELETE,UPDATE
AS
IF ##ROWCOUNT = 0 -- exit trigger when zero records affected
BEGIN
RETURN
END
SET NOCOUNT ON;
IF EXISTS (SELECT * FROM INSERTED)
BEGIN
IF EXISTS (SELECT * FROM DELETED)
BEGIN
--UPDATE
UPDATE [dbo].[UserInformationComputed]
SET -- use new values from inserted
CompanyID = (SELECT CompanyID from inserted),
law_id = (SELECT ID FROM inserted),
Status = (SELECT Status FROM inserted),
FirstName = (SELECT FirstName FROM inserted),
LastName = (SELECT LastName FROM inserted),
WHERE -- use original values from deleted
law_id = (SELECT ID FROM deleted)
END
ELSE
BEGIN
--INSERT
INSERT INTO [dbo].[UserInformationComputed] (CompanyID,law_id,Status,FirstName,LastName)
SELECT CompanyID,id,Status,FirstName,LastName) FROM inserted
END
END
ELSE IF EXISTS(SELECT * FROM DELETED)
BEGIN
--DELETE
DELETE FROM [dbo].[UserInformationComputed]
WHERE law_id = (SELECT id FROM deleted)
END
when try to update multiple users on Userinformation am getting
below error
Msg 512, Level 16, State 1, Procedure ReconcileUserInformationComputed, Line 16
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.
I made the changes as per the answer it worked for the above trigger but same changes didnt work for another trigger
ALTER TRIGGER [dbo].[ReconcileCrossRefComputed] ON [dbo].[CrossRef] AFTER INSERT, UPDATE, DELETE
AS
IF ##ROWCOUNT = 0 -- exit trigger when zero records affected
BEGIN
RETURN
END
SET NOCOUNT ON;
IF EXISTS (SELECT * FROM INSERTED)
BEGIN
IF EXISTS (SELECT * FROM DELETED)
BEGIN
--UPDATE
UPDATE [dbo].[CrossRefComputed]
SET -- use new values from inserted
SenderId = inserted.SenderId,
ReceiverId = inserted.ReceiverId,
ForeignRef = inserted.ForeignRef,
PolicyID = inserted.PolicyID,
From inserted
WHERE -- use original values from deleted
[CrossRefComputed].SenderId = inserted.SenderId
AND [CrossRefComputed].ReceiverId = inserted.ReceiverId
END
ELSE
BEGIN
--INSERT
INSERT INTO [dbo].[CrossRefComputed] (SenderId, ReceiverId, ForeignRef, PolicyID)
SELECT SenderId, ReceiverId, Effective, PolicyID FROM inserted
END
END
ELSE IF EXISTS(SELECT * FROM DELETED)
BEGIN
--DELETE
DELETE FROM [dbo].[CrossRefComputed]
WHERE SenderId in (SELECT SenderId FROM deleted)
AND ReceiverId in (SELECT ReceiverId FROM deleted)
END
COuld anyone please help me how to fix the procedure to handle updating multiple records?
Be aware that an UPDATE or a DELETE can affect more than one record and your trigger will have to deal with them at once, in this case your "inserted" or "deleted" table will have more than one record.
You will have to use a join in your DML. Something like this:
UPDATE [dbo].[UserInformationComputed]
SET
CompanyID = inserted.CompanyID,
law_id = inserted.ID,
Status = inserted.Status,
FirstName = inserted.FirstName,
LastName = inserted.LastName
from inserted
WHERE
UserInformationComputed.law_id = inserted.ID
I haven't perfectly understood your UPDATE logic, so you'll have to adapt my code.
In your DELETE command you may have just to change "=" to "in":
DELETE FROM [dbo].[UserInformationComputed]
WHERE law_id in (SELECT id FROM deleted)
Take a look at this:
http://msdn.microsoft.com/en-us/library/ms190752.aspx