Stored procedure explanation

  • Hi all,

    this is the first time am working on stored procedures, I need to make changes to the existing SP and to use new altered SP in my reports.

    Can anybody explain the follwing SP, then I may able to make changes to that and use.

    How can I go with this SP's while creating or modifying.

    please help me

    Create PROCEDURE [dbo].[getNotificateProduct]

    @search as varchar(1000),

    @store as varchar(50),

    @lan as varchar(2)

    AS

    BEGIN

    Declare @haku varchar(50)

    declare @temp as table (ParameterCaption varchar(100), ParameterValue varchar(100))

    IF substring(@search, LEN(@search),1)<>';'

    SET @search = @search + ';'

    while CHARINDEX(';',@search)>0

    BEGIN

    SET @haku=UPPER(LTRIM(cast(substring(@search,0, charindex(';',@search)) as varchar(50))))

    INSERT INTO @temp

    SELECT CASE

    WHEN @lan ='FI' THEN

    [Material_FI]

    WHEN @lan ='EN' THEN

    [Material_EN]

    END AS ParameterCaption,

    '[Material DIM].[Material FI].&['+ CAst([DimCubeProduct].[ProductKey] as varchar(50))+ ']' AS ParameterValue

    FROM [DimCubeProduct] INNER JOIN

    FactStoreQualityNotification ON [DimCubeProduct].[ProductKey] = FactStoreQualityNotification.[ProductKey] AND

    Charindex(Cast(FactStoreQualityNotification.StoreKey as varchar(5)),@store)>0

    WHERE (@haku = '') OR

    (

    (@lan='FI' AND CHARINDEX(@haku, UPPER([Material_FI])) > 0)

    OR

    (@lan='EN' AND CHARINDEX(@haku, UPPER([Material_EN])) > 0)

    )

    ORDER BY [ProductID]

    SET @search = substring(@search, charindex(';',@search)+1, LEN(@search) - 0)

    end

    SELECT DISTINCT * FROM @temp

    END

    GO

    Thanks,

    Niha

  • It would appear that a table variable is being populated based on a While Loop. The While Loop is based on the comma separated values that come in the @Search variable. The @Haku variable contains the "element" of the @Search string that is currently being worked on.

    Personally, I'd split the @Search string using a decent non-looping splitter and do the whole stored rocedure as a single, set-based query (single query does not always constitute set-based).

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • niha.736 (1/27/2013)


    How can I go with this SP's while creating or modifying.

    if exists (select 1 from sysobjects where name = 'getNotificateProduct')

    DROP PROCEDURE [dbo].[getNotificateProduct]

    GO

    Create PROCEDURE [dbo].[getNotificateProduct]

    (

    )

    begin

    ....

    ....

    end

    IS this what your are asking ?

    -------Bhuvnesh----------
    I work only to learn Sql Server...though my company pays me for getting their stuff done;-)

  • Bhuvnesh (1/28/2013)


    niha.736 (1/27/2013)


    How can I go with this SP's while creating or modifying.

    if exists (select 1 from sysobjects where name = 'getNotificateProduct')

    DROP PROCEDURE [dbo].[getNotificateProduct]

    GO

    Create PROCEDURE [dbo].[getNotificateProduct]

    (

    )

    begin

    ....

    ....

    end

    IS this what your are asking ?

    ALTER PROCEDURE [dbo].[getNotificateProduct]

    ...

    will replace the text of the existing procedure with the next text you specify.

    DROP will also drop all permissions and other things related to the proc (extended properties, etc.). That may not be a good idea in your environment.

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

  • I added some comments to your proc, and fixed the layout, formatting, capitalization - all of which was horrifying to begin with. Pick a coding standard and then use it. I don't care what you pick, but use it consistently. I've shown you the "capitalize all keywords" coding style, which I personally hate, but I'm making the point that if it's consistent, even if you hate that style, it's more readable. Also, be careful about your tabs and what you put on each line. DON'T use things you don't need, like the BEGIN and END for the proc itself - completely unneeded and doing nothing but cluttering up the screen. Anyway, the comments explain how the procedure works. This is not a very complicated proc, but the horrible style was making it very hard to read.

    CREATE PROCEDURE dbo.getNotificateProduct

    @search VARCHAR(1000), -- multi-values ('value1;value2;value3;')

    @store VARCHAR(50),

    @lan VARCHAR(2) -- only 'FI' and 'EN' are valid here

    AS

    DECLARE @haku VARCHAR(50) --loop variable to hold single values from @search

    -- table for building result set

    DECLARE @temp TABLE (ParameterCaption VARCHAR(100), ParameterValue VARCHAR(100))

    --if the incoming string doesn't end with a ; then add one

    IF SUBSTRING(@search, LEN(@search),1)<>';'

    SET @search = @search + ';'

    --initialize the loop control variable - this is a "chopping" loop,

    --where each iteration consumes a portion of the string and you continue

    --until there's no more string to consume (when a semicolon can not be found)

    --this is not written in the normal way - it would be better to update a position

    --variable, than to continuously update the value of a potentially really long string

    WHILE CHARINDEX(';',@search)>0 BEGIN

    --grab everything from the beginning of the string to the first semicolon,

    --removing leading spaces and converting to upper-case. This is the search string.

    SET @haku = UPPER(LTRIM(CAST(SUBSTRING(@search,0, CHARINDEX(';',@search)) AS VARCHAR(50))))

    --load rows into the temp table for the current search string,

    --using the proper column for the language - two separate queries would actually be faster here

    INSERT INTO @temp

    SELECT CASE

    WHEN @lan ='FI' THEN Material_FI

    WHEN @lan ='EN' THEN Material_EN

    END AS ParameterCaption,

    '[Material DIM].[Material FI].&['+ CAST([DimCubeProduct].[ProductKey] AS VARCHAR(50))+ ']' AS ParameterValue

    FROM DimCubeProduct --this is your main table

    INNER JOIN FactStoreQualityNotification --this is your join (right) table

    ON DimCubeProduct.ProductKey = FactStoreQualityNotification.ProductKey -- a JOIN condition

    AND CHARINDEX(CAST(FactStoreQualityNotification.StoreKey AS VARCHAR(5)),@store) > 0 -- another JOIN condition

    WHERE (@haku = '') OR -- where clause in the form of "A OR (B OR C)" - do you need the parens?

    ((@lan='FI' AND CHARINDEX(@haku, UPPER(Material_FI)) > 0)

    OR

    (@lan='EN' AND CHARINDEX(@haku, UPPER(Material_EN)) > 0))

    ORDER BY ProductID

    --chop off the 'front' of the string before we re-iterate - this is the "update the loop control variable" step

    SET @search = SUBSTRING(@search, CHARINDEX(';',@search)+1, LEN(@search) - 0)

    END

    SELECT DISTINCT * FROM @temp --wrong - you created the columns up at the top, you can't name them?! Don't use *

    --Also, if you loaded the correct data into the temp table you would gain performance by eliminating Distinct keyword

    For the inner portion of the loop, I would re-write that to have an "IF @lan='FI'" if-else block, and have a query for each language separately. For the 'FI' language, it would look like this...

    INSERT INTO @temp

    SELECT distinct Material_FI,

    '[Material DIM].[Material FI].&['+ CAST([DimCubeProduct].[ProductKey] AS VARCHAR(50))+ ']'

    FROM DimCubeProduct dcp --this is your main table

    INNER JOIN FactStoreQualityNotification fsqn --this is your join (right) table

    ON dcp.ProductKey = fsqn.ProductKey -- a JOIN condition

    AND CHARINDEX(CAST(fsqn.StoreKey AS VARCHAR(5)),@store) > 0 -- another JOIN condition

    WHERE (@haku = '')

    OR (CHARINDEX(@haku, UPPER(Material_FI)) > 0)

    ORDER BY ProductID

    This is a query which will be much easier to optimize. Since the old "CASE" portion caused different columns to be retrieved, covering indexes and other issues could cause the optimizer to pick a bad plan. With both queries separated, the optimizer can pick different plans for each one, and that should improve the performance overall. The old query isn't always bad, but it's bad more often than the new style I'm proposing. I used table aliases to make the join conditions easier to read.

  • You should probably thank me for that...

  • DON'T use things you don't need, like the BEGIN and END for the proc itself - completely unneeded and doing nothing but cluttering up the screen.

    Actually begin and end serve a VERY valid purpose within a proc. They very clearly define the beginning and the end. Yes it probably appears as a little overkill but it forces you to indent the code that is the body of the proc making it more clear in a large script what is what.

    _______________________________________________________________

    Need help? Help us help you.

    Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

    Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

    Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
    Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
    Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
    Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/

  • Sean Lange (2/11/2013)


    DON'T use things you don't need, like the BEGIN and END for the proc itself - completely unneeded and doing nothing but cluttering up the screen.

    Actually begin and end serve a VERY valid purpose within a proc. They very clearly define the beginning and the end. Yes it probably appears as a little overkill but it forces you to indent the code that is the body of the proc making it more clear in a large script what is what.

    That's FALSE. Since you can have an unlimited number of BEGIN/END combinations in a proc, they clearly don't define the beginning and the end of the proc, even if you want them to (and you can't prevent someone from later adding code before the first BEGIN or after the last END, which is reason enough to NEVER consider "BEGIN" and "END" as "defining the beginning/end of a proc").

    The block created by BEGIN/END adds restrictions on variable use, etc., outside that block, so you're just inviting errors with an unnecessary BEGIN/END.

    Furthermore, indenting unconditional code in a proc makes no sense and wastes space. The required:

    GO

    CREATE PROCEDURE

    within a script full of procs will inherently delineate the start and end of procs. Too many people over-indent as it is, making the code very hard to read.

    SQL DBA,SQL Server MVP(07, 08, 09) "It's a dog-eat-dog world, and I'm wearing Milk-Bone underwear." "Norm", on "Cheers". Also from "Cheers", from "Carla": "You need to know 3 things about Tortelli men: Tortelli men draw women like flies; Tortelli men treat women like flies; Tortelli men's brains are in their flies".

  • Sean Lange (2/11/2013)


    DON'T use things you don't need, like the BEGIN and END for the proc itself - completely unneeded and doing nothing but cluttering up the screen.

    Actually begin and end serve a VERY valid purpose within a proc. They very clearly define the beginning and the end. Yes it probably appears as a little overkill but it forces you to indent the code that is the body of the proc making it more clear in a large script what is what.

    BWAA-HAAA!!! That's precisely why I don't use it. I hate to be forced to do anything and I can't see burning the horizontal space by indenting virtually the whole proc by one tab.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Sean Lange (2/11/2013)


    DON'T use things you don't need, like the BEGIN and END for the proc itself - completely unneeded and doing nothing but cluttering up the screen.

    Actually begin and end serve a VERY valid purpose within a proc. They very clearly define the beginning and the end. Yes it probably appears as a little overkill but it forces you to indent the code that is the body of the proc making it more clear in a large script what is what.

    I find no reason to indent the first level of a proc. All that does is eat screen space.

Viewing 10 posts - 1 through 9 (of 9 total)

You must be logged in to reply to this topic. Login to reply