Description of the use of short int, long, float, double _access

Short int 2-byte value range -32768~32767
Long integer 4 byte value range -2147483648~2147483647 float Precision 4 byte value range -3.4*10 (-38) ~3.4*10 (38)
Double Double-precision 8 byte value range -1.7*10 (-308) ~1.7*10 (308)


This problem occurs when Access data is exported to DBF, and the field width in dbf does not refer to the number of bytes in the field in Access, but the number of characters. In dbf, integers and floating-point numbers are stored as characters. For example: 3.134 is stored as "-3.135" and takes up 6 characters.
So
For short integers in Access, the field width stored in DBF is 6;
For long integers in access, the field width stored in DBF is 11;
For single precision in Access, the field width stored in DBF is 18, and the decimal digit is 7;
For double precision in access, the field width stored in DBF is 24, and the decimal digit is 15.
That is, in access the single precision, double precision data, dump to DBF is difficult to ensure accuracy.