CREATE TABLE child_tab
(
col_x INTEGER NOT NULL,
CONSTRAINT fk FOREIGN KEY (col_x) REFERENCES parent_tab(col_a) ON DELETE CASCADE
);
The conversion would remove the foreign key definition and add this trigger:
CREATE TRIGGER tr_single
ON parent_tab INSTEAD OF DELETE
AS BEGIN
DELETE FROM child_tab WHERE (child_tab.col_x IN (SELECT col_a FROM deleted))
DELETE FROM parent_tab WHERE (parent_tab.col_a IN (SELECT col_a FROM deleted))
END;
Unfortunately, now I need to resolve a situation where there is involved a multi-column foreign key.
CREATE TABLE parent_tab
(
col_a INTEGER NOT NULL,
col_b INTEGER NOT NULL,
CONSTRAINT pk PRIMARY KEY(col_a, col_b)
);
CREATE TABLE child_tab
(
col_x INTEGER NOT NULL,
col_y INTEGER NOT NULL,
CONSTRAINT fk FOREIGN KEY (col_x, col_y) REFERENCES parent_tab(col_a, col_b) ON DELETE CASCADE
);
This does not work, because the temporary table "deleted" might contain more than one row. How do I make sure that the values belong to the same row?
-- incorrect trigger, might delete too many rows
CREATE TRIGGER tr_single
ON parent_tab INSTEAD OF DELETE
AS BEGIN
DELETE FROM child_tab WHERE (child_tab.col_x IN (SELECT col_a FROM deleted) AND child_tab.col_y IN (SELECT col_b FROM deleted))
DELETE FROM parent_tab WHERE (parent_tab.col_a IN (SELECT col_a FROM deleted) AND parent_tab.col_b IN (SELECT col_b FROM deleted))
END;
-- some magic needed :-)
CREATE TRIGGER tr_single
ON parent_tab INSTEAD OF DELETE
AS BEGIN
DELETE FROM child_tab WHERE (child_tab.col_x IN (SELECT col_a FROM deleted AS t1) AND child_tab.col_y IN (SELECT col_b FROM deleted AS t2) AND row_id(t1) = row_id(t2))
DELETE FROM parent_tab WHERE (parent_tab.col_a IN (SELECT col_a FROM deleted AS t1) AND parent_tab.col_b IN (SELECT col_b FROM deleted AS t2) AND row_id(t1) = row_id(t2))
END;
I know the trigger definition above is ***... but I hope that it helps to make clear what I need.
I am using SQL server 2000. I have a parent table 'MimeTypes' with primary key 'mimetype'. This is referenced as foreign key in table 'AssetTypes' as column 'BaseMimeType'. The referential constraint is simple : alter table AssetTypes add constraint FK_ASSETTYPES_REF_BASEMIMETYPE foreign key (BaseMimeType) references MimeTypes (MimeType) on update no action on delete no action;
I have FOR Update trigger on parent table ('MimeTypes') which is as follows:
CREATE TRIGGER trg_MimeTypes_update ON MimeTypes FOR UPDATE AS IF UPDATE(MimeType) BEGIN UPDATE AssetTypes SET BaseMimeType = (select MimeType from inserted) FROM AssetTypes as A JOIN deleted as d on A.BaseMimeType = d.MimeType END;
******** The problem is simple. I want to execute a update query on parent table ('MimeTypes') which modifies 'mimetype' value referenced by child. I dont want to include cascade option in constraint. When such query is executed error comes as : UPDATE statement conflicted with COLUMN REFERENCE constraint 'FK_ASSETTYPES_REF_BASEMIMETYPE'. The conflict occurred in database 'default.db', table 'AssetTypes', column 'BaseMimeType'. ***** Is there any way to do this?
Is it possible to define a referential constraint between two tables in two different databases (on two servers)? Or are there beter best practices methods/products to achieve this result.
First of all, I've been a reader of swynk.com for quite sometime now, and I'd like to say 'thank you' to everyone who contributes.
Today, I'm the town moron.. haha I'm having issues with column level constraints. I have a varchar(50) where I want to keep *,=,#,/, .. etc, OUT OF the value input. I don't want to strip them. I simply want for sql to throw an error if the insert contains those (and other characters). The only characters that I want in the column are A-Z and 0-9. However, it's not a set number of characters per insert. It always varies... There has to be an easier way to do this than creating a constraint for every possibilty... Any help would be greatly appreciated.
I'm not sure about the way you enforce the referential integrity in a SQL server 6.5 database (I'm new to this environment). Does any one have an exemple. The doc I have is useless...Thanks
Hi, I need to write a referential integrity trigger. I have two tables called Table1 and Table2. In both the tables i have common column called FieldA. Now i need to write a trigger, whenever i updates Table1 this trigger automatically needs to update a FieldA in Table2. Can anyone give me Code or suggestions , how to write this trigger. I am new to triggers. Thank you!
Hi, I need to write a referential integrity trigger. I have two tables called Table1 and Table2. In both the tables i have common column called FieldA. Now i need to write a trigger, whenever i updates Table1 this trigger automatically needs to update a FieldA in Table2. Can anyone give me Code or suggestions , how to write this trigger. I am new to triggers. Thank you! I know how to write a normal insert , update, delete triggers and using help from books online.. SO pls do it in useful.
I am inserting into a table that hold several foreign keys from several tables. I'm performing this via a client (VB) and I only how to capture the error, but unable to determine which column/field is the one that violates referential integrity.
I am having great difficulty with cascading deletes, delete triggers and referential integrity.
The database is in First Normal Form.
I have some tables that are child tables with two foreign keyes to two different parent tables, for example:
Table A / Table B Table C / Table D
So if I try to turn on cascading deletes for A/B, A/C, B/D and C/D relationships, I get an error that I cannot have cascading delete because it would create multiple cascade paths. I do understand why this is happening. If I delete a row in Table A, I want it to delete child rows in Table B and table C, and then child rows in table D as well. But if I delete a row in Table C, I want it to delete child rows in Table D, and if I delete a row in Table B, I want it to also delete child rows in Table D.
SQL sees this as cyclical, because if I delete a row in table A, both table B and table C would try to delete their child rows in table D.
Ok, so I thought, no biggie, I'll just use delete triggers. So I created delete triggers that will delete child rows in table B and table C when deleting a row in table A. Then I created triggers in both Table B and Table C that would delete child rows in Table D.
When I try to delete a row in table A, B or C, I get the error "Delete Statement Conflicted with COLUMN REFERENCE". This does not make sense to me, can anyone explain? I have a trigger in place that should be deleting the child rows before it attempts to delete the parent row...isn't that the whole point of delete triggers?????
This is an example of my delete trigger:
CREATE TRIGGER [DeleteA] ON A FOR DELETE AS Delete from B where MeetingID = ID; Delete from C where MeetingID = ID;
And then Table B and C both have delete triggers to delete child rows in table D. But it never gets to that point, none of the triggers execute because the above error happens first.
So if I then go into the relationships, and deselect the option for "Enforce relationship for INSERTs and UPDATEs" these triggers all work just fine. Only problem is that now I have no referential integrity and I can simply create unrestrained child rows that do not reference actual foreign keys in the parent table.
So the question is, how do I maintain referential integrity and also have the database delete child rows, keeping in mind that the cascading deletes will not work because of the multiple cascade paths (which are certainly required).
I have a table that allows a user (from another table) to belong to multiple organizations. Part of this table's schema is a column that will be used to allow the user to indicate which organization that they belong to will be the primary one. A user can only have one PRIMARY organization. I was going to handle via an Insert or Update Trigger...checking to see if the userid already a Primary. However, now I am wondering if a Constraint would be the way to go? I admit though, I don't know enough about Constraints to know how this would work.
The table's schema is like: UserOrg UserOrgID (an identity column) UserID (foreign key to the user's table) Org (the name of the org) PrimaryOrg (bit column)
I do not know this is the correct way to do this, but somehow thisisnt working. All I want is not to have a null value in field A ifthere is a value in field Bheres the codeCREATE TRIGGER tiu_name ON tblNameFOR INSERT, UPDATEASDECLARE @FieldA AS REAL, @FieldB AS REAL;SELECT @FieldA=FieldA, @FieldB=FieldBFROM Inserted;IF (@FieldB IS NOT NULL) AND (@FieldA IS NULL)RAISERROR('Error Message',1,2);GOPlease Help.
I am not sure if this is the correct forum but i thought i'd ask and see if you can help me!
I have a table with 2 columns:
1st column will house numbers from 1 to 50
2nd column will be date
I want the users to be able to pick a number for certain date and enter it to the table, however I don't want the system to allow the same number for the same date. I was looking at constraints and triggers but can't make out what exactly i should use and how. The Insert will be initiated from ASP page on our intranet. Please help!!!
The majority of my database experience comes from ORACLE and i am trying to use some functionality that i have already used in Oracle into a project i am working on in MSDE.
I want to create a trigger that uses a DML constraint that will prevent a tenants from being inserted into a house if the bedroom count is less or equal to the number of tenants currently in the house.
The oracle code is below
CREATE OR REPLACE TRIGGER Tenant_room_check BEFORE INSERT or update of tenant_ID ON Tenant FOR each row as (new.tenant_ID is not null) DECLARE Tenant_count NUMBER; Bedroom_count NUMBER; BEGIN
select count(Tenant_ID) as Tenant_count from Tenant where tenant_ID = :new.tenant_ID and House_ID = 1 AND Tenant_status = 1;
select count(ROOM_ID) as bedroom_count from Room where Room_Name = 'Bedroom' and House_ID = 1
if (Tenant_count > Bedroom_count) then raise_application_error(-20601, 'you cannot have more tenants than the number of bedrooms in a student house');
END IF; END; /
Ideally I would like to pass the HOUSE_ID and the TENANT_ID from my application using @variablename
I have been looking over forums and in books but i am getting all confused over the syntax to use.
In my Projecti want to check the date at the time of insert in A-Tablethat it should be Greater than (>) Date Defined in B-TableNote:-B-table have only one record so plz tell me how can i do using Sql-Server Backend only
I want to incorporate a Check constraint within a trigger, based on this but im struggling with the coding.Assuming that is an Alphanumeric field you should be checking what value is in the alphanumeric column from inserted, comparing it with whatever is in the AMGR_User_Fields_Tbl to see if there’s a duplicate and then raising the error...This is my Trigger:
ALTER TRIGGER [dbo].[DUPLICATES] ON [dbo].[AMGR_User_Fields_Tbl]
FOR INSERT, UPDATE AS DECLARE @Alphanumericcol VARCHAR (750)
-- This trigger has been created to check that duplicate rows are not inserted into table.
-- Check if row exists SELECT @Alphanumericcol FROM Inserted i, AMGR_User_Fields_Tbl t
Hi, Can anyone tell me the order in which uniqueness constraints on indexes are enforced vs. when triggers are executed ? I have a unique constraint on an index and a trigger on the column on which the same index has been created. When a row is inserted, the trigger checks if the value for that column already exists in the table - if not, it inserts the row as is, else it gets the max() val of the column (based on another key column) and increments it by one, then does the insert. Creating an index across the two works fine, but if I set the Unique Values property for the index, subsequent inserts bomb out - yet there aren't any duplicates in the final table, as the trigger ensures this. Anyone got any ideas on this? My deduction is that the uniqueness constraint gets enforced before the trigger gets executed, but at the same time this *seems* illogical, as the row has not been inserted into the table at the point where the trigger is executed.
how to i write a trigger to enforce this constraint..A rental can be made only if the customer is registered with the company and the car is not currently rented out. If not, the rental will not be successful.
We have a database where many tables have a field that has to be lengthened. In some cases this is a primary key or part of a primary key. The table in question is:-
/****** Object: Table [dbo].[DTb_HWSQueueMonthEnd] Script Date: 09/25/2014 14:05:09 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[DTb_HWSQueueMonthEnd](
[Code] ....
The script I am using is
DECLARE@Column varchar(100)--The name of the column to change DECLARE@size varchar(5)--The new size of the column DECLARE @TSQL varchar(255)--Contains the code to be executed DECLARE @Object varchar(50)--Holds the name of the table DECLARE @dropc varchar(255)-- Drop constraint script
[Code] ....
When I the the script I get the error message Could not create constraint. See previous errors.
Looking at the strings I build
ALTER TABLE [dbo].[DTb_HWSQueueMonthEnd] DROP CONSTRAINT PK_DTb_HWSQueueMonthEnd ALTER TABLE [dbo].[DTb_HWSQueueMonthEnd] Alter Column [Patient System Number] varchar(10) ALTER TABLE [dbo].[DTb_HWSQueueMonthEnd] ADD CONSTRAINT PK_DTb_HWSQueueMonthEnd PRIMARY KEY NONCLUSTERED ([Patient System Number] ASC,[Episode Number] ASC,[CensusDate] ASC) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
They all seem fine except the last one which returns the error
Msg 8111, Level 16, State 1, Line 1 Cannot define PRIMARY KEY constraint on nullable column in table 'DTb_HWSQueueMonthEnd'. Msg 1750, Level 16, State 0, Line 1 Could not create constraint. See previous errors.
None of the fields I try to create the key on are nullable.
I'm pretty new at T-SQL programming, though I'm pretty familiar with most SQL statements. I'm trying to write an insert trigger that handles a multi-row insert, but I'm avoiding using cursors (which I'll have to resort to if all else fails). I've looked everwhere I can think of for an answer, outside of buying another book, but I can't seem to find a solution. Anyone have a good way I can alter this trigger to accept multirow inserts without using a cursor?Note: The purpose of this trigger is to copy the features of a mobile phone account whenever a new mobile phone account is created (as in this is the information for an invoice, and the mobile account is to be copied and updated for the new invoice each month.)CREATE TRIGGER [copymobilefeatures] ON [dbo].[mobilesub] FOR INSERTAS insert into #featuresselect i.invoicedate, i.subaccountnumber, i.planid, f.featureidfrom mobilesub m join (inserted i join mobilefeatures f on i.invoicedate = f.invoicedate ) on m.subaccountnumber = f.subaccountnumber insert into mobilefeatures(invoicedate, subaccountnumber, planid, featureid)select * from #featuresI'd love code examples, but a detailed written explaination of what needs to be done might be even more helpful. I'm looking for understanding, not just something I can copy and paste. Thanks!
I need to update LastReceivedQty and LastReceivedDate fields in the Product table each time a DeliveryNoteDetail entry is created for a PurchaseOrderDetail line.
DeliveryNote has the ReceivedDate DeliveryNoteDetail has the ReceivedQty
I made the following trigger for handling single row updates, which works fine.
UPDATE Purchasing.Product SET LastReceivedQty = i.ReceivedQty, LastReceivedDate = dn.ReceivedDate FROM Purchasing.DeliveryNote dn INNER JOIN Purchasing.DeliveryNoteDetail dnd ON dn.DeliveryNoteID = dnd.DeliveryNoteID INNER JOIN inserted i ON dnd.DeliveryNoteDetailID = i.DeliveryNoteDetailID INNER JOIN Purchasing.PurchaseOrderDetail pod ON dnd.PurchaseOrderDetailID = pod.PurchaseOrderDetailID INNER JOIN Purchasing.Product p ON pod.VendorVendorProductID = p.VendorVendorProductID
Now I don't know how to handle multi-row situations when the same product is updated. Since I cannot rely on the order that the updates are performed I need to somehow select the MAX(ReceivedDate).
I would like to know how to, if at all possible, to reconstruct the following trigger as to be able to handle multiple row insert when a single insert command is used - because the trigger will only be called once...I'm not familiar and don't know anything about cursors and i've read that its not the best way to go.
TRIGGER ON childtable INSTEAD OF INSERT AS BEGIN DECLARE @customkey char(16); DECLARE @nextchild int; DECLARE @parent int; DECLARE @date datetime;
SET @date = getdate();
SELECT @parent = parenttable FROM inserted;
SELECT @nextchild=count(*)+1 FROM childtable WHERE parenttable = @parent;
I am trying to exclude records from a table where the ID column is the same but the Mail code Column is multi-valued.For Example: (the table looks like....)
I have two tables, one a data table, the other a product table. I want to perform a join on the two tables with values distributed into columns based on the value in the month field.
I have an update trigger on a table. When a specific column is updated, I get the rowid from 'inserted' and then pass it via service broker to another database that will fire off a maintenance routine at a later time. This whole process seems to work fine if I update a single row at a time through Query Analyzer.
During testing (of the service broker part) I found that if in Query Analyzer I run an update that updates all of the records at once, then the trigger seems to fire only once for the entire process, therefore killing the rest of my process.
I would have thought that regardless of how a record was being updated the trigger would fire atomically for each row.
Hi,Would like to know the performance differenece between Multi-columnIndex vs Single Column Indexes. Let's say I have a table with col1,col2, col3 along with a primary key column and non-indexed columns.In queries, I will use col1, col2, and col3 together and some timesjust one or two of these three columns. My questions is, should Icreate one index contains col1, col2, and col3, or create 3 seperatedcolumns. I.e. each column has its own index. Any performancedifference?Thanks a lot.
how to do this i have table of employee ,evry employee have a unique ID "empid" empid VAL_OK -------------------------- 111 0 222 0 333 0
now insert multiple insert to my work_table shifts for all month for evry employee like this (this is work_table) empid date val -------------------------------------------------- 111 01/02/2008 1 111 02/02/2008 2 ............... 111 29/02/2008 5 --next employee 222 01/02/2008 1 222 02/02/2008 4 ............... 222 29/02/2008 6 --next employee 333 --next employee 444 --next employee 555 -------------------------------------------------------------
now i need for evry OK insert (for all month) each employee go to the TB_Employee and update each employee once !! from VAL_OK=0 to VAL_OK=1 like this
empid VAL_OK -------------------------- 111 1 222 1 333 1 ---------------------- like this i know who is the employee have shift for all month and who NOT !
i think it like this
Code Snippet Create trigger for_insert on tb_work For insert begin if @@rowcount = 1 Update tb_employee Set val_ok= 1
else /* when @@rowcount is greater than 1, use a group by clause */ Update tb_employee set val_ok= 1 select empid from tb_work group by tb_work.empid
How can you indicate that a FOREIGN KEY constraint references twocolumns in two different tables?"SQL Server Books Online" show an example of how to reference twocolumns in the SAME table:REFERENCES ref_table [ ( ref_column [ ,...n ] )Here is the error and the 'bad' SQL code:Server: Msg 8148, Level 16, State 1, Line 4More than one column FOREIGN KEY constraint specified for column'UserOrGroupId', table 'salesforce3.dbo.AccountShare'.CREATE TABLE salesforce3.dbo."AccountShare" ("Id" varchar(18) PRIMARYKEY , ... , "UserOrGroupId" varchar(18) CONSTRAINTFK_UserOrGroupId6349 FOREIGN KEY REFERENCES "User"(Id) REFERENCES"Group"(Id) , ... )
I'm a newbie have trouble using the "inserted" table in a trigger. When I run these SQL statements:CREATE DATABASE foobarGOUSE foobar GOCREATE TABLE foo ( fooID int IDENTITY (1, 1) NOT NULL, lastUpdated datetime, lastValue int, PRIMARY KEY(fooID))GOCREATE TABLE bar ( barID int IDENTITY (1, 1) NOT NULL, fooID int NOT NULL, [value] int NOT NULL, updated datetime NOT NULL DEFAULT (getdate()), primary key(barID), foreign key(fooID) references foo (fooID))GOCREATE TRIGGER onInsertBarUpdateFoo ON Bar FOR INSERTAS UPDATE Foo SET lastUpdated = inserted.updated, lastValue = inserted.[Value] WHERE foo.fooID = inserted.fooIDGO
I get the error message:
Msg 4104, Level 16, State 1, Procedure onInsertBarUpdateFoo, Line 4 The multi-part identifier "inserted.fooID" could not be bound.
I can get the trigger to work fine as long as I don't reference "inserted".
What am I missing?
I'm using Microsoft SQL Server Management Studio Express 9.00.2047.00 and SQL Express 9.0.1399
