I want to create an Insert trigger that updates values on all the inserted rows if they're null, the new values should be taken from a different table, according to another column in the inserted table.
I tried:
UPDATE INSERTED
SET TheColumnToBeUpdated =
(
SELECT TheValueCol FROM AnotherTable.ValueCol
WHERE AnotherTable.ValudCol1 = INSERTED.ValueCol1
)
WHERE ValueCol IS NULL
But I get this error:
Msg 286, Level 16, State 1, Procedure ThisTable_INSERT, Line 15
The logical tables INSERTED and DELETED cannot be updated.
How should I do that?
You need to update the destination table, not the logical table. You join with the logical table, though, to figure out which rows to update:
UPDATE YourTable
SET TheColumnToBeUpdated =
(
SELECT TheValueCol FROM AnotherTable.ValueCol
WHERE AnotherTable.ValudCol1 = INSERTED.ValueCol1
)
FROM YourTable Y
JOIN Inserted I ON Y.Key = I.Key
WHERE I.ValueCol IS NULL
You could change the trigger to an INSTEAD OF INSERT. This will let you check the incoming values and, if needed replace them with the values from your other table.
CREATE TRIGGER CoolTrigger
ON MyAwesomeTable
INSTEAD OF INSERT
AS
BEGIN
INSERT MyAwesomeTable (TheValueCol)
SELECT ISNULL(INSERTED.TheValueCol, AnotherTable.TheValueCol) AS TheValueCol
FROM INSERTED
JOIN AnotherTable ON INSERTED.ValueCol1 = AnotherTable.ValueCol1
END
NOTE: INSTEAD OF triggers do NOT cause recursion.
insert into output
(SELECT t1.ts - INTERVAL (SECOND(t1.ts)%10) SECOND,
t1.ts - INTERVAL (SECOND(t1.ts)%10) SECOND + INTERVAL 10 SECOND ,sum(t1.data),
FROM (select * from input
where unix_timestamp(ts) >= unix_timestamp('2000-01-01 00:00:10')
and unix_timestamp(ts) < unix_timestamp('2000-01-01 00:01:20')
)
as t1
GROUP BY UNIX_TIMESTAMP(t1.ts) DIV 10 );
This is where my output table is coming from.
So the insertion is not by values.
Im so sorry but I can't access my account from here (office),
Related
i made a trigger which should avoid inserting a record in the rental 'uitlening' table if the person has an overdue payment (Boete). Unfortunately it doesnt work and i cant find the reason why. 'Boete' is an attribute of another table than rental. Can someone help me?
CREATE TRIGGER [dbo].[Trigger_uitlening]
ON [dbo].[Uitlening]
FOR INSERT
AS
BEGIN
DECLARE #Boete decimal(10, 2);
SET #Boete = (SELECT Boete FROM Lid WHERE LidNr = (SELECT LidNr FROM inserted));
IF #Boete = 0
BEGIN
INSERT INTO Uitlening
SELECT *
FROM inserted;
END;
END;
It sounds like what you actually need is a cross-table constraint.
You can either do this by throwing an error in the trigger:
CREATE TRIGGER [dbo].[Trigger_uitlening]
ON [Rental]
AFTER INSERT
AS
SET NOCOUNT ON;
IF EXISTS (SELECT 1
FROM inserted i
INNER JOIN dbo.Person p ON i.[personID] = p.[personID]
WHERE p.[PaymentDue] <= 0
)
THROW 50001, 'PaymentDue is less than 0', 1;
A better solution is to utilize a trick with an indexed view. This is based on an article by spaghettidba.
We first create a dummy table of two rows
CREATE TABLE dbo.DummyTwoRows (dummy bit not null);
INSERT DummyTwoRows (dummy) VALUES(0),(1);
Then we create the following view:
CREATE VIEW dbo.vwPaymentLessThanZero
WITH SCHEMBINDING -- needs schema-binding
AS
SELECT 1 AS DummyOne
FROM dbo.Rental r
JOIN dbo.Person p ON p.personID = r.personID
CROSS JOIN dbo.DummyTwoRows dtr
WHERE p.PaymentDue <= 0;
This view should in theory always have no rows in it. To enforce that, we create an index on it:
CREATE UNIQUE CLUSTERED INDEX CX_vwPaymentLessThanZero
ON dbo.vwPaymentLessThanZero (DummyOne);
Now if you try to add a row that qualifies for the view, it will fail with a unique violation, because the cross-join is doubling up the rows.
Note that in practice the view index takes up no space because there are never any rows in it.
Assuming you just want to insert records into [Rental] of those users, who have [PaymentDue] <= 0. As you mentioned in your last comment:
no record in rental can be inserted if the person has a PaymentDue
thats greater than zero
And other records should be silently discarded as you didn't give a clear answer to #Larnu's question:
should that row be silently discarded, or should an error be thrown?
If above assumptions are true, your trigger would look like:
CREATE TRIGGER [dbo].[Trigger_uitlening]
ON [Rental]
INSTEAD OF INSERT
AS
BEGIN
INSERT INTO [Rental] ( [DATE], [personID], [productID])
SELECT i.[DATE], i.[personID], i.[productID]
FROM INSERTED i
INNER JOIN Person p ON i.[personID] = p.[personID]
WHERE p.[PaymentDue] <= 0
END;
Attention! When you create a trigger by FOR INSERT or AFTER INSERT then don't write insert into table select * from inserted, because DB will insert data automatically, you can do only ROLLBACK this process. But, when creating a trigger by INSTEAD OF INSERT then you must write insert into table select * from inserted, else inserting not be doing.
I have the following query use for check duplicate data in table. If match data then update row else insert new row. In my case I have already one matched row in att_log table where emp_id=19.1.0121 and where mp_pk_id='32' AND att_date='2021-10-01', so result should be SET holiday=H in the matched row. But the DECLARE statement run without error and in console show affected row:1, but no change occur in data base, holiday not set to "H".
DECLARE c_emp_id att_log.emp_id%type;
BEGIN
SELECT emp_id
INTO c_emp_id
FROM att_log
WHERE emp_id='19.1.0121'
AND emp_pk_id='32'
AND att_date='2021-10-01' ;
EXCEPTION
WHEN TOO_MANY_ROWS THEN
UPDATE att_log
SET holiday = 'H',
updated_at = '2021-08-22'
WHERE emp_id='19.1.0121'
AND att_date='2021-10-01';
WHEN NO_DATA_FOUND THEN
INSERT INTO att_log (emp_id, emp_pk_id, att_date, holiday,login_time, logout_time)
VALUES ('19.1.0121', '32', '2021-10-01','H','','');
COMMIT WORK;
END;
If I run the query separately without DECLARE statement then data row change happen, but with the above DECLARE statement no change happen in data row in the ORACLE table. What is my fault! Sorry, I am new to ORACLE, and also sorry for poor English.
A MERGE operation can INSERT or UPDATE (and also DELETE) depending on whether the row exists or not.
Here's a working test case:
Test case / fiddle
Example of MERGE:
CREATE TABLE logs (
id NUMBER GENERATED BY DEFAULT AS IDENTITY (START WITH 1) NOT NULL
, text VARCHAR2(20) UNIQUE
, q int DEFAULT 1
);
INSERT INTO logs (text) VALUES ('A');
INSERT INTO logs (text) VALUES ('B');
INSERT INTO logs (text) VALUES ('C');
MERGE INTO logs USING (SELECT 'B' AS text FROM dual) cte ON (cte.text = logs.text)
WHEN MATCHED THEN UPDATE SET logs.q = logs.q + 1
WHEN NOT MATCHED THEN INSERT (logs.text)
VALUES (cte.text)
;
Result:
and now we can do this for several existing rows and new rows at once:
MERGE INTO logs USING (
SELECT text FROM logs WHERE text > 'A' UNION
SELECT 'Z' FROM dual
) cte ON (cte.text = logs.text)
WHEN MATCHED THEN UPDATE SET logs.q = logs.q + 1
WHEN NOT MATCHED THEN INSERT (logs.text)
VALUES (cte.text)
;
New Result:
This example will either INSERT a new row when the rows in cte do not exist in logs, and UPDATE any existing rows in logs when matches are found, by incrementing q.
I am attempting to create a T-SQL trigger that will essentially insert x number of rows into a third table based upon the data being inserted into the original table and data contained in a second table; however, I'm getting all sorts of errors in the select portions of the insert statement.
If I comment out this portion [qmgmt].[dbo].[skillColumns].[columnID] in (select columnID from [qmgmt].[dbo].[skillColumns]), IntelliSense gets rid of all the red lines.
Table designs:
Users table - contains user info
skillColumns table - list of all columns possible, filtered on the productGroupID of the user
Skills table - contains the data per user, one row for every columnID in skillColumns
CREATE TRIGGER tr_Users_INSERT
ON [qmgmt].[dbo].[Users]
AFTER INSERT
AS
BEGIN
INSERT into [qmgmt].[dbo].[Skills]([userID], [displayName], [columnID])
Select [iTable].[userID],
[iTable].[displayName],
[cID] in (select [columnID] as [cID] from [qmgmt].[dbo].[skillColumns])
From inserted as [iTable] inner join
[qmgmt].[dbo].[skillColumns] on
[iTable].[productGroupID] = [qmgmt].[dbo].[skillColumns].[groupID]
END
GO
Is what I'm looking to accomplish even possible with a trigger? Can multiple rows be inserted into a table with the in keyword?
UPDATE:
After using the answer provided by J0e3gan, I was able to create a trigger in the opposite direction:
CREATE TRIGGER tr_skillColumns_INSERT_Users
ON [qmgmt].[dbo].[skillColumns]
AFTER INSERT
AS
BEGIN
INTO [qmgmt].[dbo].[Skills]([userID], [displayName], [columnID])
Select [qmgmt].[dbo].[Users].[userID],
[qmgmt].[dbo].[Users].[displayName],
[iTable].[columnID]
From inserted as [iTable] inner Join
[qmgmt].[dbo].[Users] on
[iTable].[groupID] = [qmgmt].[dbo].[Users].[productGroupID]
Where
[qmgmt].[dbo].[Users].[userID] in (select [userID] from [qmgmt].[dbo].[Users])
END
GO
Yes, this can be done with an AFTER trigger.
The column list is not the correct place for the IN criterion that you are trying to use, which is why it is underlined in red.
Try adding the IN criterion to the JOIN criteria instead:
CREATE TRIGGER tr_Users_INSERT
ON [qmgmt].[dbo].[Users]
AFTER INSERT
AS
BEGIN
INSERT into [qmgmt].[dbo].[Skills]([userID], [displayName], [columnID])
Select [iTable].[userID],
[iTable].[displayName],
[qmgmt].[dbo].[skillColumns].[columnID]
From inserted as [iTable] inner join
[qmgmt].[dbo].[skillColumns] on
[iTable].[productGroupID] = [qmgmt].[dbo].[skillColumns].[groupID] and
[qmgmt].[dbo].[skillColumns].[columnID] in (select columnID from [qmgmt].[dbo].[skillColumns])
END
GO
Alternatively add it to a WHERE clause:
CREATE TRIGGER tr_Users_INSERT
ON [qmgmt].[dbo].[Users]
AFTER INSERT
AS
BEGIN
INSERT into [qmgmt].[dbo].[Skills]([userID], [displayName], [columnID])
Select [iTable].[userID],
[iTable].[displayName],
[qmgmt].[dbo].[skillColumns].[columnID]
From inserted as [iTable] inner join
[qmgmt].[dbo].[skillColumns] on
[iTable].[productGroupID] = [qmgmt].[dbo].[skillColumns].[groupID]
Where
[qmgmt].[dbo].[skillColumns].[columnID] in (select columnID from [qmgmt].[dbo].[skillColumns])
END
GO
For example, I want to know at any moment most popular records that users searched in the database.
I expect that for each record I need to introduce a new number field. Thus, the record will be like this:
key - value - counter
How I can to increase the value of counter inside a database?
I think it's something like calling a stored procedure while a query, but I'm not sure. Perhaps the question is quite simple, I'm just a beginner and I apologize in that case.
You should use a trigger for this. Triggers are commands that execute on events, everytime an INSERT, UPDATE or DELETE statement is executed, even if their calls do not modify any records. Due tot this, you can't directly create a trigger for updating the count field of a record when you SELECT (read) it.
But, you can try a workaround in which you also have a date field in your table, and update it everytime a record is called. Use your application to send this datetime value to the database, which will trigger an UPDATE.
By making an UPDATE statement, your trigger is called and this way you can add your code to modify the count column.
CREATE TRIGGER tafter AFTER INSERT OR DELETE ON tbl1 FOR EACH ROW UPDATE SET counter = counter + 1 where key = 'keyval';
Firstly, this sounds like an awful performance problem. Every time you select a record you have to update it if you're tracking the selects with a single number, which just stores total selects, otherwise you have to insert timestamped values into another table to be able to analyse when the rows were read.
Anyway, you can do this with a common table expression in which you update a counter in the table and return the results to the main query: http://sqlfiddle.com/#!1/1aa41/6
Code something like:
create table my_table(col1 varchar(30), col2 numeric, select_count numeric);
insert into my_table values ('A',1,0);
insert into my_table values ('B',2,0);
insert into my_table values ('C',3,0);
insert into my_table values ('D',4,0);
insert into my_table values ('E',5,0);
with upd as (
update my_table
set select_count = select_count+1
where col1 = 'A'
returning *)
select *
from upd;
with upd as (
update my_table
set select_count = select_count+1
where col1 = 'B'
returning *)
select *
from upd;
with upd as (
update my_table
set select_count = select_count+1
where col1 = 'A'
returning *)
select *
from upd;
with upd as (
update my_table
set select_count = select_count+1
returning *)
select count(*)
from upd;
with upd as (
update my_table
set select_count = select_count+1
returning *)
select sum(col2)
from upd;
with upd as (
update my_table
set select_count = select_count+1
returning *)
select *
from upd;
Here's what I'm trying to do:
1) Insert into a temp table some values from an original table
INSERT INTO temp_table SELECT id FROM original WHERE status='t'
2) Update the original table
UPDATE original SET valid='t' WHERE status='t'
3) Select based on a join between the two tables
SELECT * FROM original WHERE temp_table.id = original.id
Is there a way to combine steps 1 and 2?
You can combine the steps by doing the update in PL/SQL and using the RETURNING clause to get the updated ids into a PL/SQL table.
EDIT:
If you still need to do the final query, you can still use this method to insert into the temp_table; although depending on what that last query is for, there may be other ways of achieving what you want. To illustrate:
DECLARE
id_table_t IS TABLE OF original.id%TYPE INDEX BY PLS_INTEGER;
id_table id_table_t;
BEGIN
UPDATE original SET valid='t' WHERE status='t'
RETURNING id INTO id_table;
FORALL i IN 1..id_table.COUNT
INSERT INTO temp_table
VALUES (id_table(i));
END;
/
SELECT * FROM original WHERE temp_table.id = original.id;
No, DML statements can not be mixed.
There's a MERGE statement, but it's only for operations on a single table.
Maybe create a TRIGGER wich fires after inserting into a temp_table and updates the original
Create a cursor holding the values from insert and then loop through the cursor updating the table. No need to create temp table in the first place.
You can combine steps 1 and 2 using a MERGE statement and DML error logging. Select twice as many rows, update half of them, and force the other half to fail and then be inserted into an error log that you can use as your temporary table.
The solution below assumes that you have a primary key constraint on ID, but there are other ways you could force a failure.
Although I think this is pretty cool, I would recommend you not use it. It looks very weird, has some strange issues (the inserts into TEMP_TABLE are auto-committed), and is probably very slow.
--Create ORIGINAL table for testing.
--Primary key will be intentionally violated later.
create table original (id number, status varchar2(10), valid varchar2(10)
,primary key (id));
--Create TEMP_TABLE as error log. There will be some extra columns generated.
begin
dbms_errlog.create_error_log(dml_table_name => 'ORIGINAL'
,err_log_table_name => 'TEMP_TABLE');
end;
/
--Test data
insert into original values(1, 't', null);
insert into original values(2, 't', null);
insert into original values(3, 's', null);
commit;
--Update rows in ORIGINAL and also insert those updated rows to TEMP_TABLE.
merge into original original1
using
(
--Duplicate the rows. Only choose rows with the relevant status.
select id, status, valid, rownumber
from original
cross join
(select 1 rownumber from dual union all select 2 rownumber from dual)
where status = 't'
) original2
on (original1.id = original2.id and original2.rownumber = 1)
--Only math half the rows, those with rownumber = 1.
when matched then update set valid = 't'
--The other half will be inserted. Inserting ID causes a PK error and will
--insert the data into the error table, TEMP_TABLE.
when not matched then insert(original1.id, original1.status, original1.valid)
values(original2.id, original2.status, original2.valid)
log errors into temp_table reject limit 999999999;
--Expected: ORIGINAL rows 1 and 2 have VALID = 't'.
--TEMP_TABLE has the two original values for ID 1 and 2.
select * from original;
select * from temp_table;