Solved

Overcome 8000 character varchar limit

Posted on 2004-09-03
17
561 Views
Last Modified: 2013-12-03

Our ASP.Net/VB online application allows users to create a customized query to run against a SQL Server 2000 database. The query string is created by passing parameters to a sproc which then assembles the query string and runs it.

When the user selects very many fields for return, this limit is exceeded, and one of the parameters passed from ASP.Net is truncated. Therefore the query string is not constructed and the query can't run.

This can't be the first time this has ever happened, so... what datatype can I use to pass a value when it exceeds 8000 characters? Text? User-defined data type? If so, how?

Thanks
0
Comment
Question by:k3n51mm
  • 6
  • 4
  • 3
  • +2
17 Comments
 
LVL 10

Expert Comment

by:AustinSeven
ID: 11973923
text/ntext is the only option I can think of.

AustinSeven
0
 
LVL 1

Author Comment

by:k3n51mm
ID: 11974065
Well, that's nice.

How do I do it?  What I mean is, okay, so I change the datatype to text in ASP.Net. Then when I pass it to SQL Server, I have a text parameter that is holding data that I have to use in a query. How do I manipulate the text so I can use it? This query has to be dynamically created on the SQL server and then executed. Can I simply insert the test into the query string? I've been told this is not possible.
0
 
LVL 34

Expert Comment

by:arbert
ID: 11974118
Just pass multiple varchar(8000) and concat them together when you do the query string....
0
U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

 
LVL 1

Author Comment

by:k3n51mm
ID: 11974155

That means dynamically adding parameters in 12 different places in the ASP code and seems too complex and inelegant. Since this is a database issue, should we really be fixing it in the business logic? Isn't there any way the SQL Server can handle this?
0
 
LVL 75

Expert Comment

by:Anthony Perkins
ID: 11974196
>>Since this is a database issue, should we really be fixing it in the business logic? <<
Correct. This is a design issue, there very rarely is a need to do this: "The query string is created by passing parameters to a sproc which then assembles the query string and runs it."

>>Isn't there any way the SQL Server can handle this?<<
Other than what arbert has suggested, not really.
0
 
LVL 75

Expert Comment

by:Anthony Perkins
ID: 11974209
Try posting your query and we may be able to give you more intelligent answers.
0
 
LVL 34

Expert Comment

by:arbert
ID: 11974228
"That means dynamically adding parameters in 12 different places in the ASP code and seems too complex and inelegant. Since this is a database issue, should we really be fixing it in the business logic? Isn't there any way the SQL Server can handle this?"

This isn't a database issue--this is a design issue--you should have known the limitations when the application was coded and coded appropriately....

0
 
LVL 18

Accepted Solution

by:
ShogunWade earned 250 total points
ID: 11974675
if the requirement is to simply execute a dynamic sql string bigger than 8000 chars take a look at

xp_exec resultset

its undocumented but this is basically how it works....

2 parameters 1) a query which returns aSQL statement  and 2nd a DB name to run it on.

eg:


xp_execresultset 'SELECT MyQuery FROM MyTable','MyDb'

the result of 'SELECT MyQuery FROM MyTable'  would form the query to execute on MyDb



0
 
LVL 18

Expert Comment

by:ShogunWade
ID: 11974688
example:



create table b(a varchar(8000),i int)
go

insert b values ('select *',1)
insert b values ('from sysobjects',2)


master.dbo.xp_execresultset 'Select a from b order by i','pubs'

0
 
LVL 18

Expert Comment

by:ShogunWade
ID: 11974704
using this you can "theortically" issue a command on upto 16Tb large    :)
0
 
LVL 34

Expert Comment

by:arbert
ID: 11974770
Not quite--it would still fall under the "Maximum Capacity Specifications" in books online....
0
 
LVL 18

Expert Comment

by:ShogunWade
ID: 11974789
indeed, quite correct arbert.

PS. i should have stressed in capitals the UNDOCUMENTED word.  
0
 
LVL 18

Expert Comment

by:ShogunWade
ID: 11974854
256 Meg based on default 4K packet size.   I suspect if you need a query that's bigger than that then you have bigger issues than query size ;)
0
 
LVL 1

Author Comment

by:k3n51mm
ID: 11974898

>>This isn't a database issue--this is a design issue--you should have known the limitations when the application was coded and coded appropriately....<<

How to lose points and influence people.



>>xp_execresultset 'SELECT MyQuery FROM MyTable','MyDb'<<

How to answer the frickin' question.

Thank you all
0
 
LVL 18

Expert Comment

by:ShogunWade
ID: 11974983
glad i could help k3.
0
 
LVL 34

Expert Comment

by:arbert
ID: 11975030
"How to lose points and influence people."

You also shouldn't post in the database area and post flat out that it's a database issue/problem...and you never did post your query or what you were trying to do like acperkins requested above--there are documented workarounds that you can use.....
0
 
LVL 75

Expert Comment

by:Anthony Perkins
ID: 11976013
>>How to lose points and influence people.<<
Please take the time to re-read the EE Guidelines.  Specifically this: "Remember, the Expert helping you today is probably going to be helping you next time you post a question."

See you next time ...
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Having an SQL database can be a big investment for a small company. Hardware, setup and of course, the price of software all add up to a big bill that some companies may not be able to absorb.  Luckily, there is a free version SQL Express, but does …
Load balancing is the method of dividing the total amount of work performed by one computer between two or more computers. Its aim is to get more work done in the same amount of time, ensuring that all the users get served faster.
Familiarize people with the process of retrieving data from SQL Server using an Access pass-thru query. Microsoft Access is a very powerful client/server development tool. One of the ways that you can retrieve data from a SQL Server is by using a pa…
Viewers will learn how to use the INSERT statement to insert data into their tables. It will also introduce the NULL statement, to show them what happens when no value is giving for any given column.

822 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question