Query a Query

I have a result set in a query.
Is it possible to query this query?

(no specific SQL dialect, can it be done generically?)

Petros

--
0
PETROS
1/20/2010 5:33:35 PM
embarcadero.delphi.database 1294 articles. 0 followers. Follow

2 Replies
1379 Views

Similar Articles

[PageSpeed] 37

PETROS GAVRIELIDES wrote:
> I have a result set in a query.
> Is it possible to query this query?
> 
> (no specific SQL dialect, can it be done generically?)

There is a generic answer to your question: Yes, there is a construct 
called a sub-query that allows you, in 1 SQL statement, to query from a 
query.

But, generically speaking, not all DB engines support this construct. 
For instance, Firebird only added it just over a year ago.

Loren sZendre
0
Loren
1/20/2010 5:47:12 PM
PETROS GAVRIELIDES wrote:

> I have a result set in a query.
> Is it possible to query this query?
> 
> (no specific SQL dialect, can it be done generically?)

The general syntax is 

  SELECT <fieldlist> FROM
     (SELECT <anotherfieldlist> FROM <tables, joins> WHERE <conditions>)
  WHERE <more conditions>

That is: you use the result set of one query as source for the next.
The columns in <anotherfieldlist> should have alias names, which you
can then use in the outer <fieldlist>. Not every database will support
that, even though it is part of the current ANSI SQL standard, as far
as I know.

-- 
Peter Below (TeamB)  
Don't be a vampire (http://slash7.com/pages/vampires), 
use the newsgroup archives :
http://codenewsfast.com
http://groups.google.com
0
Peter
1/20/2010 6:30:55 PM
Reply:

Similar Artilces:

How to Query A Query
I have been trying to build a crosstab report that reports everydate within a selected range across the top and specific row information. 7/1 7/2 7/3 . . . Name Detail1 Detail2 Detail3 Name Detail1 What I get as output is only the dates that contain information in the rows. I can get the information I need by using a query within a query (nested). Can a nested query be done in Informaker 5? What about version 6 or 7? Thanks for your help Convert your SQL to syntax, and you can write anything you want. So if your DB support...

How to query a query...
I'm working on converting an Access DB that I created into an ASP.NET application (and attempting to learn ASP at the same time...). One of my queries was very complex and required running a different query first, and then working off of that one. Any suggestions on the best way to do this in ASP? The following is a sample of code I'm using so you can see the type of data-binding I'm using. Thanks for the help! myConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; " +"Data Source=" + Server.MapPath("/EquipmentCheckout.mdb")) strS...

Query about Queries
Hello all, As a relatively new user to Sybase I am hoping someone can point me in the right direction. We are getting ready to go live with our database and I am wondering what types of queries I should be running for system performance purposes. If anyone has any suggestions they would be more than appreciated. Thanks in advance, Jerry ...

LDAP queries linked to SQL database queries
Hi, I am wondering whether it is common practice to use the AD domain users information as a link table for user information in database queries. My first thought is that it would be too slow since it can potentially query the AD many times depending on the number of records returned. Any insight is appreciated, sivilianMy Weblogs...

Querying a Queried result...
Hi, is there such a thing as querying a queried result? Example, query 1 produces Result A. Result A's table is stored 'somewhere' to be queried by query 2 which produces Result B If there is, could you kindly direct me to a website with the appropiate article on this topic? Thanks, -Gabian- Yes there is, querying a View is querying a query rewrite. Send me an email the address is in my profile I will send you a Views tutorial I wrote a while back and run a search for query results from View in your BOL(books online) for code samples. Hope this helps. Kind regards, ...

Query Plan Query
We have a sql query that is causing a few issues in terms of performance as the optimisor is choosing to table scan where an index will certainly yield significant gains. As proven when snapshotting the query and adding an index hint manually. Unfortunatley since the query is dynamically created by a 3rd party application, we are unable to influence this with index hints and are dependant on the optimiser. The table that is table scanning is partitioned (has also hust been repartitioned to address a slight inbalance across partitions) and has 7.6M records. It has been recently r...

Exacute query against query
I have a query which selects all dates from my database between 2 date values which is then entered into my dataset. I thin want to run through the dataset totalling the value of a certain column but only if dates match e.g. 27/02/2007          2.21 27/02/2007          3.10 27/02/2007          2.10                           Tota...

query runs fine in Query Analyser but not the Query Debugger
I'm running a query, actually its an insert that works when using the TSQL below. However when I try to use the debugger to step through and using the exact same values as those below I get the following error: [Microsoft][ODBC SQL Server Driver]Invalid character value for cast specification Its Killing me because everything else works, but this. Can somebody help. DECLARE @NoteID INT,-- NULL OUTPUT, @Note_Description NVARCHAR(3000),-- = NULL, @Date DateTime,-- = NULL OUTPUT, @ByWho NVARCHAR(30),-- = NULL, @FK_Action_Performed NVARCHAR(40),...

SQLite query and AS in query
This is my code. {code} q := TSQLQuery.Create(nil); try q.SQLConnection := MainForm.sqlite1; q.SQL.Text := sql; q.Open; finally q.Free; end; {code} And this is my SQL select id as _id, name, note as description from notes q.Fields[0].FieldName is id, it should be _id q.Fields[2].FieldName is note, it should be description Is this normal or am I missing something Grega This is frustrating. I can't work at all. http://pretty-software.com/images/xe4.jpg Edited by: grega loboda on Jun 4, 2013 1:40 AM http://stackoverflow.com/question...

Having trouble querying a query?
I'm trying to transition my reports from Access 2000 into Infomaker 7.0 but I'm having trouble combining two queries together. In Access you had to option of pulling tables or queries as your data, I don't see this option in Infomaker, am I missing something. Thanks from a newbie... IM doesn't have this feature, since it adheres to general Ansi SQL standards. If you show me the Access query, maybe I can give you a workaround. Are you querying an Access DB or a different DB, e.g. Oracle? -- Terry Dykstra (TeamSybase) Please state PB / OS / DB versions in your ...

Query to Save Queries
Save SQL Statements in the Host SQL MENU??? Hi there, I want to add items to the pencil menu in the Host SQL page. Eg. "Save SQL Query". Could someone point me in the right direction on how to populate the pencil menus. Thanks in advance. If your interested read on : So the idea is to make the currently "empty" pencil menu contain a list of queries, hosts/DnnCommunity can click on & execute, rather than typing them in each time. ''in the page load of admin/portal/sql.ascx.vb ln: 57 I want to add this line of code If Len(Request.Params(&quo...

Query a query in linq
Hi, I have some code that gets some results:var GlobalTable = from p as db.table                             select p; Now I want to run a query in link on the results stored in GlobalTable. Whats the best way to do this? keepin' it real in the ATX. Exactly the way you ran the first query: var GlobalTableSubset = from gt as GlobalTable                        ...

Query of Queried data
I am new to asp.net after working with coldfusion.  I have created a datagrid from a query of a sql database.  I am interested to know how can I create another datagrid which will process a query of the data in the original grid.  So essentually it is a query of a query. Thank you   You want to filter on the result of the first query? The easiest way I can think of, is to put the data in a datatable, then use the select and dataview features of the datatable. Hi,uusquintsYou can filter the datatable in the code-behind and bind the result to the 2nd datagird:...

Query and Sub-Queries
I have a SELECT statement that has two sub queries in it. The 'where' clause in the main query filters a TRADE_DATE field, for example: ...... where TRADE_DT >= '2003/01/01' and TRADE_DT <= '2003/01/31'. Since I only have one date field(TRADE_DATE), I want the sub-query to query where TRADE_DT <= '2003/01/31'. But its not working. I have to hard code the '2003/01/31'. Now I know I can make a dynamic view in VB, but an ideas of how I can do it in SQL? Here's my statement: select T.BROKER_SEQ_NO,B.BROKER_NAME,B.B...

Web resources about - Query a Query - embarcadero.delphi.database

Query - Wikipedia, the free encyclopedia
Text is available under the Creative Commons Attribution-ShareAlike License ;additional terms may apply. By using this site, you agree to the ...

Qubole Debuts Presto-As-A-Service, Based On Facebook-Created Open-Source Interactive Query System
Facebook announced last November that it would open-source interactive query system Presto , and now cloud big data platform provider Qubole ...

faroo_p2p: FAROO Search: Spelling correction, Query completion and Instant search http://t.co/TgHECDe5 ...
faroo_p2p: FAROO Search: Spelling correction, Query completion and Instant search http://t.

Query Strings - Quora
Quora is your best source for knowledge.

Google News Follow Query - Flickr - Photo Sharing!
searchengineland.com/google-news-adds-follow-news-query-5...

Legal query raised over super trawler
Legal query raised over super trawler

Passenger 'absolutely humiliated' by Jetstar pregnancy query
Passenger 'absolutely humiliated' by Jetstar pregnancy query

Sydney siege: Urgent query after bailed gunman 'slipped through the cracks'
He had a long history of violent crime and mental instability. So why on earth was he free on bail?

'Pies query Cloke frees after AFL loss
Collingwood coach Nathan Buckley stresses Travis Cloke's lopsided free-kick count was not the No.1 issue after they lost to Richmond by five ...

Perth family query 'fair go' of deportation
A Sorrento family being deported back to the UK on Friday over a visa wrangle believes that immigration bureaucrats have not lived up to the ...

Resources last updated: 1/22/2016 7:09:32 AM