Error Handlicng when Table Doesn't Exists
lazarus / 16-Databases

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Weitentaaal · 2020-11-17 13:51

Hey Guys,

So i Got This Code:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i try   
 MacAd := dbHist.FieldByName('ProgID').AsString;except      on E :
EDatabaseError do begin           //ShowMessage('DB ERROR:' + ' ' +
E.ClassName + ' ' + E.Message);          //If This Table (RollBK)
Doesnt Exists, then create it -->          //SQL := 'CREATE TABLE
ROLLBK (Td DATE, Tt TIME, Zeichnung INTEGER, Part INTEGER, Act
INTEGER, Pid TEXT(20));';      end;   end; 
Any1 any Idea how i Can do this ?

Thanks A Lot

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Zvoni · 2020-11-17 14:29

Huh?

https://www.freepascal.org/docs-
html/fcl/sqldb/tsqlconnection.gettablenames.html

Why not just look it up beforehand?

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Weitentaaal · 2020-11-18 09:31

i just searched for the Wrong Thing Sorry

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rvk · 2020-11-18 09:38

And besides that... you have the try/except around the wrong code.
That will only trigger the except if there is no FIELD ProgID.

If you use a table which doesn't exists (like stated in your title)
you need to put the sql.open (with SELECT) inside try/except. Then you
can examine the exception if it contains "table not found" or
something (depending on your database).

Checking beforehand with gettablenames would indeed be preferable over
exceptionhandling.

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Weitentaaal · 2020-11-25 09:26

Thanks rvk

Understand this whole thing better now.
I went with the gettablenames