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In and Between QueriesQueries let you select records which answer a particular question. Most simple queries use an equals sign in the criterion to find all records matching a certain value. The "In" and "Between" expressions give you more flexibility. InFor example you could use an "In" expression to find customers in the UK, France, and Germany:
You could of course have written this on three lines of the grid as "=UK", "=Germany" and "=France" but the shorter form saves typing. The criterion can be inverted as "Not In(UK, France, Germany)" to give customers outside these countries. SubQueries takes this concept one stage further but you do need to know a little SQL to be able to use them. BetweenThe meaning or "Between" is probably obvious, it gives you the records which lie between two values. For example:
There is a subtle problem with this example. It will give you all the countries between "A" and "G" but it won't give you "Germany" because that lies after "G" in the alphabet. If you wanted to get all the countries beginning with "G" then change the criterion to Between "A" and "Gz". |
Hints & tips
The textbox class in Visual FoxPro 9 has a new Autocomplete
property which shows the user the previous values that have
been entered in that textbox.
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