Let's say I have a table that has a column of XML type data. Within SQL, I can execute the following statement:
select top 10 *,
Content.value('(/root/item/value)[1]', 'float') as Value
from xmltabletest
where Content.value('(/root/item/MessageType)[1]', 'int') = 1
The result set contains only the records matching the criteria, and it extracts a value from the XML into a column called 'Value'. Nice and simple.
Can the same thing be achieved with Linq To SQL?
I'd like to get SQL to do the heavy lifting and only return data matching my criteria rather than having to select, transfer, and then process a potentially massive chunk of data. As far as I can tell this isn't possible at the moment, but I thought I should ask.
(The environment is .NET 3.5, VS2008, SQL Server 2005 if that helps)
I'm not exactly sure if this is out of date now, but according to Scott Guthrie XML datatypes are:
represented as strings in LINQ to SQL
Entities. You could use XLINQ to query
on an XML column within your LINQ to
SQL entitiy - but this querying would
happen in your middle-tier (within
ASP.NET). You can't execute a remote
XQuery against the database and filter
returned results based on that in the
first release.
So in answer to your question, I'd say "no."
Related
I have a very simple DAX query which I can execute via SSMS with no problems.
As show above, the query returns 2 rows, one from the dynamic expression and one hardcoded "123".
When executed via C# Microsoft.AnalysisServices.AdomdClient, the hardcoded "123" row value is returned (oddly the ordinal position of rows does not match the execution in SSMS), but the dynamic expression row value is always null. This issue does seem to be isolated to the tables of this model as querying brand new "AdventureWorks" model programmatically does return values for dynamic expressions as well.
I am at a loss of what to explore next and I don't have high familiarity with querying Analysis Services programmatically, so any help would or hints what to try would be much appreciated.
I need to search an oracle table column for multiple word strings in cognos oracle query.
For example:
If Focus parameter returns multiple values as below
TRAINING
OMNIA
COUNTER
PROGRAM
And I need to search project.proj_name column like '%TRAINING%' or '%OMNIA%' or '%COUNTER%' or '%PROGRAM%'
I am trying below but I know it does only single value match not multiple. I want to know how to achieve multiple value match here.
'-99' in (#promptmany('Focus', 'string','-99')#) OR REGEXP_LIKE(proj_name, #promptmany('Focus', 'string','-99')#))
Working from Cognos Paul's solution to use output from promptmany as a table:
Assuming your query is named Q1...
Add a query. (Q2)
Add a SQL object to that query.
Set the Data source property for the SQL object.
Change the SQL Syntax property to IBM Cognos.
Define the query as
SELECT
parameterValue
FROM (VALUES
(#join('),(',split(',',promptmany('Scenarios','string',sq('N/A'))))#)
) query(parameterValue)
(change the names for your own use case)
Add a query. (Q3)
Add a join to the new query.
Add Q1 and Q2 to the empty boxes for the join leading to Q3.
Set the join as
[Q1].[proj_name] like '%' || [Q2].[parameterValue] || '%'
Add the required data items to Q3.
Since two keywords (from your parameter -> Q2) could be found in a single value (in Q1), you'll likely end up with duplicate rows. Cognos will probably handle this with its default aggregations, but keep a lookout.
Be careful with this. The new query (Q2) will probably be joined on the Cognos server, not on the database server. Be sure you have sufficient filters leading into this structure so Cognos is not trying to process your entire database.
This worked for me with SQL Server. I don't have an Oracle database to test against, but using IBM Cognos as the SQL Syntax should handle that.
To use REGEXP_LIKE to solve this problem, you'll need to get the second argument correct. I can't see any reason to see the error message ORA-00996: the concatenate operator is ||, not |, but I'm not working with your code in your system.
You don't specify which version of Cognos, or even which Cognos product, you are using. I'll assume Cognos Analytics 11.1.7.
To determine what Cognos Analytics is doing with your macro, create a very simple query with one item from the database (preferably from a very small table) and another data item that contains the macro. So the data item expression is:
#sq(join('|',split(',',promptmany('Focus','string','-99'))))#
When you run this, you may not be prompted. You'll see the value is -99. So to test this we'll need to remove the default so that the prompt becomes required.
#sq(join('|',split(',',promptmany('Focus','string'))))#
Be sure to enter more than one value when you test.
In my environment, the parameter returns a value that is my values surrounded by quotes (') and delimited by semicolons (;). So my tests produced the following:
expression
value
#sq(promptmany('Focus','string'))#
'PROGRAM';'COUNTER';'TRAINING'
#sq(join('|',split(',',promptmany('Focus','string'))))#
'PROGRAM';'COUNTER';'TRAINING'
#sq(join('|',split(';',promptmany('Focus','string'))))#
'PROGRAM'|'COUNTER'|'TRAINING'
replace(#sq(join('|',split(';',promptmany('Focus','string'))))#, '''', '')
PROGRAM|COUNTER|TRAINING
Your mileage may vary.
At this point, you know which macro to use in the REGEXP_LIKE function.
I need to support legacy client and compose ADO datasets from our Linq queries. The problem is how get specific column information (varchar length, decimal precision, etc) that cannot be obtained using reflection.
for example, I have table Customer with field Name varchar(80)
When I fetch data from linq to entities query:
var data = (from c in ctx.Customers select c.Name).ToList()
I cannot obtain maxSize for the column data[i].Name and adodataset raises an error.
I already have simple solution:
Code to extract column metadata from ObjectContext by property reference
Simple code that parses expression from Queryable and links output properties to edm columns.
But I have a lot of issues parsing complex queries that include multiple nested groupbys/unions/joins etc.
Does anybody know any other way (maybe using materialization shaper or similar)?
Thanks to EFProviderWrappers by Joseph Kowalski I have made similar provider and published it on codeplex
i'm trying to write an Oracle query that sorts the results in the same way as MS SQL Server does. I'm toying with the 'NLSSORT' function and it's parameters but i can't get exactly the same results as what i can see with MS SQL Server.
The context is a generic data collection system that supports both Oracle and MS SQL Server. This is a pretty old system that is still under maintenance and development. No entity framework or any recent approaches to handle database interactions.
With a simple order by on MS SQL Server i get this result:
_TEST
04-00031-IPE
04-00044-OG
0A-A
A0-A
SAZ2217
The same query on Oracle returns this:
04-00031-IPE
04-00044-OG
0A-A
A0-A
SAZ2217
_TEST
I have tried many combinations of NLSSORT parameters without any success.
[edit]
By using the 'PUNCTUATION' NLS_SORT parameter value, i get results very close to the MS SQL sorting but there is still differences with substrings that contains sequences of numeric chars. Here is a sample query result:
Oracle
0031-CASTOR-BLOC1-AV-AP
0031-CASTOR-BLOC1-AV-SP
0031-CASTOR-BLOC1-SV-AP
0031-CASTOR-BLOC1-SV-SP
0031-CASTOR-BLOC10-DV-AP
0031-CASTOR-BLOC10-DV-SP
0031-CASTOR-BLOC2-DV-AP
Ms SQL
0031-CASTOR-BLOC10-DV-AP
0031-CASTOR-BLOC10-DV-SP
0031-CASTOR-BLOC1-AV-AP
0031-CASTOR-BLOC1-AV-SP
0031-CASTOR-BLOC1-SV-AP
0031-CASTOR-BLOC1-SV-SP
0031-CASTOR-BLOC2-DV-AP
Thank you for your help!
I finally found this solution:
ORDER BY NLSSORT(COLUMN_NAME, 'NLS_SORT = FRENCH_M')
At least in my particular context, i get the same sorting under both MS SQL Server (default sorting) and Oracle.
Here is two useful links:
http://www.myoracleguide.com/xl/Linguistic_Sorting_Frequently_Asked_Questions.htm
http://download.oracle.com/docs/cd/B19306_01/server.102/b14225/ch5lingsort.htm#NLSPG005
Could consider use of rpad function?
e.g.
select name, rpad(upper(replace(translate(name,'_','+'),'-','') ),15,'0') as v1
from sorttest order by
rpad(upper(replace(translate(name,'_','+'),'-','') ),15,'0')
I have an Oracle database with all the "data", and a Solr index where all this data is indexed. Ideally, I want to be able to run queries like this:
select * from data_table where id in ([solr query results for 'search string']);
However, one key issue arises:
Oracle WILL NOT allow more than 1000 items in the array of items in the "in" clause (BIG DEAL, as the list of objects I find is very often > 1000 and will usually be around the 50-200k items)
I have tried to work around this using a "split" function that will take a string of comma-separated values, and break them down into array items, but then I hit the 4000 char limit on the function parameter using SQL (PL/SQL is 32k chars, but it's still WAY too limiting for 80,000+ results in some cases)
I am also hitting performance issues using a WHERE IN (....), I am told that this causes a very slow query, even when the field referenced is an indexed field?
I've tried making recursive "OR"s for the 1000-item limit (aka: id in (1...1000 or (id in (1001....2000) or id in (2001....3000))) - and this works, but is very slow.
I am thinking that I should load the Solr Client JARs into Oracle, and write an Oracle Function in Java that will call solr and pipeline back the results as a list, so that I can do something like:
select * from data_table where id in (select * from table(runSolrQuery('my query text')));
This is proving quite hard, and I am not sure it's even possible.
Things that I can't do:
Store full data in Solr (security +
storage limits)
User Solr as
controller of pagination and ordering
(this is why I am fetching data from
the DB)
So I have to cook up a hybrid approach where Solr really act like the full-text search provider for Oracle. Help! Has anyone faced this?
Check this out:
http://demo.scotas.com/search-sqlconsole.php
This product seems to do exactly what you need.
cheers
I'm not a Solr expert, but I assume that you can get the Solr query results into a Java collection. Once you have that, you should be able to use that collection with JDBC. That avoids the limit of 1000 literal items because your IN list would be the result of a query, not a list of literal values.
Dominic Brooks has an example of using object collections with JDBC. You would do something like
Create a couple of types in Oracle
CREATE TYPE data_table_id_typ AS OBJECT (
id NUMBER
);
CREATE TYPE data_table_id_arr AS TABLE OF data_table_id_typ;
In Java, you can then create an appropriate STRUCT array, populate this array from Solr, and then bind it to the SQL statement
SELECT *
FROM data_table
WHERE id IN (SELECT * FROM TABLE( CAST (? AS data_table_id_arr)))
Instead of using a long BooleanQuery, you can use TermsFilter (works like RangeFilter, but the items doesn't have to be in sequence).
Like this (first fill your TermsFilter with terms):
TermsFilter termsFilter = new TermsFilter();
// Loop through terms and add them to filter
Term term = new Term("<field-name>", "<query>");
termsFilter.addTerm(term);
then search the index like this:
DocList parentsList = null;
parentsList = searcher.getDocList(new MatchAllDocsQuery(), searcher.convertFilter(termsFilter), null, 0, 1000);
Where searcher is SolrIndexSearcher (see java doc for more info on getDocList method):
http://lucene.apache.org/solr/api/org/apache/solr/search/SolrIndexSearcher.html
Two solutions come to mind.
First, look into using Oracle specific Java extensions to JDBC. They allow you to pass in an actual array/list as an argument. You may need to create a stored proc (it has a been a while since I had to do this), but if this is a focused use case, it shouldn't be overly burdensome.
Second, if you are still running into a boundary like 1000 object limits, consider using the "rows" setting when querying Solr and leveraging it's inherent pagination feature.
I've used this bulk fetching method with stored procs to fetch large quantities of data which needed to be put into Solr. Involve your DBA. If you have a good one, and use the Oracle specific extensions, I think you should attain very reasonable performance.