I'm sorry, I bet you get asked this ten times a day but I can't find the answer, In Access, you can make a field have a requirement for a unique entry, BUT it allows as many Nulls as you want (i.e. only check for Uniqueness if there is an entry).
How do you mimic this behaviour in SQL Server?
Hello !
for MS SQL 2000
how can i set an unique index on Serial column but only if Serial IS NOT NULL
CREATE UNIQUE INDEX [IX_Product] ON [Product]([Serial]) ON [PRIMARY]
i can have 100 rows with a NULL Serial
thank you
Hi everyone
I have a varchar column which may, or may not, contain a userID value. I want some way of saying "If the column has a value, it must be unique" But I can't find any way of doing it without SQL complaining about duplicate null values. Is there a way of doing this?
Thanks!
Can I create a unique constraint on a column that can contain null values?
I need the control of the non null values (must be unique)...null is Ok if there's more than one.
I tried creating a unique constraint but i'm getting the error (duplicate keys <null>)
Hi All,
I am having problems with unique contraint, say I have a table called customer
create table customer (
id int identity(1,1) not null,
name nvarchar(50) not null,
id_card_no nvarchar(20) unique,
);
so when I do mutilple null inserts
insert into customer(name, id_card_no)
values("Customer 1", NULL);
insert into customer(name, id_card_no)
values("Customer 2", NULL);
I get an error duplicated keys on the unique column.
In Oracle DB, unique columns are behaved a little different where multiple nulls are allowed in a unique column.
I know there are some tircks that you can do to allow multiple nulls in unique column in sql server(well, pretend to be) like creating a computed column, create a view and an index...
Are there any ways to archieve that in sql sever compact?
Hi All,
I am having problems with unique contraint, say I have a table called customer
create table customer (
id int identity(1,1) not null,
name nvarchar(50) not null,
id_card_no nvarchar(20) unique,
);
so when I do mutilple null inserts
insert into customer(name, id_card_no)
values("Customer 1", NULL);
insert into customer(name, id_card_no)
values("Customer 2", NULL);
I get an error duplicated keys on the unique column.
In Oracle DB, unique columns are behaved a little different where multiple nulls are allowed in a unique column.
I know there are some tircks that you can do to allow multiple nulls in unique column in sql server(well, pretend to be) like creating a computed column, create a view and an index...
Are there any ways to archieve that in sql sever compact?
After adding a Unique constraint to a database I cannot add more than one record with a null value for the constrained field. I've tried both adding the constraint to an empty table as well as a table with multiple null values already in the subject field; both efforts have failed.
According to BOL SQL-7 allows Unique Constraints on fields with Null values. Am I missing a step? I do need to allow nulls in the field yet ensure that when there is a non-null value it is unique.
The SQL statement I've used is: ALTER TABLE tbl_MasterUIC ADD CONSTRAINT uniquesamplenbr UNIQUE NONCLUSTERED (samplenbr)
Thanks for any and all suggestions
Hi all,
I am trying to add a unique index/constraint on a column that allows NULL values. The column does have NULL values and when I try to create a unique constraint, I get the following error.
CREATE UNIQUE INDEX terminated because a duplicate key was found for index ID 9. Most significant primary key is '<NULL>'.
Are'nt you allowed to create a UNIQUE constraint on a NULL column? Books Online says that you are allowed to create a unique constraint on NULL columns, then why am I getting this error.
Any help would be appreciated.
Thanks,
Amir
HI,
To create a unique constraint on a multiple nullable column, we need to create a view with not null column and and then create a unique index on that view.
Is this is the only way of doing ?
Thank you.
Why we the Unique Constraint doesn't allow the multiple null values in Sql Server?
View 2 Replies View RelatedI know this is probably a flick of a switch but I cannot figure out which switch. Setup is SQL Server / Stored Procedures / DAL / BLL(skipped for testing) / PL. The stored procedure queries from only one table and two columns are ignored because they are being phased out. I can run the stored procedure and preview the data in the DAL but when I create a page with an ODS linked to the DAL and a GridView I get this error. I checked every column that does not allow nulls and they all have values. I checked unique columns (ID is the only unique and is Identity=Yes in the table definition). I checked foreign-key columns for values that are not in the foreign table and there are none. Any ideas why do I get this?
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.
Hi,
I am getting the above error when trying to load a report into my Web Application, I have tracked the error down to one specific field in my database. Even though this field is a NVarChar field and is of size 30 it would seem that there is an issue returning the value from the field. I can write it into the database no problems but when I try to get it out of the database it returns the above error.
e.g
MOB 401.908.804 - Fails
0401.907.324 - okay
8239 9082 (pager) - fails
Anyone got an idea on how to fix this????
Regards..
Peter.
Hey. I need to substitute a value from a table if the input var is null. This is fine if the value coming from table is not null. But, it the table value is also null, it doesn't work. The problem I'm getting is in the isnull line which is in Dark green color because @inFileVersion is set to null explicitly and when the isnull function evaluates, value returned from DR.FileVersion is also null which is correct. I want the null=null to return true which is why i set ansi_nulls off. But it doesn't return anything. And the select statement should return something but in my case it returns null. If I comment the isnull statements in the where clause, everything works fine. Please tell me what am I doing wrong. Is it possible to do this without setting the ansi_nulls to off??? Thank you
set ansi_nulls off
go
declare
@inFileName VARCHAR (100),
@inFileSize INT,
@Id int,
@inlanguageid INT,
@inFileVersion VARCHAR (100),
@ExeState int
set @inFileName = 'A0006337.EXE'
set @inFileSize = 28796
set @Id= 1
set @inlanguageid =null
set @inFileVersion =NULL
set @ExeState =0
select Dr.StateID from table1 dR
where
DR.[FileName] = @inFileName
AND DR.FileSize =@inFileSize
AND DR.FileVersion = isnull(@inFileVersion,DR.FileVersion)
AND DR.languageid = isnull(@inlanguageid,null)
AND DR.[ID]= @ID
)
go
set ansi_nulls on
This index is not unique
ix_report_history_creative_id
Msg 2601, Level 14, State 1, Procedure DFP_report_load, Line 161
Cannot insert duplicate key row in object 'dbo.DFP_Reports_History' with unique index 'ix_report_history_creative_id'.
The duplicate key value is (40736326382, 1, 2015-07-03, 67618862, 355324).
Msg 3621, Level 0, State 0, Procedure DFP_report_load, Line 161
The statement has been terminated.
Exception in Task: Cannot insert duplicate key row in object 'dbo.DFP_Reports_History' with unique index 'ix_report_history_creative_id'. The duplicate key value is (40736326382, 1, 2015-07-03, 67618862, 355324).
The statement has been terminated.
A UNIQUE INDEX must inherently impose a unique constraint and a UNIQUE CONSTRAINT is most likely implemented via a UNIQUE INDEX. So what is the difference? When you create in Enterprise Manager you must select one or the other.
View 8 Replies View RelatedHelloWhat should I use for better perfomance sinceunique constraint always use index ?ThanksKamil
View 5 Replies View RelatedWhat's the difference in the effect of the followings:
CREATE UNIQUE NONCLUSTERED INDEX
and
ALTER TABLE dbo.titles ADD CONSTRAINT
titleind UNIQUE NONCLUSTERED
I found there're two settings in Indexs/Keys dialog box of the management studio, Is Unique, and Type. The DDL statements above are generated by setting Is Unique to yes plus Type to Index, and just Type to Unique Key, respectively. What's the difference between them?
Hi everyone,
I need urgent help to resolve this issue...
As far as the performance goes which one is better..
Unique Index(col1, col2) OR Unique constraint(col1, col2) ?
Unique constraint automatically adds a unique index
and unique index takes care of uniqueness then whats the use of unique constraint ?
Which one do one use ?
thanks
sonali
BOL says a unique constraint is preferred over a unique index. It also states that a unique constraint creates a unique index. What then is the difference between the two, and why is a constraint preferred over the index?
View 2 Replies View Related
hi team,
.Can i create umique constraint with out unique index.when i am creating a unique constraint sql creates a unique index (default) can i have only unique constraint ?
I am having a problem trying to figure out the best way to get the results I need. I have a table of part numbers that is joined with a table of notes. The table of notes is specific to the part number and user. A row in the notes table is only created if the user has entered notes on that part number. I need to create a search that grabs all matches on a keyword and returns the records. The problem is that it currently returns a row from the parts table with no notes and a separate row with the notes included if they had created an entry. It seems like this should be easy but it eludes me today.
Here is the code
Code Snippet
create procedure SearchPartKeyword
(
@Keyword varchar(250) = null,
@Universal_Id varchar(10) = null
)
as
select p.PartNumber, p.Description, p.ServiceOrderable, n.MyNotes, p.LargestAssembly, p.DMM,
p.Legacy, p.Folder, p.Printer
from Parts p inner join notes n on p.PartNumber = n.Identifier
where n.Universal_ID = @Universal_ID and p.Description like @Keyword
union
select p.PartNumber, p.Description, p.ServiceOrderable, '' as MyNotes, p.LargestAssembly,
p.DMM, p.Legacy, p.Folder, p.Printer
from Parts p
where p.Description like @Keyword
and the results:
PartNo Description SO Notes LA DMM Legacy Folder Printer
de90008 MAIN BOARD 1 DGF1 114688 0 0 0
de90008 MAIN BOARD 1 I love this part Really I do DGF1 114688 0 0 0
This could return multiple part numbers and If they have entered notes I want the row with the notes
Thank You
Dominic Mancl
What 's difference between Unique key and unique index in SQL server 2005?
View 9 Replies View RelatedHere is the table I created:
create table Test (
[recId] [int] identity(1, 1) not null,
[code] [varchar](50) not null,
[prime] [bit] not null constraint [DF_Test_prime] default (cast(0 as bit)),
constraint [PK_Test] primary key clustered
(
[recId]
) with fillfactor = 90 on [primary]
) on [primary]
go
insert into Test (code, prime) values ('AVA', cast(1 as bit))
insert into Test (code, prime) values ('BUS', cast(1 as bit))
insert into Test (code, prime) values ('BUS', cast(0 as bit))
insert into Test (code, prime) values ('BUS', cast(0 as bit))
insert into Test (code, prime) values ('CAR', cast(1 as bit))
insert into Test (code, prime) values ('CAR', cast(0 as bit))
insert into Test (code, prime) values ('RLW', cast(1 as bit))
insert into Test (code, prime) values ('RLW', cast(0 as bit))
insert into Test (code, prime) values ('RLW', cast(0 as bit))
select *
from Test
I need to create a constraint on this table that will not allow me to have two rows that are prime for the same code. So the following insert statement should fail:
-- This should fail
insert into Test (code, prime) values ('RLW', cast(1 as bit))
Thanks for you help!
Regards,
Anand
In my report i have CNAME parameter , which allows null value. I checked Allow null value check box in report parameter properties.
when i preview the report , it displays checked NULL check box beside CNAME parameter . I want to give some meaningful name(i.e.ALLCustomers) to this checkbox instead of NULL.
Is it possible through SSRS designer?
I have a flat file with the following columns
SampleID Rep_Number Product Protein Fat Solids
In the flat file SampleID and Product are populated in the first row only, rest of the rows only have values for Rep_Number, Protein, Fat, Solids.
SampleID and Product are blank for the rest of the rows. So my task is to fill those blank rows with the first row that has the sampleID and Product and load into the table.
I have a report that is run on a monthly basis with a default date of null. The stored procedure determines the month-end date that it should use should it be sent a null date.
The report works fine when I tell it to create a history entry; however, when I try to add a subscription it doesn't appear to like the null parameter value. Since I have told the report to have a default value of null it doesn't allow me to enter a value on the subscription page.
Now, I suppose I could remove the parameter altogether from the stored proc, but then the users would never be able to run the report for a previous time period. Can someone explain to me why default values aren't allowed to be used on subscriptions when they seem to work fine for ad hoc and scheduled reports? This is really quite frustrating as most of my reports require a date value and default to null so that the user doesn't have to enter them for the latest data.
An internal error occurred on the report server. See the error log for more details. (rsInternalError) Get Online Help
Key cannot be null. Parameter name: key
I run a stored procedure for which I have a return variable. The stored procedure returns the ID of a row in a table if it exists:
m_sqlCmd.ExecuteScalar();
The m_sqlCmd has been fed an SQLParameter with direction set to output.
When the stored proc returns, I want to test it. Now when there IS a row it returns the ID ok.
When the row doesn't exist, in my watch I have:
m_sqlParam.SqlValue with value {Null}
I can't seem to work out how to test this value out.
I've tried several things but none seem to work.
This line compiles ok, but the following runs into the IF statement as if the SqlValue is null??
if (m_sqlParam.SqlValue != null)....
{
// I'm here!! I thought the watch says this is null???
}
Sorry if this is obvious, but I can't work this one out!!
Looks like there was a fix and then I read this fix is not a fix. Does anyone know how this can be rectified? Does it mean that only Windows authentiation is the only way it works. The Software is over 2 years old, there are no excuses.
I am getting this error: "Cannot insert the value NULL into column 'OrderID', table 'outman.outman.Contact'; column does not allow nulls. INSERT fails." -- But my value is not null. I did a response.write on it and it show the value. Of course, it would be nice if I could do a breakpoint but that doesn't seem to be working. I'll attach a couple of images below of my code, the error, and the breakpoint error.
Server Error in '/' Application.
Cannot insert the value NULL into column 'OrderID', table 'outman.outman.Contact'; column does not allow nulls. INSERT fails.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: Cannot insert the value NULL into column 'OrderID', table 'outman.outman.Contact'; column does not allow nulls. INSERT fails.Source Error:
Line 89: sContact.Phone = sPhone.Text.Trim
Line 90: sContact.Email = sEmail.Text.Trim
Line 91: sContact.Save()
Line 92:
Line 93: Dim bContact As Contact = New Contact()Source File: F:InetpubwwwrootOutman KnifeCheckout.aspx.vb Line: 91 Stack Trace:
[SqlException (0x80131904): Cannot insert the value NULL into column 'OrderID', table 'outman.outman.Contact'; column does not allow nulls. INSERT fails.]
System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +857354
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +734966
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +188
System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +1838
System.Data.SqlClient.SqlDataReader.HasMoreRows() +150
System.Data.SqlClient.SqlDataReader.ReadInternal(Boolean setTimeout) +214
System.Data.SqlClient.SqlDataReader.Read() +9
System.Data.SqlClient.SqlCommand.CompleteExecuteScalar(SqlDataReader ds, Boolean returnSqlValue) +39
System.Data.SqlClient.SqlCommand.ExecuteScalar() +148
SubSonic.SqlDataProvider.ExecuteScalar(QueryCommand qry) +209
SubSonic.DataService.ExecuteScalar(QueryCommand cmd) +37
SubSonic.ActiveRecord`1.Save(String userName) +120
SubSonic.ActiveRecord`1.Save() +31
Checkout.btnCheckout_Click(Object sender, EventArgs e) in F:InetpubwwwrootOutman KnifeCheckout.aspx.vb:91
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102
Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.42
I would drop and add the table but the data can't be deleted. So if anyone could help with the statement it would be greatly appreciated. Thanks
View 7 Replies View RelatedI'm trying to set the concat... option to OFF
all the time and in all my databases
I tried this command
USE master
EXEC sp_dboption 'DatabaseName', 'concat null yields null', 'FALSE'
but it doesn't change anything
Select NULL + 'TOTO'
----> NULL
(it should be 'TOTO')
hi,my structure table in database:Amount float(53) not null default 0when i try to run his script:alter table ABC alter column Amount float(53) nullit can only set the Amount to allow null, but can't set the defaultvalue to empty.anyone know how to set the field to allow null and default set toempty, no value.thanks
View 5 Replies View RelatedIt's giving me an error while I'm trying to change column value from not null to null..
'tblid' table
- Unable to modify table.
Cannot insert the value NULL into column 'ValidID', table 'Xe01.dbo.Tmp_tblid'; column does not allow nulls. INSERT fails.
The statement has been terminated.