>I don't quite understand your example : > >"if the field numeric in the shapefile instead of be fill with numbers was >filled with '1', '2', '3', etc... >where the number are however not really numbers but text based, an action of >importing always 0.
>Will be more confusing. The user don't understand why a number (or >simil-number) became a '0'." > >In the DBF file itself, there is no difference between a 'text-based number' >and normal numbers. Whether I declare the column as numeric or text, the data >for the number one (1) will look the same. That will never be an issue. Hi, Unfortunately some difference in the declaration there are. the dbf specific are bit old-style and so are no fully coherent. See-ing the specific for the DBF III version ( http://www.wotsit.org/download.asp?f=dbase&sc=335163169 ) The char fields must contains always a set of chars filled with spaces. Not \0 termined. Unfortunately a quite famous tools of that time (clipper) redefine the db3 format (called xbase format) with a their version using the \0 to terminate the strings. (I think - to avoid the copyright put on the db3 format from original owner ashton-tate) So now there are tools that use the \0 terminate strings and tools that use the space-fill for the text fields. Instead for a numeric field nothing is say about how it must be filled because it is assume is always filled with digits. But if you put a text based value "27.57" in a numeric field of 18 digit. You can have many ambiguos situations For a 10.5 numeric field , I think the right version will be this "0027.57000" or "000027" (i think but I'm not sure) for a numeric 6.0 field so no space based and no \0 terminated because nothing is say about this in db3 format. instead if it is text based it can be for example: "27.57\0" and the remainis are spurious digits -> "27.57\0123" or "27.57" + "some spurious values" -> "27.57436x6" or for the 6.0 numeric field "27****" or "27\0**" Another situation where the interpretation is really impossibile is the Logical Field. In the db3 format It is define exactly with 1 chars using one of this: (YyNnTtFf space) But if I find a 'S' char value in a logical field of a db3. I cannot decide if it is a true of false value. So use a default to a False or True value is always an opinion. Andrea. -- ----------------- Andrea Peri . . . . . . . . . qwerty àèìòù -----------------
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