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Forum:
WinDev Forum
Beiträge im Thema:
4
Erster Beitrag:
vor 4 Jahren, 9 Monaten
Letzter Beitrag:
vor 4 Jahren, 9 Monaten
Beteiligte Autoren:
Jose Antonio Garrido, Arnaud Benhamdine, Fabrice Harari

[WD18][Solved] New feature 124: "explain" function, sounds interesting, but doesn't exist.

Startbeitrag von Jose Antonio Garrido am 19.07.2013 15:58

Hi.

This is what it says in the booklet:
-An SQL query can involve a lot of task, read, filter,sort,union (...)
-HyperFileSQL optimies the order in which this actions are performed (...)
-The Explain function provides the details of a query's execution plan.

But thgere is no reference on how to use the "explain" function in the online help.
And If you write the name of the funcion in the code editor, it generates a compilation error (function does not exist)

Best Regards,
José Antonio.

Antworten:

Re: [WD18] New feature 124: "explain" function, sounds interesting, but doesn't exist.

Hi José Antonio

"explain" is not a wlanguage function, it's a SQL function...
Which means that you can use it by example in the HF Control center, SQL tab, where you can write (or paste) a query...

Pasting a regular query will give you its result that you can inspect...
Adding EXPLAIN in front of the regular query will give you information about how it works...

By example, a result returned by the xplain function on one of my queries is:






sSiteCode
sLanguageCode
IDMenu
dtDateTime
IDArticles



nestedloops
inner

ALIAS_35
( Articles.IDMenu = 17)



ALIAS_37
( Menu.IDMenu = Articles.IDMenu )








As to the exact content of the answer, I coul'nt find anything in the pcosft help files but I'm pretty sure you can find explanation about the EXPLAIN command in SQL web sites. Of course, as each DB is implementing things just a little differently, you may have to jump here and there

Best regards

von Fabrice Harari - am 19.07.2013 17:22

Re: [WD18] New feature 124: "explain" function, sounds interesting, but doesn't exist.

Hi,

In the French LST n°92, you can find a sample ("Exemple Explain TDF18") which allows to use the EXPLAIN command and also draws a visual representation of the execution plan of the query.
Very handy.

Yes, of course, it's in French... but actually it's not a problem.

Cdlt, Arnaud.

von Arnaud Benhamdine - am 19.07.2013 20:47

Re: [WD18] New feature 124: "explain" function, sounds interesting, but doesn't exist.

Well, Fabrice i'm very very grateful.

You not only cleaered up my question, but you went further, and I just learned two or three useful things!

Thanks to Arnaud too.

Best Regards,
José Antonio.

von Jose Antonio Garrido - am 19.07.2013 21:33
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