How do I alter a column check constraint?
I have the table:
CREATE TABLE Mytable(
mykey integer,
mycol integer
CHECK(mycol BETWEEN 1 AND 2)
PRIMARY KEY(mykey))
How do I change the constraint to
CHECK(mycol BETWEEN 0 AND 2)
...without losing any data?
Thanks!
Jim
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)
)
.
Can anyone please tell me how can i create a uniqueness contraint on part of column and index that part too. i.e.
consider the following table.
table A
Col1
furadfaf
fsradfasd
dddafadsf
hjfhdfjakdj
now i want only left three characters of the Col1 to be unique and indexed.
any idea ??????
When generating a check constraint to guarantee that a character column cannot be blank is it best to use comparison operators such as col1 <> '' or to use LEN(col1) > 0? Note that the column in marked as not nullable.
View 5 Replies View RelatedTable ATable B
AIDBID
Col 1BCol1
Col 2
Col3
I want to put a check constraint on A.col3 that depends on the values of A.Col1, A.Col2 and B.BCol1
How can I achieve this without using function.
Let's say I create a multi-statement function like this:CREATE FUNCTION dbo.Test ()RETURNS @res TABLE (N int NOT NULL CHECK (N >= 0))ASBEGININSERT INTO @resSELECT 1RETURNENDThat works fine. Then I make a change in the function's body, replace theCREATE FUNCTION with ALTER FUNCTION, and execute the batch. I get an error:Server: Msg 3729, Level 16, State 3, Procedure Test, Line 9Cannot ALTER 'dbo.Test' because it is being referenced by object'CK__Test__N__5D2E32EB'.Indeed, if I look at the list of dependencies for the function in QA'sobject tree, I can see the check constraint referenced in the errormessage.ALTER FUNCTION works fine if I don't specify the CHECK constraint in thedefinition of the @res table.So it seems that the only way to modify such a function is to drop andrecreate. Is that a known behavior? Is there any particular reason for it?Thanks.--(remove a 9 to reply by email)
View 1 Replies View RelatedCan anyone show how to alter the value in a column using DerivedColumn component when creating an SSIS package programatically.
View 4 Replies View Relatedsomehow I am not able to figure this out.
How do I change a computed column using the ALTER TABLE ALTER COLUMN... command?
I have been looking in the SQL Server Help Files, but I cant seem to find the syntax to change the name of a column name..?
Can it be done? if so, what is the syntax?
According to the MSDN, in SQL Server 2000
View 1 Replies View RelatedI have some columns of data in SQL server that are of NVARCHAR(420)format but they are dates. The dates are in DD/MM/YY format. I want tobe able to convert them to our accounting system format which isYYYYMMDD. I know the format is strange but it will make things easierin the long run if all of the dates are the same when working betweenthe 2 different databases. Basically, I need to take a look at theyear portion (with a SUBSTRING function maybe) to see if it is greaterthan 50 (there will not be any dates that are less than 1950) and ifit is concatenate 19 with it (ex. 65 = 1965). Then, concatenate themonth and day from the rest to form the date we need in NUMERIC(8).So, a date of January 17, 2003 (currently in the format of 17/01/03)would become 20030117. In VB, the function I would write is somethinglike the following:/*Dim sCurrentDate as StringDim sMon as stringDim sDay as StringDim sYear as StringDim sNewDate as StringsCurrentDate = "17/01/03"sMon = Mid(sCurrentDate, 4, 2)sDay = Mid(sCurrentDate, 1, 2)sYear = Mid(sCurrentDate, 7, 2)If sYear < 50 ThensYear = "20" & sYearElseIf sYear > 50 ThensYear = "19" & sYearEnd ifsNewDate = sYear & sMon & sDay*/I was thinking of doing this in a Stored Procedure but am really rustywith SQL (it's been since college).The datatype would end up being NUMERIC(8). How I would write it if Inew how to write it would be: grab the column name prior to theprocedure, create a temp column, format the values, place them intothe temp column, delete the old column, and then rename the tempcolumn to the name of the column that I grabbed in the beginning ofthe procedure. Most likely this is the only way to do it but I have noidea how to go about it.
View 1 Replies View RelatedHi 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 implement a constraint on a talbe for two fields
phone numbers should b (###)###-####
and ss# should be ###-##-####
How can I create such constraint. I tried, but got an error message and could not save the table with the new changes.
Thanks
Ahmed
In SQL Server 2000, I want to apply a check constraint on a column type varchar that it is not duplicated. Could someone help me out with this?
Also, should I just make this column the primary key instead of an identity field being the primary key?
What is the performance difference by applying the constraint rather then just making it the primary key?
Mike B
I have an existing table with field ZIPCODE defined as VARCHAR(5).
I want to add a check constraint to allow only number from 0 to 9.
This is what I did but it gave me error:
alter table test
with check
add constraint ck_test
check (zip between '0' and '9')
error:
ALTER TABLE statement conflicted with COLUMN CHECK constraint 'ck_test'.
The conflict occurred in database 'lahdProperty', table 'test', column 'Zip'.
What did I do wrong. Thanks for your help.
Hi,
I am creating a table in which i want a column to contain only these characters..ie
alphabets from a-z
alphabets from A-Z
numbers from 0-9
and allow characters
@
_ underscore..
.
- hyphen
ie suppose i have table called login..and i have 2 columns in this table named
Loginid LoginName...
So LoginName shuld accept only the above characters.while inserting data into this table..
Kindly 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.
Any help will be greatly appreciated.
Kind Regards
Carel Greaves
Hi,
If I diseable a Foreign Key like this:
Alter table table_name nocheck constraint constraint_name
I'm able to insert inconsitent data, then when I restart the contraint like this:
Alter table table_name check constraint constraint_name
the constraint dont check the current integrity of the data,
exist any way, without having to recreate the foreign key, to check the data integrity?
Thanks
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.
Is this possible and how can it be done?
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.
Hi,
I need list out the defaulat and constraint value in SQL2K. Where I get those values.
Thanks,
Ravi
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
Thanks!
Before adding a record this must check that in the column machine_id not twice the same machines are listed
Can someone help me?
Thanx and cheerz Wim
Hi
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.
Is this possible?
Thanking you in Advance!!!
Hi
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.
Is this possible?
Thanking you in advance!
I have a table called tblImages with the following columns:
ImageID [int]
UserID [int]
MainImg [bit]
what i need to ensure is that only one MainImage can be = 1 (true) for each userId at any one time.
any idea what i need to do?
alex
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 '%@%');
...but
ORA-02293: cannot validate (C3267304.Q_CHK_CUS_EMAIL) - check constraint violated
2. Tried from a forum: alter table Q_CUSTOMER
add constraint Q_Chk_cus_email check (Cus_email like '%_@__%.__%')
...but
ORA-02293: cannot validate (C3267304.Q_CHK_CUS_EMAIL) - check constraint violated
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
[code]....
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 ?
Thanks ...
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
View 3 Replies View RelatedCan 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);
View 3 Replies View Related