I'm faced with a dilemma regarding db design. I would like to have a generic table that links to many tables, but somehow still enforce integrity with a constraint.
Eg An ownership table, then various document tables eg Loan document table, budget document table. Both the load table and budget table are linked to the ownership table by their primary keys.
Ownership will have doc_id and doc_type columns. How do I enforce integrity ie the load_id = doc_id where doc_type = 'LOAN' and budget_id = doc_id where doc_type = 'BUDGET' are valid using a contraint? I believe check contraints cannot span across tables, is there a work around?
I know a simple solution would be to use separate ownership tables, but I would like to make it generic.
Hi Guys, Is it better to create all tables (in store procedure) and then another store procedure to create and apply all relationship between the tables??? , OR is it better to have each table relationship at the end of the store procedure to create that table and have each table relationship at the end of its create statement??? What are the Advantages and disadvantages of each method? Thanks,Mehdi
Hi I was wodering how to add an OR statment right in the Check Constraint expression. This is what I am starting with in the database ([zip] like '[0-9][0-9][0-9][0-9][0-9]') and what I want well not exact but this would answer my question ([zip] like '[0-9][0-9][0-9][0-9][0-9] || [A-Z][A-Z][A-Z][A-Z][A-Z]') Thanks for any help
Hi, i want to put a check constraint on one of my tables to make sure that a member doesn't get loaded into the same usergroup twice. Could anyone please help me with this.
Here is some sample code:
Code Block
DECLARE @MyTable TABLE (ID INT IDENTITY(1,1), MemberID INT, ClientID INT, UsergroupID INT) INSERT INTO @MyTable VALUES (123456, 211, 3054) -- Member gets loaded twice INSERT INTO @MyTable VALUES (123456, 211, 3054) INSERT INTO @MyTable VALUES (123456, 211, 3055) -- Same Member as the top but into ---- a different usergroup which is correct INSERT INTO @MyTable VALUES (215489, 376, 2017) INSERT INTO @MyTable VALUES (987512, 345, 2237) INSERT INTO @MyTable VALUES (235479, 333, 1158) INSERT INTO @MyTable VALUES (354985, 333, 1158)
SELECT * FROM @MyTable
The problem i have is that if a member is loaded into the same usergroup twice then the sites crash on the web applications and the member can't get into his profile page.Unfortunately i don't know which one of the 1000 stored procedures are used to access this table so that i could just change the query to SELECT TOP 1.
However i think that it will be better practive to just put a check contraint on the table and avoide the whole problem.
However 1 member can belong to multiple usergroups.
In our database we have an indexed field that is using unique values, so in the index we turned on the unique property. Now with some changes we made in the application this value can be Null (could not be Null in the past). When we have more as 1 value having value Null we get an exception of unique key violation.
Therefor we want to make an check constraint the checks if the value allready exists when the value is not Null.
Hi, I am trying to enforce a rule that only one record in a table can have status 'Active'. I'd like to do this with CHECK constraint rather than trigger. I know SQL server doesn't support subqueries such as : alter table add constraint chk_OnlyOneActive CHECK (1=(select count(*) from mytable where status='Active')) Is there any workaround for this? P.S. I tried using UDF like this: alter table add constraint chk_OnlyOneActive CHECK (dbo.NumActiveRecords()=1) and it works for insert - I am not able to insert a second "Active" record, but for some reason doesn't work for update - I am able to update existing record to status "Active" and end up with two or more Active records in the table. Thank you.
I am creating a check constraint on a field (GRID_NBR) for values between 1 & 99. I am a little confused on creating the expression for it (Books online is vague).
Can I use the following expression: GRID_NBR BETWEEN 1 AND 99
Or do I have to use: GRID_NBR > 0 AND GRID_NBR < 100
I have a table with 3 columns in it. The ID column has a datetime data type.
Does anyone know how to apply a check constraint on this field so that the same month cannot be entered twice.
For example the field has the following data in the field 26/04/2008 27/05/2008 26/06/2008 25/07/2008
A user then tries to enter the value 20/05/2008, I would like the check constraint to block this value being entered due to the fact that a item with the same month value has already been entered.
I have created a table which contains date periods. It has 3 fields all with DateTime data types. These fields being ID, BeginDate, and EndDate. The ID field will hold a date indicating what month the reord is for, ie 01/03/2007 being March or 05/04/2007 being April. The BeginDate will contain the beginnig date for the financial month and EndDate for the financial month.
I am trying to apply a check constraint on the ID field so that combaination of a month and year can only be entered once, ie. if 01/03/2007 already exists in the table then 03/03/2007 cannot.
I need to create a check constraint for an email column/field, where the field must contain an "@" symbol. Does sql (oracle or SQL in general) let you do this.
1. Tried myself: ALTER TABLE Q_Customer ADD CONSTRAINT Q_chk_Cus_email CHECK (Cus_email LIKE '%@%');
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
I am having some difficulties to find the documentation relative to the syntax of CHECK and CONTRAINT in MS SQL Server 2005. Can someone points me toward a reference guide?
Thanks in advance, Joannès http://www.peoplewords.com
Hi , I have a table that holds CityName and TownName.This table is usually updated and I dont want the same CityName and TownName to be inserted Again. I have used Primary Key that holds thoose two fields but Primary Key is an index and I know that using check constraint works by spending less performance then indexes .
So , How can I use a check Constraint for two fields ?
Hi there, My problem should be fairly simple. Say i have a small table with 2 columns, employee_id and department_id. I want to create a check constraint so that no more than 4 employee_id can be associated with department_id and the user is warned if he/she is trying to do so. Can anyone advise me on how to do it? Regards, Kam
Hi,I am new to database development and am writing a database as part of auniversity courseI have created a table as below called CableWire - the table is created ok.CREATE TABLE CableWire(CableWireID CHAR(7),BSstandard CHAR(16),Colour VARCHAR(16),Material VARCHAR(16),MetresInStock INTEGER,PRIMARY KEY (CableWireID));However when I try to alter the table by adding a CHECK constraint:ALTER TABLE CableWireADD CHECK (MetresInStock >= 0);I get a pop-up box: "Line: 21SQLSTATE = 37000[Microsoft][ODBC dBase Driver] Syntax error in field definition, Continue?"(line 21 equated to the 2nd of those 2 lines). The syntax seems perfectlyacceptable to me. Any help appreciated.Regards,Mary
Can we use parentheses in a check constraint in MS-SQL-server DDL?e.g. I'm having a problem with the following statement:ALTER TABLE [dbo].[MyTable] ADD CONSTRAINT [CK_MyTable_TimesDataOK]CHECK (([TimeOn] IS NULL AND [TimeOff] IS NULL)OR([ShiftCode] IS NOT NULL AND [TimeOn] IS NOT NULL AND [TimeOff] IS NOTNULL));The statement appears to run fine, but when I look at my tabledefinition afterwards, it appears that SQL-server ignored theparentheses in my constraint; it shows the constraint expression as:(([TimeOn] IS NULL AND [TimeOff] IS NULL OR [ShiftCode] IS NOT NULL AND[TimeOn] IS NOT NULL AND [TimeOff] IS NOT NULL))My intention is that if there's (non null) data in either of the columnsTimeOn or TimeOff is not null, all three of the columns TimeOn, TimeOffand ShiftCode must have non null data.OK, I realise I could enforce this by altering my table setup in otherways. Right now I'm just trying to figure out if this I'm just upagainst a difference between dialects of SQL in check constraints here.Am I missing something obvious with parentheses?BTW the DDL for the table I'm testing on:CREATE TABLE [dbo].[MyTable]([FNname] [nvarchar](50) NOT NULL,[ShiftDate] [datetime] NOT NULL,[ShiftCode] [nchar](2) NULL,[TimeOn] [nchar](4) NULL,[TimeOff] [nchar](4) NULL);
I thought the whole point of 'check constraint' being unticked meant you could whack your data straight in no probs.
How can I insert a bunch of historical information where I want to control the PK, in this case DealID?
I have got 'keep identity' checked.
I check the db, the Id does NOT exist currently.
Error: 0xC0202009 at Data Cleansing, Deal Insert [12194]: SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005. An OLE DB record is available. Source: "Microsoft SQL Native Client" Hresult: 0x80004005 Description: "The statement has been terminated.". An OLE DB record is available. Source: "Microsoft SQL Native Client" Hresult: 0x80004005 Description: "Violation of PRIMARY KEY constraint 'PK_DealID'. Cannot insert duplicate key in object 'dbo.Deal'.".
What I want to do is write a constraint (or 4 constraints) that says: If AttributeDataType = 'nvarchar', AttributeLength cannot be NULL, AttributePrecision must be NULL, AttributeScale must be NULL If AttributeDataType = 'int', AttributeLength must be NULL, AttributePrecision must be NULL, AttributeScale must be NULL If AttributeDataType = 'datetime', AttributeLength must be NULL, AttributePrecision must be NULL, AttributeScale must be NULL If AttributeDataType = 'decimal', AttributeLength must be NULL, AttributePrecision cannot be NULL, AttributeScale cannot be NULL
Is that even possible? I've tried and failed (admittedly not for too long) to fathom a way of doing it.
I have created a table which contains date periods. It has 3 fields all with DateTime data types. These fields being ID, BeginDate, and EndDate. The ID field will hold a date indicating what month the reord is for, ie 01/03/2007 being March or 05/04/2007 being April. The BeginDate will contain the beginnig date for the financial month and EndDate for the financial month.
I am trying to apply a check constraint on the ID field so that combaination of a month and year can only be entered once, ie. if 01/03/2007 already exists in the table then 03/03/2007 cannot.
Hi, I need the T-SQL statement on how to raise a custom error message for a check contraint @au_id '[0-9][0-9][0-9]-[0-9][0-9][0-9][0-9][0-9][0-9]' when ever a client enters the wrong SSN format such as 575-444865. I used the t-sql statement below but does not work when running an insert on the authors table ; au_id column.
CREATE TRIGGER trg_datavalidate ON authors FOR INSERT AS DECLARE @au_id varchar(11) DECLARE @err INT
SELECT @err = @@ERROR from inserted IF @err = 547 BEGIN PRINT 'Au_id needs to be in the SSN format xxx-xx-xxxx!. Error Number:' + CAST(@err AS VARCHAR) RAISERROR ('au_id must be in the format of xxx-xxxxxx where x is a number.', -- Message text. 16, -- Severity. 1 -- State. ); ROLLBACK TRANSACTION END
Hi there. I really hope somebody can point out what's going wrong here..
Firstly, what I'm trying to do is ensure that when a user adds a row to one of my tables, lets call it a WorkDateRange table, that the dates entered never overlap for the same work.
This constraint needs to be created at the same time the Database is created. I'm using a function in the check constraint that is also created when the DB is.
This table will store types of work as an Int along with a start date and an end date for the range. eg. 9999 2008/04/01 2008/04/22, that would be a work type of 9999 and a date range of 2008/04/01 - 2008/04/22. Therefore a user should not be able to enter this as the next row entry, 9999 2008/04/12 2008/04/30, without violating the check constraint. Now thats all good in theory but in practise I just can't get it!
Here is the code I am using:
~first the DB is created~
<now the Function>
CREATE FUNCTION WorkDateRange_CheckDateOverlapping ( @Work INT, @Date DATETIME ) RETURNS BIT AS BEGIN DECLARE @LogicalValue BIT, @StartDate DATETIME, @EndDate DATETIME
DECLARE WorkDateRange_Cursor CURSOR FOR SELECT StartDateRange, EndDateRange FROM WorkDateRange WHERE Work = @Work
SET @LogicalValue = 1
OPEN WorkDateRange_Cursor FETCH NEXT FROM WorkDateRange_Cursor INTO @StartDate, @EndDate WHILE @@FETCH_STATUS = 0 BEGIN SELECT @LogicalValue = CASE WHEN @Date BETWEEN @StartDate AND @EndDate THEN 0 ELSE 1 END IF @LogicalValue = 0 BREAK
FETCH NEXT FROM WorkDateRange_Cursor INTO @StartDate, @EndDate END
CLOSE WorkDateRange_Cursor DEALLOCATE WorkDateRange_Cursor
RETURN @LogicalValue END GO
<Then the table is created with these columns and these constraints on StartDateRange and EndDateRange>
Columns: [UID] BIGINT, Work INT, StartDateRange DATETIME, EndDateRange DATETIME
When I create the database and tables all is successful, but when I try enter rows into the WorkDateRange table, I get a message that my check constraint is violated. But if I copy my code into a separate query and declare the Work and Date variables and assign them the values that would be assigned during the check. I get the desired result of 1, which should be passing the check.
Any help would be greatly appreciated Thanks in Advance.
I want to set up a simple check constraint on a column limiting to values "Yes", "No" and ""I'm trying to use:CONSTRAINT IsAccessToItRestricted_ckcheck (IsAccessToItRestricted in('Yes,'No','');but this is not the right syntax.............. help!
I receive the following error when creating a CHECK constraint that references another column. According to the good old Wrox SQL Server book, I'm using the correct syntax. Anyone have any ideas???
Thanks in advance!
Server: Msg 8141, Level 16, State 1, Line 1 Column CHECK constraint for column 'end_date' references another column, table 'Session'.
Here's an example of the script that I'm using: CREATE TABLE Session ( session_key char(18) NOT NULL, course_key char(18) NOT NULL, site_key char(18) NOT NULL, instructor_key char(18) NOT NULL, start_date smalldatetime NULL, end_date smalldatetime NULL CHECK (end_date >= start_date) )
Does anyone out there have succinct, efficient, & elegant CHECK constraints written for IP addresses & MACAddrs (w/ colons)? Nothing succinct, efficient, & elegant? Then how about something that works? Thanks!
