Does It Matter If The Criteria Is In The FROM Or The WHERE?
May 6, 2008
I have a query that searches through a 4 million record table. The data is fed from the UNIX flat file systems so the data is not in optimal search format. So I created some views that massaged the data and then index them. I select and join the original table with the view, with NOEXPAND hint on the view. My question is this theory right: If I put the criteria in the FROM join part then it will make the join easier than if I put it in the where clause?
Example (any difference)
SELECT stuff1, stuff2 FROM UglyData u INNER JOIN MassageTable m ON m.RecNumber LIKE '112%' AND u.ID = m.ID
versus
SELECT stuff1, stuff2 FROM UglyData u INNER JOIN MassageTable m ON u.ID = m.ID WHERE m.RecNumber LIKE '112%'
SELECT * FROM TableA A JOIN TableB B ON A.PrimaryKeyID = B.ForeignKeyID WHERE B.SomeParamColumn = @SomeParam
SELECT * FROM TableA A JOIN TableB B ON A.PrimaryKeyID = B.ForeignKeyID AND B.SomeParamColumn = @SomeParam
Both of these queries return the same result set, but the first query filters the results in the WHERE clause whereas the the second query filters the results in the JOIN criteria. Once upon a time a DBA told me that I should always use the syntax of the first query (WHERE clause). Is there any truth to this, and if so, why?
I'm setting up SQL Server 7.0 as follows: 12 Gb initial data load; heavy transaction OLTP; 4 processors; RAID5 disk space NOT an issue.
I'm trying to figure out what a reasonable initial size for both the Transaction Log and Tempdb should be. I was thinking 100Mb for each. Is this reasonable, or could either afford to have more?
Is there a percentage of the .mdf that is recognized as a general rule of thumb for setting up the Transaction Log and/or Tempdb?
Also, is there any value in assigning Filegroups in a RAID5 setup?
I've officially done everything. I've uninstalled everything I can think of. I've cleaned the registry until it sparkles. I've removed all directories having anything to do with VS or SQL. I've even run the uninstall tool multiple times and been told everything is OK. However, SQL Server Express STILL tells me there are "beta versions" of stuff on my machine. Do you have any suggestions, or should I just give up in disgust?!?!?!
Does column order really matter for Query Optimizer to pick index.Case 1: Say my CUSTOMER table has one composite index containing FirstName and LastName. FirstName exists prior than LastName. Does the column, FirstName and LastName, order matter to have Query Optimizer to utilize the index when I write WHERE clause in a SELECT statement?Statement 1:SELECT * FROM CUSTOMER WHERE FirstName = 'John' and LastName ='Smith'Statement 2:SELECT * FROM CUSTOMER WHERE LastName ='Smith' and FirstName = 'John' Will both statement 1 and 2 use the composite index or only statement 1?Case 2:Say my CUSTOMER has two single-column indexes. One index is on column FirstName. Another is on column LastName.For statement 1 and 2 above, which index will be picked by Query Optimizer or both? How does QO pick for index?I read couple book and some books say column order matter but some say no. Which one should I go with? I'm kind of confused.
I have a question i need to ask. Since i'm new to SQL Server, i did a bit of experiment with SQL Server 2005 Express. I made up a simple Access Database file and migrated it to SQL Server. it was success which is good. Now i have a real Access Database file which i built for my client. Since he uses the SQL Server 2000 service pack 4, i was wondering if the version would matter a lot.
There are two fieldsA1 nvarchar(30)A2 nvarchar(800)I know nvarchar field is alterable length, if I store a string mystring='abc' to A1 field or to A2 field, I think they use the same disk space, so I think it's always a good way to define a big length nvarchar field such as A3 nvarchar(4000) for any length string, becuase they always use the same disk space, is it right?
I have two tables that I am trying to join and both have similar columns with which I am trying to use. One is Date and the other is LOGdate. Date's format is "01/01/2000" BUT LOGdate's is "01/01/2000 12:41:00 PM/AM". Can I join these two tables?
Does column order matter when creating a table? For example, Should NOT NULL columns always come before NULL columns? Should most frequently used columns always be near the top? What about text, ntext and image data types? Should they always appear near the end of the column order?
I have two tables that I am trying to join and both have similar columns with which I am trying to use. One is Date and the other is LOGdate. Date's format is "01/01/2000" BUT LOGdate's is "01/01/2000 12:41:00 PM/AM". Can I join these two tables? If yes how do I get rid of the excess time on LOGdate.
select b.isin, a.market, a.ccy, a.stock_mkt, max(a.year) ,max(a.month), max(a.day) from market_table a inner join isin_table b on a.id = b.id where a.isin_closing_date=0 and a.market in ('XFFA', 'XFFA') and b.isin_type= 'I' and b.isin = 'DEX' group by b.isin, a.market, a.ccy, a.stock_mkt
what's needed is to get the earliest record all times, no mater the currency :
I would like to create a database that keeps track of our companies subject matter experts. I have roughed out some of the tables. I would appreciate any feedback on if this is the right approach and if there might be any issues when I start writting a front-end (probably VB 2005).
What makes this interesting (at least for me) is that a subject has an owner and at least 1 "expert", possibly up to 3. Here is what I am thinking for tables:
If I join Table1 to Table2 with a WHERE condition, isit the same if I would join Table2 to Table1 consideringthat the size of the tables are different.Let's assume Table2 is much bigger than Table1.I've never used MERGE, HASH JOINs etc, do any ofthese help in this scenario?Thank you
As I am creating the non-clustered indexes for the tables, I dont quite understand how dose it really matter to put the columns in the index key columns or put them into the included columns of the index?
I am really confused about that and I am looking forward to hearing from you and thank you very much again for your advices and help.
Sometimes we have some pretty serious CPU spikes and I would like to be able to pinpoint the exact issue. I have been able through the DMVs to associate a session with an operating system thread. That's great if I have a batch that's causing the problem with a non NULL sql_handle. However, how do I further narrow down what is going on with the background service broker tasks using the DMVs? Or am I just at the blind mercy of SQL Server at this point? What can I query to know what the heck is going on?
I have a table GO CREATE TABLE [dbo].[Speech] ( [SpeechId] [int] IDENTITY(1,1) NOT NULL CONSTRAINT PkSpeech_SpeechId PRIMARY KEY, [UniqueName] [varchar](52) NOT NULL, [NativeName] [nvarchar](52) NOT NULL, [Place] [nvarchar](52) NOT NULL, [Type] [smallint] NOT NULL, [LanguageId] [char](2) NOT NULL CONSTRAINT FkSpeech_LanguageId FOREIGN KEY (LanguageId) REFERENCES Language(LanguageId) ON UPDATE CASCADE ON DELETE CASCADE, [SpeakerId] [int] NOT NULL CONSTRAINT FkSpeech_SpeakerId FOREIGN KEY (SpeakerId) REFERENCES Speaker(SpeakerId) ON DELETE CASCADE, [IsFavorite] [bit] NOT NULL, [IsVisible] [bit] NOT NULL, [CreatedDate] [datetime] NOT NULL DEFAULT GETDATE(), [ModifiedDate] [datetime] NULL ) Now I want to search the Table Speech Sometimes by : SpeechIdSometimes by : SpeakerIdSometimes by : LanguageIdSometimes by : SpeechId And LanguageIdSometimes by : SpeakerId And LanguageId All can have conditions with IsVisible, IsFavorite and Type columns. for example I need all Speeches withany particular SpeakerId and LanguageIdwith IsVisible equals to trueand IsFvaorite No Matterand Type equals to Audio For these type of queries I think the solution is GO CREATE PROCEDURE [dbo].[sprocGetSpeech] @speechId int = NULL, @uniqueName varchar(52) = NULL, @nativeName nvarchar(52) = NULL, @place nvarchar(52) = NULL, @type smallint = NULL, @languageId char(2) = NULL, @speakerId int = NULL, @isFavorite bit = NULL, @isVisible bit = NULL AS SELECT SpeechId, UniqueName, NativeName, Place, Type, LanguageId, SpeakerId, IsFavorite, IsVisible, CreatedDate, ModifiedDate FROM Speech WHERE SpeechId = @speechId AND UniqueName = CASE WHEN @uniqueName IS NULL THEN [UniqueName] ELSE @uniqueName END AND NativeName = CASE WHEN @nativeName IS NULL THEN [NativeName] ELSE @NativeName END AND Place = CASE WHEN @place IS NULL THEN [Place] ELSE @place END AND Type = CASE WHEN @type IS NULL THEN [Type] ELSE @type END AND LanguageId = CASE WHEN @languageId IS NULL THEN [LanguageId] ELSE @languageId END AND SpeakerId = CASE WHEN @speakerId IS NULL THEN [SpeakerId] ELSE @speakerId END AND IsFavorite = CASE WHEN @isFavorite IS NULL THEN [IsFavorite] ELSE @isFavorite END AND IsVisible = CASE WHEN @isVisible IS NULL THEN [IsVisible] ELSE @isVisible END Can anyone tell me? Is it right way to do?Do you have any better solution?If my solution is better then Is there any performance loss with that query?
i.e i wanted to represent data by quarter and year and group by quarter and year for interest_payment column but for balance i need to pick up the value from the first reporting date in that quarter ,so as you can see q1-2004 has 10,15 and 20 but only 10 is accounted as that was the first reporting date in that quarter
I have my query working for interest payment but i am not sure how do i pickup the first reporting value for balance in a quarter
SELECT report_year as "@date",'Q'+CAST(report_quarter+1 as varchar(1)) as "@quarter", SUM(a.balance) as "@balance", SUM(a.interest_payment) as "@interest_payment" FROM (SELECT *, (reporting_date%100 - 1)/3 as report_quarter, reporting_date/100 as report_year FROM employee) a GROUP by report_year, report_quarter order by report_year, report_quarter
That would be just the rows 1 6 3 0 2 6 1 0 2 5 3 0
If I use this:
Select CustomerId,PartNum, shipped, QtyInOrder AS MaxOrderedNotShipped from (SELECT [CustomerID] ,[PartNum] ,[QtyInOrder] ,shipped , row_number() over (partition by [CustomerID], PartNum order by QtyInOrder desc) as recid from [SILK].[dbo].[MaxofGroup]) as f where recid =1
there is no restriction, so I get the shipped...If I alter the where clause to work only on not shipped, I get no records...as below
Select CustomerId,PartNum, shipped, QtyInOrder AS MaxOrderedNotShipped from (SELECT [CustomerID] ,[PartNum] ,[QtyInOrder] ,shipped , row_number() over (partition by [CustomerID], PartNum order by QtyInOrder desc) as recid from [SILK].[dbo].[MaxofGroup]) as f where recid =1 and shipped=0
While playing with SQL Server 2000 I found you can specify the selection criteria in either the FROM clause or the WHERE clause: e.g. select * from Table1 a inner join Table2 b ON a.key = b.key and a.field = 1
Is logically the same as: select * from Table1 a inner join Table2 b ON a.key = b.key where a.a = 1
jiang writes "Apologies in advance for my inexperience.
I have a SQL table to hold my product information: prods(prodnum(char(10), prodname(char20), quantity(int))
The values in prodname column are like: ABCDEF ADCDEF BCDEFG CDEFGH
For those products that sold out, I made a mark in the front of prodname, like *ABCDEF
Then in my query, I want to sort the product name in alphabetic order, in addition, I also want to put prodname start with * at the end of the result list, like:
ADCDEF BCDEFG CDEFGH *ABCDEF
I tried to use: select prodname from prods order by prodname
this query shows *ABCDEF is on the top of the result, then I tried:
select prodname from prods order by charindex('*', namecode)
this query does put *ABCDEF at the bottom, but other records are not in alphabetic order.
Could you please help me? Many many thanks! Jiang"
hi all... how do i write my where clause if i wanna search BETWEEN something to something, but at the same time, find ALL if user send nothing (''), NOT searching for '' column... and also find date if they send a date, and if they dont send date, do not consider date at all(find all at any dates).. is this possible to in one where clause without any IF statement... thanks..
WHERE d.Ownership LIKE '%' + @ClientID +'%' AND d.WhsID LIKE '%' + @WhsFrom + '%' AND d.CustomLotNo LIKE '%' + @CustomlotnoFrom+ '%' AND d.LocID BETWEEN @LocFrom AND @LocTo AND d.ItemID LIKE '%'+ @ItemFrom + '%' AND substring(d.LocID,1,1) LIKE '%' + @ZoneFrom AND d.RecvDate <= @Date
I am trying to filter data from columns and this is just not working. If I select all the criteria below and try to run it - I do not get any records returned.
WHERE (DropDt >= DATEADD(month, DATEDIFF(month, 0, GETDATE()) - 13, 0)) AND (DropDt <= DATEADD(month, DATEDIFF(month, 0, GETDATE()) - 1, 0)) and Type IN ('Employee', 'Refinance')
I am just learning SQL server 2005 and I am having trouble with the sql statement of my sqlcommand. I am just trying to query for any ticket that was open yesterday. I need this to run daily If I run the following it works SELECT Assigned_Group, Assigned_Technician, Date_Created From "Support Center Ticket" where "Date_Created" > '08/30/2007 00:00:00' and division = 'Northern'
however when I change it SELECT Assigned_Group, Assigned_Technician, Date_Created From "Support Center Ticket" where "Date_Created" > convert(varchar, getdate()-1, 101) + ' 00:00:00' and division = 'Northern'
SSIS package "Package_test.dtsx" starting.
Information: 0x4004300A at Data Flow Task, DTS.Pipeline: Validation phase is beginning.
Information: 0x40043006 at Data Flow Task, DTS.Pipeline: Prepare for Execute phase is beginning.
Information: 0x40043007 at Data Flow Task, DTS.Pipeline: Pre-Execute phase is beginning.
Error: 0xC0047062 at Data Flow Task, DataReader Source [46]: System.Data.Odbc.OdbcException: ERROR [420] Driver]Unexpected extra token: (
at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode)
at System.Data.Odbc.OdbcCommand.ExecuteReaderObject(CommandBehavior behavior, String method, Boolean needReader)
at System.Data.Odbc.OdbcCommand.ExecuteReader(CommandBehavior behavior)
at System.Data.Odbc.OdbcCommand.ExecuteDbDataReader(CommandBehavior behavior)
at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
at Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter.PreExecute()
at Microsoft.SqlServer.Dts.Pipeline.ManagedComponentHost.HostPreExecute(IDTSManagedComponentWrapper90 wrapper)
Error: 0xC004701A at Data Flow Task, DTS.Pipeline: component "DataReader Source" (46) failed the pre-execute phase and returned error code 0x80131937.
Information: 0x40043009 at Data Flow Task, DTS.Pipeline: Cleanup phase is beginning.
Information: 0x4004300B at Data Flow Task, DTS.Pipeline: "component "OLE DB Destination" (6856)" wrote 0 rows.
Task failed: Data Flow Task
Warning: 0x80019002 at Package_test: The Execution method succeeded, but the number of errors raised (2) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
I am creating a .aspx page that links with Miscrosoft SQL Server 2005 Express. It includes a GridView control that displays all the table data on the page. You can then select a record from the control (currently by clicking an image button to the left of each record- is there any way of selecting the record by clicking anywhere on the row? How would that be done?) and it displays the data in a detailsview control below where the data can be changed etc. The data is like a phonebook (Name, Telephone number, and some other misc fields) and the user should be able to search by either name or number to filter out the records shown in the gridview control. I have two textboxes for this, and I started with the name text box and it works fine. i.e. with one filterparameter and one filterexpression. So that if you just enter 'Da' it filters out the records displaying only those whose name starts with 'Da'. I have experimented but have found no way of including filter expressions to use the number as a search. I added the second filter parameter (under sqldatasource control so that: <FilterParameters> <asp:ControlParameter Name="DestinationName" ControlID="txtName" /><asp:ControlParameter Name="DestinationNumber" ControlID="txtNumber" /> </FilterParameters> But I don't know what to do for the FilterExpressions. currently I just have: FilterExpression="DestinationName LIKE '{0}%'" i have tried using "DestinationName LIKE '{0}%' OR DestinationNumber LIKE '{0}%'" but it requires that both text boxes have data entered.
What I want is something that allows the user to enter either a name or number or both (all or part of so don't need to enter in full name/number) and it filters out the records accordingly. I.e. if you enterd 'Dav' and '079' it would bring back all the records who had a name starting with Dav and a number starting with 079. However if you enterd just 079 then it should just bring back all records with numbers starting 079 whatever their associated name.
I have a text box that is used to submit stock symbols that are to be saved in a sql table. The symbols are to be separated by a space or a comma (I don't know which, yet). I want to retrieve the symbols later to be used in a query, but I don't know how to get the symbols in the proper string format for the query, eg
The symbols are stored in the tables as: A B C D The query string criteria would look like: IN('A', 'B', 'C', 'D')
The IN('A', 'B', 'C', 'D') citeria would be the values in the @Symbol variable in this SPROC
SELECT a_Name_Symbol.Symbol, a_Financials.Revenue FROM a_Financials INNER JOIN a_Name_Symbol ON a_Financials.Symbol = a_Name_Symbol.Symbol WHERE (a_Name_Symbol.Symbol @Symbol) ORDER BY a_Name_Symbol.Symbol
Is there a slick (ie easy) way to change the contents entered in the text box (A B C D) into IN('A', 'B', 'C', 'D') ?
I have a database with some over normalized tables in it. The best I can do with one query is get the file ID. In the second query I want to get all the file names, based on all the fileID's I got from the first query. How would I go about doing this?
