UpWhereChanged and ProviderFlags=[pfInWhere]
lazarus / 16-Databases

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Ign_17 · 2017-08-01 08:07

Hi everybody,

I´m a bit confused about the property "Upda]"]>Blockedde =
UpWhereChanged" and the "pfInWhere" value in ProviderFlags property.
As i´ve unsderstood, just especyfing "UpWhereChanged", automatically
the fields to modify on a update operation are included in the WHERE
clause of a UPDATE command.

On the other hand, Providerflags=[pfInWhere] specify whether a
specific field is incluyed or not in the WHERE clause of an UPDATE
command. 
It seems both options plays the same or a similar role, specifying
what fields will appear in the Where clause of an update operation.

Please, can anyone explain me what is the difference, and how these
two properties ( UpWhereChnged and TproviderFlags.pfInWhere) are
related one with the other?

Thanks in advance

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LacaK · 2017-08-01 13:09

upWhereChanged is specified at TSQLQuery level. It says, that
TSQLQuery updates should be constructed into SQL where WHERE part
consists of fields, which are locally changed + always fields which
are part of primary key.

pfInWhere is specified at TField level. So this give you additional
possibility include/exclude individual fields.

So if field is part of primary key then it is always also part of SQL
WHERE clause.
Next if Upda]"]>Blockedde=upWhereChanged AND field is changed then if
Fields ProviderFlag has pfInWhere (default) then this field is added
to where clause in other cases is not added.

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Ign_17 · 2017-08-01 17:53

Perfectly clear,
thank you very much for your explanation.

Regards,