Drop down box. not seen before and would like to know how it works. (1 Viewer)

[rainbows]

i saw a drop down box that had supplier attached to parts but you could select more than one supplier ,
i copied it to my database and adjust a couple of things and it works but i dont know how it gets done and really would like to know where does the tick box come from
thanks
steve

 

[theDBguy]

Hi. It's called a Multi Value Field or MVF for short. You create it by selecting Yes to Allow Multiple Values. Most developers avoid using it. You can find a lot of discussions about it if you search for MVF.

 

[rainbows]

thanks

 

[The_Doc_Man]

The short discussion of why you want to avoid a table-level multi-valued field is that the VBA and form design using an MVF becomes more complex than using a FORM-level multi-valued field - which is either a list-box or combo-box control where YOU get a lot more options of how it looks and what it does. An MVF locks you into a certain methodology whereas form-level actions can be darned near anything.

 

[Pat Hartman]

I know the control is cool but it comes with too much baggage. Take the expert advice to avoid table level lookups and stick to ordinary combos or listboxes on forms.

 

[MajP]

You can use my fake mvf, but it takes some vba knowledge.

Faking a Multi Value Field

I have seen a few posts lately on people wanting to use multi valued fields. Most Access developers steer away from them and build their own related tables. Although they are properly normalized and work well, they can get very confusing even if you know the ins and outs. I wanted to see if I...

www.access-programmers.co.uk

 

[rainbows]

ok . thanks , i was only thinking how it would help identify what suppliers are on the system for a certain part. see below these parts have been identified as items to make an assembled part so i could choose any of them 2

 

[gemma-the-husky]

If you want multi-select, Instead of a combo box, you can have a list box with multi select.

You can then either toggle selections on/off one at a time, or select a range with shift-click (maybe slightly different)
That's standard access, and different technology to a MVF, so will upsize to a different database type.

 

[rainbows]

but can you just list see 1 or more supplies of any part. ? i am thinking if you are new to the company i am showing you what suppliers to use

 

[rainbows]

i have 18000 parts on the system and maybe 500 suppliers

 

[Pat Hartman]

What is the point of showing the potential suppliers on this form? It doesn't matter whether you use a multi-value field or a string. I don't see the point. If you want to order an item, you start the order. The combo on the order will let you choose the supplier. OR you do it the other way around. You create a PO and then choose from the list of items provided by that supplier.

 

[CJ_London]

The point about a MVF is it allows you to select ‘more than one’. E.g. deliveries can be made on these days’. when placing an order it is on one supplier, not multiple suppliers, so just use a standard combo box