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23/08/2006 10:12:06
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Forum:
Visual FoxPro
Catégorie:
Autre
Divers
Thread ID:
01147803
Message ID:
01147902
Vues:
38
My mistake, it was Martin J who indicate no to #4, but my point is still valid.

>If you re-erad my message, you will see that I am only commenting, not arguing.
>
>>Then you are talking about fixing his program, but he is asking about converting it to run under VFP9. I agree the new syntax is better and more precise, but this will not break anything that is not already broken and will give him access to a better IDE, better data integrity, and other performance and stability enhancements that VFP9 offers.
>>
>>Whats the downside? After he has the app up and running, if he and his client feels it is necessary to enhance the product, rewriting the SQL's would be a good place to start.
>>
>>>No, that's not what I try to say. I am saying that VFP6 may under some conditions give wrong results because it accepts syntax which is not ANSI-SQL compliant. This was considered a serious bug, and was fixed in VFP8 and even more in VFP9. However, in order to help us developers, the SET ENGINEBEHAVIOR was introduced as a "band aid" to cure the bleeding, but not to heal, so to say. With SET ENGINEBEHAVIOR 70 in VFP8 and VFP9 you will get exactly the same result as in VFP6, but this result may be the wrong result.
>>>
>>>>Are you saying VFP9 using the old style syntax will produce a different result than in VFP6, I have never seen this.
>>>>
>>>>>Well, if you really want to sit on an armed bomb, be my guest! :-))
>>>>>
>>>>>>I don't agree in this case, he is converting an existing application which already uses the less desireable SQL syntax, but I don't think his application will produce different results than he already has in the old app.
>>>>>>
>>>>>>If he chooses to refactor his application, then he should look at converting the SQL statements to the current standards, but if he porting an existing working application to the new platform, the solution is reasonable.
>>>>>>
>>>>>>>>>IMHO, 4 Yes
>>>>>>>>>
>>>>>>>>>MartinJ
>>>>>>>>>
>>>>>>>>>>Sorry for the short answers
>>>>>>>>>>
>>>>>>>>>>1 Yes
>>>>>>>>>>2 No
>>>>>>>>>>3 Yes (no additional fees to MS)
>>>>>>>>>>4 No
>>>>>>>>>>5 Yes
>>>>>>>>>>
>>>>>>>>>>Good luck!
>>>>>>>>
>>>>>>>>With just one line of code you make VFP9 almost totally compatible with VFP6:
>>>>>>>>SET ENGINEBEHAVIOR 70
>>>>>>>
>>>>>>>SET ENGINEBEHAVIOR 70 should be renamed to SET WRONG RESULT ON!
>>>>>>>
>>>>>>>There was a very good reason why the engine behavior was changed in VFP8 and VFP9. The SET ENGINEBEHAVIOR command was introduced as a short time band aid, so that the wrong, not ANSI-SQL compliant SQL statements which were accepted in VFP6, did not raise errors. However, if you don't correct the SQL statements and change SET ENGINEBEHAVIOR to 80 or 90, you risk getting wrong results.
'If the people lead, the leaders will follow'
'War does not determine who is RIGHT, just who is LEFT'
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