From Dwayne Wright PMP, PMI-ACP, CSM
Certified FileMaker Developer
The number field format is normally used for fields that contain quantity related information. Quantity values are often used within calculations, particularly when reporting is involved. Examples of a quantity related value data could be... price, weight, space, quantity or height.
FYI ... If the data string is a number but not related to a quantity, a text field is usually chosen instead of a number field. Some examples of this are U.S. zip codes, phone numbers or the jersey numbers of a sports team.
A number field is designed to hold only one number, unless of course it is a repeating field ( which is a whole different kettle of fish ). When it comes to indexing, number fields will index the first 400 digits, which is quite a bit. We should mention that this is 400 digits in each direction of zero. So you can index 400 digits above the value of zero and you can index 400 digits below the value of zero.
Number fields can be searched upon, sorted, used in calculations or in summary fields. You can enter formatting into a number field but generally it is not necessary. While in layout mode, you can set up the field to show comma's, dollar signs, percent signs or more. If you enter formatting related characters in a number field, FileMaker will not penalize you for it. For example, if you enter in the dollar sign ( $ ) and format the number field to show the dollar sign, FileMaker will not show the dollar sign twice. You can setup the number field options by choosing number under the Format menu while in layout mode.
You can put text characters in a number field but almost all text characters are ignored by the index. Since text characters are ignored by the index, find / sort / relationship operations on a number field that have text within it, will not work. As far as those operations go, the text characters might as well not be there. So in other words, if a number field has " (512) 555-1212 Extension 12, FileMaker only sees 512555121212. If the number field has 2250 Ridgepoint Drive, Suite 1007, FileMaker sees only the numbers of 22501007.
TEXT CHARACTER IN A NUMBER FIELD EXCEPTIONS
A carriage return is one of the text characters that a number field will not accept because it would basically mean two numbers in one field and that is not possible. FileMaker will recognize a period character as a decimal point. The text character of a minus sign ( - ) in the front of a number would be seen as making the following digits a negative number.
There is a field validation option that can be used to make sure that text characters are not entered into number fields. However, validation can be defeated in some cases of scripting and importing of data.
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