Query remote oracle CLOB data from MSSQL - sql

I read different posts about this problem but it didn't help me with my problem.
I am on a local db (Microsoft SQL Server) and query data on remote db (ORACLE).
In this data, there is a CLOB type.
CLOB type column shows me only 7 correct data the others show me <null>
I tried to CAST(DEQ_COMMENTAIRE_REFUS_IMPORT AS VARCHAR(4000))
I tried to SUBSTRING(DEQ_COMMENTAIRE_REFUS_IMPORT, 4000, 1)
Can you help me, please ?
Thank you

No MSSQL but in my case we were pulling data into MariaDB using the ODBC Connect engine from Oracle.
For CLOBs, we did the following (in outline):
Create PLSQL function get_clob_chunk ( clobin CLOB, chunkno NUMBER) RETURN VARCHAR2.
This will return the the specified nth chunk of 1000 chars for the CLOB.
We found 1,000 worked best with multibyte data. If the data is all plain text single byte that chunks of 4,000 are safe.
Apologies for the absence of actual code, as I'm a bit rushed for time.
Create a Oracle VIEW which calls the get_clob_chunk function to split the CLOB into 1,000 char chunk columns chunk1, chunk2, ... chunkn, CAST as VARCHAR2(1000).
We found that Oracle did not like having more than 16 such columns, so we had to split the views into sets of 16 such columns.
What this means is that you must check what the maximum size of data in the CLOB is so you know how many chunks/views you need. To do this dynamically adds complexity, needless to say.
Create a view in MariaDB querying the view.
Create table/view in MariaDB that joins the chunks up into a single Text column.
Note, in our case, we found that copying Text type columns between MariaDB databases using the ODBC Connect engine was also problematic, and required a similar splitting method.
Frankly, I'd rather use Java/C# for this.

Related

Export SQL Server linked server table with 334449 rows

I want to export the data from a table from linked server. The table has over 300,000 rows.
When I run this query:
SELECT *
FROM [LSERVER].[LTechnologies].[Connector].[MASD]
I get an error:
OLE DB provider 'MSDASQL' for linked server 'LSERVER' returned data that does not match expected data length for column '[LSERVER].[LTechnologies].[Connector].[MASD]'. The (maximum) expected data length is 8000, while the returned data length is 8448.
The source is NetSuite linked to MS SQL as ODBC Data Source.
Is there any way to work around this limitation?
Thanks
Is there any way to work around this limitation?
The typical workaround is to use OPENQUERY to send a "passthrough" query to the target system and ask it to perform type conversions to the types that actually work.
Haim, it sounds like a built limitation limiting varchar or nvarchar to 8K characters. I have seen this a couple times but never seen anyone beat it - normally we just exclude the column. However if it's worth the time, you could find the column and do a LEFT([column], 7999) to see if you can at least get most of the data back. Hope it helps.

Why do some string fields only have a single character when using Oracle heterogeneous services to pull view from SQL Server?

I have confirmed that the view returns the correct data when on the SQL Server. But when pulling the raw view through Oracle some of the string columns only contain 1 character for each record, while other columns are fully populated.
Does anyone know what could cause this issue?
The fields that had cutoff characters were NVARCHAR(50). Apparently, Oracle does not pull NVARCHARs correctly from SQL Server. Casting them as VARCHAR(50) in the SQL Server view solved the problem.

Search and Replace a a partial string / substring in mssql tables

I was tasked with moving an installation of Orchard CMS to a different server and domain. All the content (page content, menu structure, links, etc.) is stored in an MSSQL database. The good part: When moving the physical files of the Orchard installation to the new server, the database will stay the same, no need to migrate it. The bad thing: There are lots and lots of absolute URLs scattered all over the pages and menus.
I have isolated / pinned down the tables and fields in which the URLs occur, but I lack the (MS)SQL experience/knowledge to do a "search - replace". So I come here for help (I have tried exporting the tables to .sql files, doing a search-replace in a text editor, and then re-importing the .sql files to the database, but ran into several syntax errors... so i need to do this the "SQL way").
To give an example:
The table Common_BodyPartRecord has the field Text of type ntext that contains HTML content. I need to find every occurance of the partial string /oldserver.com/foo/ and replace it with /newserver.org/bar/. There can be multiple occurances of the pattern within the same table entry.
(In total I have 5 patterns that will need replacing, all partial string / substrings of urls, domains/paths, etc.)
I usually do frontend stuff and came to this assignment by chance. I have used MySQL back in the day I was playing around with PHP related stuff, but never got past eh basics of SQL - it would be helpful if you could keep your explainations more or less newbie-friendly.
The SQL server version is SQL Server 9.0.4053, I have access to the database via the Microsoft SQL Server Management Studio 12
Any help is highly appreciated!
You can't manipulate the NTEXT datatype directly, but you can CAST it to VARCHAR(MAX), then use the REPLACE function to perform the string replacement, then CAST it back to NTEXT. This can all be done in a single UPDATE statement.
update MyTable
set MyColmun = cast(replace(cast(MyColumn as nvarchar(max)), N'/oldserver.com/foo/', N'/newserver.org/bar/') as ntext)
where cast(MyColumn as nvarchar(max)) LIKE N'%/oldserver.com/foo/%'
The WHERE clause in the UPDATE statement below is used to prevent SQL Server from making non-changes, i.e. if the value does not need to be changed then there is no need to update it to itself.
The CAST function is used to change the data type of a value. NTEXT is a legacy data type used for storing large character values, NVARCHAR(MAX) is a new and more versatile data type for storing large character values. The REPLACE function can not operate on NTEXT values, hence the need to CAST it to NVARCHAR(MAX) first, do the replace, then CAST it back to NTEXT afterwards.

Create delimited string from a row in stored procedure with unknown number of elements

Using SQL Server 2000 and Microsoft SQL Server MS is there a way to create a delimited string based upon an unknown number of columns per row?
I'm pulling one row at a time from different tables and am going to store them in a column in another table.
A simple SQL query can't do anything like that. You need to specify the fields you are concatenating.
The only method that I'm aware of is to dynamincally build a query for each table.
I don't recall the structure of MSSQL2000, so I won't try to give an exact example, maybe someone else can. But there -are- system tables that contain table defintions. By parsing the contents of those system tables you can dynamically build the necessary query for each source data table.
TSQLthat writes TSQL, however, can be a bit tricky to debug and maintain :) So be careful how you structure everything...
Dems.
EDIT:
Or just do it in your client application.

Why is maximum length of varchar less than 8,000 bytes?

So I have a stored procedure in a SQLServer 2005 database, which retrieves data from a table, format the data as a string and put it into a varchar(max) output variable.
However, I notice that although len(s) reports the string to be > 8,000, the actual string I receive (via SQLServer output window) is always truncated to < 8,000 bytes.
Does anybody know what the causes of this might be ? Many thanks.
The output window itself is truncating your data, most likely. The variable itself holds the data but the window is showing only the first X characters.
If you were to read that output variable from, for instance, a .NET application, you'd see the full value.
Are you talking about in SQL Server Management Studio? If so, there are some options to control how many characters are returned (I only have 2008 in front of me, but the settings are in Tools|Options|Query Results|SQL Server|Results to Grid|Maximum Characters Retrieved and Results to Text|Maximum number of characters displayed in each column.
The data is all there, but management studio isn't displaying all of the data.
In cases like this, I've used MS Access to link to the table and read the data. It's sad that you have to use Access to view the data instead of Management Studio or Query Analyzer, but that seems to be the case.
However, I notice that although len(s) reports the string to be > 8,000
I have fallen for the SQL Studio issue too :) but isn't the maximum length of varchar 8,000 bytes, or 4,000 for nvarchar (unicode).
Any chance the column data type is actually text or ntext and you're converting to varchar?