We use SQL 7.0 and I want to know some guideline for choosing varchar or char data type. I heard that varchar takes more computation than char, then we should use all character type as a char. If then, it will takes more storage, so Is there any guideline for choosing varchar data type?
And also, Is the NULL value type same as varchar data type ?
How may extra bits does a NULL column contain.And how many extra bits does a varchar column contain.(I 've worked with Ingres and in that environment it both needed 2 extrabits)Bye,Arno de Jong, The Netherlands
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I have a stored procedure that accepts a parameter of type varchar(32). This parameter gets tested against NULL as part of an IF statement. The behavior I'm seeing is that this test never evaluates to TRUE, even in cases where NULL has been passed in as the value of the parameter.
CREATE PROCEDURE uspNewVital
@Description varchar(32),
@Type tinyint,
@DeviceType varchar(32),
@Dimension varchar(32),
@Unit varchar(32)
AS
IF (@Dimension != NULL AND @Unit != NULL)
BEGIN
RAISERROR ('You must specify either a dimension or a unit.', 15, 1) ;
RETURN 0 ;
END
IF NULL = @Dimension
BEGIN
DECLARE @UnitID AS int ;
SELECT @UnitID = ID FROM tblUnit WHERE Description=@Unit ;
IF @@ROWCOUNT = 0
BEGIN
RAISERROR ('Unit not found.', 15, 1) ;
RETURN 0 ;
END
INSERT INTO tblVitalType VALUES (@DeviceTypeID, @DatumID, NULL, @UnitID) ;
END
ELSE
BEGIN
DECLARE @DimensionID AS int ;
SELECT @DimensionID = ID FROM tblDimension WHERE Description=@Dimension ;
IF @@ROWCOUNT = 0
BEGIN
RAISERROR ('Dimension not found.', 15, 1) ;
RETURN 0 ;
END
INSERT INTO tblVitalType VALUES (@DeviceTypeID, @DatumID, @DimensionID, NULL) ;
END
GO
When I pass in a NULL for @Dimension, code execution still goes to the ELSE block.
At first I thought this might have something to do with the ANSI_NULLS option, but the database has this defaulting to OFF.
Any insights would be greatly appreciated. Thank you.
Hi, I have the following query
SELECT *
FROM PABX
INNER JOIN LOGIN ON (PABX.COD_CLIENTE = LOGIN.COD_CLIENTE)
AND LEFT(LOGIN.TELEFONE1,3) = LEFT(PABX.NRTELEFONE,3)
LEFT JOIN AUXILIAR ON (AUXILIAR.ORIGEM=LOGIN.LOCALIDADE)
WHERE
pabx.COD_cliente = 224 and
SUBSTRING(PABX.NRTELEFONE,4,1) NOT IN ('9', '8', '7')
AND LOGIN.UF = RIGHT(PABX.LOCALIDADE,2)
AND LOGIN.LOCALIDADE <> PABX.LOCALIDADE
AND PABX.CLASSIFICA IS NULL
AND PABX.LOCALIDADE <> AUXILIAR.DESTINO
AND (BLOQUEADO = 0 OR BLOQUEADO IS NULL)
But It has a problem because when AUXILIAR.DESTINO returns null (it means there is no registry) the condition AND PABX.LOCALIDADE <> AUXILIAR.DESTINO doesn't work, like 'SAO PAULO' is different from 'NULL' but for my query no it's not even equal, and this condition ommit the results....how can I solve it ?
PS: Both auxiliar.destino and pabx.localidade is varchar(255)
Thanks
Hi,
Anybody have any idea howmuch % of performance will be affect if we are using varchar instead of char data type?.
Thanks,
Ravi
We have few stored procedures that use nvarchar datatype, this was not issue on SQL server 7.0 but in 2000 becomes a big issue.
For example query that runs for 3 minutes in SQL server 2000 by replacing NVARCHAR to VARCHAR the same query runs for 2 seconds.
The biggest challenge that I have deals with tables and user-defined datatypes of NVARCHAR that has been bounded to the table.
How can I alter those without data corruption?
Any idea on performance comparison between VARCHAR and CLOB? For example, if I want to insert or update 4000 characters in a field of a row and I am confused whether that column's type would better be decalred as VARCHAR or CLOB, what do you suggest?
View 1 Replies View RelatedDoes using varchar in SQL Server 2005 significantly affect performance on updates?
Why or why not?
I have seen many SQL Server databases with many varchar columns - in other databases other than SQL Server it is advised not to use varchar because it significantly impacts performance.
I am trying to weigh when to waste space to help performance.
If I have a table
CREATE TABLE [dbo].[logg](
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[Details] [varchar](MAX) NULL)
insert logg (Details) values('')
insert logg (Details) values(null)
Will both statements above access only a single page (as it fits into one page) or does the VARCHAR(MAX) always put its data on a separate page. If so, is the null insert treated differently from the '' insert?
Hi there, I've a question regaarding datatype conversions... I can't convert the above mentioned datatype. I always get an error message that the conversion fails. Doesn't matter If convert or cast is used.
How would you convert the above mentioned variable into float???
I am using version 9.00.2047.00 SP1 of Visual Studio 2005.
Using ADO.NET, I have been unable to get the Execute SQL task to successfully return the value of an output parameter defined as varchar or nvarchar when the value is null. No other data types seem to have this problem, including the sql_variant data type.
Here is the stored procedure I am calling:
create proc spx
@in int = null output,
@vc nvarchar(10) = null output,
@dt datetime = null output
as
select
@in = null,
@vc = null,
@dt = null
return
The variables to which the three output parameters return their values have a data type of Object. The task runs fine when the integer or datetime parameters are used, and the variables can be identified as null using IsDBNull. But as soon as the nvarchar (or varchar) parameter is included, the task fails with this message:
"The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Parameter 1 ("@vc"): Data type 0xE7 has an invalid data length or metadata length."
I have seen a couple of postings that sound similar to this problem, but so far I have found no resolution. Any advice would be much appreciated.
Thanks,
Ron Rice
Hi, i'm new to SSIS and trying to import some csv files (comma delimited) into SQL Server. A NULL value for a CHAR column is correctly regonized as NULl in SQL Server, but a NULL value for of a mapping to a VARCHAR column in SQL Server is not recognized correctly and i get the value "'NULL'" in SQL Server (including the single comma.
Sample:
CSV file contains columns A and B. A and B contains the Text NULL.
Column A is mapped to a CHAR field, and column B is mapped to a VARCHAR field in SQL Server.
After the import, SQL has the following value: A = NULL as NULL, B 'NULL' as text.
did anyone else had this problem?
thanks so much for any help.
Hi,
My package dumps the errors into a table. The problem is, it couldnt dump Error Output column to a varchar field. I have added an script component in between to transform to string but no success.
I tried ErrorOutput.GetBlobData(0, ErrorOutput.Length)
but when I query the database, it says "System.Byte[]'
I will appreciate the responses to this post.
Thankyou,
Fahad
Hi,
What is the difference updating a null value to char/varchar type column
versus empty string to char/varchar type column?Which is the best to do and why?
Could anyone explain about this?
Example:
Table 1 : tCountry - Name varchar(80) nullable
Table 2 :tState - Name char(2) nullable
Table 3 :tCountryDetails - countryid,state (char(2) nullable) - May the country contain state or no state
So,when the state is not present for the country ,i have two options may be - null,''
tCountryDetails.State = '' or tCountryDetails.State = null?
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
I have looked far and wide and have not found anything that works to allow me to resolve this issue.
I am moving data from DB2 using the MS OLEDB Provider for DB2. The OLEDB source sees the column of data as DT_TEXT. I setup a destination to SQL Server 2005 and everything looks good until I try and run the package.
I get the error:
[OLE DB Source [277]] Error: An OLE DB error has occurred. Error code: 0x80040E21. An OLE DB record is available. Source: "Microsoft DB2 OLE DB Provider" Hresult: 0x80040E21 Description: "Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done.".
[OLE DB Source [277]] Error: Failed to retrieve long data for column "LIST_DATA_RCVD".
[OLE DB Source [277]] Error: There was an error with output column "LIST_DATA_RCVD" (324) on output "OLE DB Source Output" (287). The column status returned was: "DBSTATUS_UNAVAILABLE".
[OLE DB Source [277]] Error: The "output column "LIST_DATA_RCVD" (324)" failed because error code 0xC0209071 occurred, and the error row disposition on "output column "LIST_DATA_RCVD" (324)" specifies failure on error. An error occurred on the specified object of the specified component.
[DTS.Pipeline] Error: The PrimeOutput method on component "OLE DB Source" (277) returned error code 0xC0209029. The component returned a failure code when the pipeline engine called PrimeOutput(). The meaning of the failure code is defined by the component, but the error is fatal and the pipeline stopped executing.
Any suggestions on how I can get the large string data in the varchar column in DB2 into the varchar(max) column in SQL Server 2005?
I am trying to create a store procedure inside of SQL Management Studio console and I kept getting errors. Here's my store procedure.
Code Block
CREATE PROCEDURE [dbo].[sqlOutlookSearch]
-- Add the parameters for the stored procedure here
@OLIssueID int = NULL,
@searchString varchar(1000) = NULL
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- Insert statements for procedure here
IF @OLIssueID <> 11111
SELECT * FROM [OLissue], [Outlook]
WHERE [OLissue].[issueID] = @OLIssueID AND [OLissue].[issueID] = [Outlook].[issueID] AND [Outlook].[contents] LIKE + ''%'' + @searchString + ''%''
ELSE
SELECT * FROM [Outlook]
WHERE [Outlook].[contents] LIKE + ''%'' + @searchString + ''%''
END
And the error I kept getting is:
Msg 402, Level 16, State 1, Procedure sqlOutlookSearch, Line 18
The data types varchar and varchar are incompatible in the modulo operator.
Msg 402, Level 16, State 1, Procedure sqlOutlookSearch, Line 21
The data types varchar and varchar are incompatible in the modulo operator.
Any help is appreciated.
For the life of me I cannot figure out why SSIS will not convert varchar data. instead of using the table to table method, I wrote a SQL query so that I could transform the datatype ntext to varchar 512 understanding that natively MS is going towards all Unicode applications.
The source fields from Access are int, int, int and varchar(512). The same is true of the destination within SQL Server 2005. the field 'Answer' is the varchar field in question....
I get the following error
Validating (Error)
Messages
Error 0xc02020f6: Data Flow Task: Column "Answer" cannot convert between unicode and non-unicode string data types.
(SQL Server Import and Export Wizard)
Error 0xc004706b: Data Flow Task: "component "Destination - Query" (28)" failed validation and returned validation status "VS_ISBROKEN".
(SQL Server Import and Export Wizard)
Error 0xc004700c: Data Flow Task: One or more component failed validation.
(SQL Server Import and Export Wizard)
Error 0xc0024107: Data Flow Task: There were errors during task validation.
(SQL Server Import and Export Wizard)
DTS used to be a very strong tool but a simple import such as this is causing me extreme grief and wondering of SQL2005 is ready for primetime. FYI SP1 is installed. I am running this from a workstation and not on the server if that makes a difference...
Any help would be appreciated.
I have a table that contains a lot of demographic information. The data is usually small (<20 chars) but ocassionally needs to handle large values (250 chars). Right now its set up for varchar(max) and I don't think I want to do this.
How does varchar(max) store info differently from varchar(250)? Either way doesn't it have to hold the container information? So the word "Crackers" have 8 characters to it and information sayings its 8 characters long in both cases. This meaning its taking up same amount of space?
Also my concern will be running queries off of it, does a varchar(max) choke up queries because the fields cannot be properly analyzed? Is varchar(250) any better?
Should I just go with char(250) and watch my db size explode?
Usually the data that is 250 characters contain a lot of blank space that is removed using a SPROC so its not usually 250 characters for long.
Any insight to this would be appreciated.
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.
1. Use mssql server agent service to take the schedule
2. Use a .NET windows service with timers to call SqlClientConnection
above, which way would be faster and get a better performance?
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.
Hello Everyone,I have a very complex performance issue with our production database.Here's the scenario. We have a production webserver server and adevelopment web server. Both are running SQL Server 2000.I encounted various performance issues with the production server with aparticular query. It would take approximately 22 seconds to return 100rows, thats about 0.22 seconds per row. Note: I ran the query in singleuser mode. So I tested the query on the Development server by taking abackup (.dmp) of the database and moving it onto the dev server. I ranthe same query and found that it ran in less than a second.I took a look at the query execution plan and I found that they we'rethe exact same in both cases.Then I took a look at the various index's, and again I found nodifferences in the table indices.If both databases are identical, I'm assumeing that the issue is relatedto some external hardware issue like: disk space, memory etc. Or couldit be OS software related issues, like service packs, SQL Serverconfiguations etc.Here's what I've done to rule out some obvious hardware issues on theprod server:1. Moved all extraneous files to a secondary harddrive to free up spaceon the primary harddrive. There is 55gb's of free space on the disk.2. Applied SQL Server SP4 service packs3. Defragmented the primary harddrive4. Applied all Windows Server 2003 updatesHere is the prod servers system specs:2x Intel Xeon 2.67GHZTotal Physical Memory 2GB, Available Physical Memory 815MBWindows Server 2003 SE /w SP1Here is the dev serers system specs:2x Intel Xeon 2.80GHz2GB DDR2-SDRAMWindows Server 2003 SE /w SP1I'm not sure what else to do, the query performance is an order ofmagnitude difference and I can't explain it. To me its is a hardware oroperating system related issue.Any Ideas would help me greatly!Thanks,Brian T*** Sent via Developersdex http://www.developersdex.com ***
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Hey,
I was doing some research on how SQL stores data on disk.
MSDN states that when storring a varchar, only the length of the data itself is used plus two bytes.
So, if you store "car" in a VarChar(50) it will take 5 bytes.
But when you store "car" in a VarChar(500) it will also take 5 bytes.
What is the reason users should define the parameter lenght?
Can you use VarChar(8000) whole the time, without any drawback?
Thanks
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.
Hello.
I've built a sample CLR function with the following declaration....
CREATE FUNCTION GetManager(@DeptCode nvarchar(3))
RETURNS nvarchar(1000)
WITH RETURNS NULL ON NULL INPUT
AS
EXTERNAL NAME Assembly1.[ClassLibrary1.MyVBClass].MyManager
And it works as expected, except when I use NULL:
DECLARE @MyManager nvarchar(1000)
EXEC @MyManager = dbo.GetManager NULL
PRINT @MyManager
It returns the value "Unknown" as it would have for any unknown DeptCode, as-programmed.
I'm of the theory it should have returned NULL without actually firing the function? Or is this only for non-CLR items... or stored procedures, not functions?