Lookupc() function "stuck"

[forskare]

Re: Lookupc() function "stuck"

you're telling it to use the value of the field "B_maxisnumber" from table B to lookup into table A.

We're not on the same page. With this expression:

Lookupc("C","A_Maxisnumber","A_maxisnumber","t_tableA","maxis_numb")

where is the reference to tableB?

[csda1]

Re: Lookupc() function "stuck"

Hi Kenn,

This is what I understand:

Key value = the value in the A_maxisnumber field of TableA. To get this value, one must use the field name which contains the sought after value.

No. With quote's around the key value, you are asking it to look up in the index of TableA for an index key with character value A-_-m-a-x-i-s-n-u-m-b-e-r, not he value it contain's. This is a value to be placed here, based upon the current table (TableB in your case) or other variables and values, not an expression. E.g. If you want to look up a price tax rate index in another table, you would use InvoiceTotal, not a quoted "InvoiceTotal" If you have a 5 line item list, it could be a value like

Item1Price+Item2Price+Item3Price+Item4Price+Item5Price

but not

"Item1Price+Item2Price+Item3Price+Item4Price+Item5Price"

which is just a bunch of letters I-t-e-m-1........

Lookup Expression = The field in TableA which contains the value which is A_maxisnumber.

This is an expression (which could just be a field name as you have) that Alpha would evaluate in the context of the lookup table's record pointed to by the key_value and indexname. e.g.

"trim(City)+', '+trim(State)+' '+zipcode"

It does not know about any variables in the current code, although they could be inserted into the expression as if they look like constants, such as

"name-'abcdef'+'"+textvariable+"'"

Lookup Table = The table which contains the field (A_maxisnumber) which contains the value to be obtained.

Correct.

Index = The index in the Lookup Table, TableA, which is based on the field, A_maxisnumber. The same index exists in TableB for the common field, A_maxisnumber.

No. This index name (must be a valid string, as in "indexname", or varindexname where varindexname's value is a character type with a value of "indexname") is for the Lookup Table specified, not the current table (which is irrelevant). The index expression of this index could be any valid index expression, e.g.

trim(Category)+";"+trim(ProductName).

That is what the key value should look like. So if I was using this index looking for a widget that was a Golden Fancy Widget, my key value would be "Widget;Golden Fancy Widget".

If I use the match type "C", It will find the 1st record matching the key value or larger. So a key value of "Widget;G" would find the 1st record whose index key was equal to or larger than "Widget;G"

Since this expression is in the field rules for the field A_maxisnumber in TableB, it should 'get' and 'set' the value. The common linking field is a_maxisnumber. Is it possible one cannot do this with the common field itself?

Think about what value(s) in TableB's current record has a value that identifies a specific record in table A. The key value calculated from TableB's current record values is what determines what record you are accessing in TableA's index key, and thus what value's it's lookup expression returns.

[forskare]

Re: Lookupc() function "stuck"

Hi Ira,

Thank you for your detailed explanation. It certainly changes my perspective on this. I'll be able to study it further this evening and hopefully, it will light the bulb a bit brighter.

Thanks again,

ken

[forskare]

Re: Lookupc() function "stuck"

Well, this is interesting. The expression builder allows me to press the down arrow to select the First, Last or closest as well as the Lookup table and the Index. It tells me to press the down arrow or right click for the Lookup expression but that does not work. There is no opportunity to press the down arrow for the Key Value.

A5 automatically inserts the " " when a choice is made using the down arrow or right click. The expression builder will not accept the expression unless I put " " around both the Key Value or the Lookup Expression. So, there is no choice. It's either the expression builders' way or no way.

Maybe someone else can try this function and see if the 'down arrow' works where its supposed to work and if the expression can be saved w/o the " around the Kwy Value.

Thanks,

kenn

[Al Buchholz]

Re: Lookupc() function "stuck"

Kenn

I've managed to use the lookupc() by following this sequence.

If I were writing this function, I would rearrange the sequence of the arguments, but that's another story....

So here is how I make sense of it.

Since the 3rd(return expression) and 5th(index name) argument are based on the 4th(table) argument, I enter the 4th argument prior to the other 2...

So type

lookupc(,,,,) and then back arrow to the 4th argument

lookupc(,,,<tablename>,) and press control down arrow.... you can than pick the tablename. Then move to the 3rd or 5th argument and finally to the 1st and 2nd argument...

I don't have the issue that you mention when entering the 2nd argument... It's not forcing a set of quotes around the value..