Subject Re: R: [IBO] Error filtering TIBO* on boolean Fields
Author Helen Borrie (TeamIBO)
At 06:27 PM 18-02-02 +0100, you wrote:
>This is right i use an IBO emulation of Boolean field but, if i have
>understand, this emulation don't work on Filter property.
>It's right ?
>I haven't any other way ?

The emulation is to make the *client* handle the field as a Boolean. The database itself does not support a Boolean.

A filter for IB/FB is achieved by the SQL parser applying an extra (or substitute) subclause in your WHERE clause, and it has to parse as correct SQL. As your filter has to work in an SQL statement, it must query the database on the data actually stored. Hence the form of the Filter property must be 'YourBooleanField='T' ' or 'YourBooleanField=1', according to what you define in the db.
>
> But i have a visual component (very user friendly) on my form who write
>the filter property form me (and for my client) and this component don't like
>an expression of this type:

A few desktop databases (e.g. Paradox) do support a native Boolean type so a component like this would be friendly for use with them. I would be cautious about using this component with IB because you are probably going to hit other bugs, e.g. with regard to NULL columns. Paradox doesn't recognise NULL and stores zero-equivalents instead.

If you have the source, perhaps you could write a descendant of that component that overrides the assumptions the existing component makes about the database...


regards,
Helen Borrie (TeamIBO Support)

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