下列的參考資料十分不錯，列出大部分用到的資料庫欄位型態，寫程式時還蠻有用的！
Databases - Field Types http://mc-computing.com/Databases/FieldTypes.html
ex:
Foxpro
| Type | Size | Description |
|---|---|---|
| Character | 1 to 254 | |
| Currency | 8 bytes | 18 significant figures, including 4 decimal places Not available in Database Explorer |
| Date | 8 bytes | January 1st, 1 A.D to December 31st, 9999 A.D |
| DateTime | 8 bytes | |
| Logical | 1 byte | |
| Variant | Can hold any type of field | |
| Double | 8 bytes | +/-4.94065645841247E-324 to +/-8.9884656743115E307 13 significant figures This range does not make sense |
| Numeric | 1 to 20 bytes | - .9999999999E+19 to .9999999999E+20 up to 10 significant figures (specified by the user), same as Float |
| Float | 1 to 20 bytes | - .9999999999E+19 to .9999999999E+20 up to 10 significant figures (specified by the user), same as Numeric |
| Integer | 4 bytes | -2,147,483,647 to 2,147,483,647 |
| Integer (Autoinc) | 4 bytes | Autoincrement field |
| General | 4 bytes in table | Reference to an OLE object The type is OLE in Database Explorer |
| Memo | 4 bytes in table | Values may be modified depending on the language mapping Database Explorer indicates that these are actually 10 bytes each |
| Memo (Binary) | 4 bytes in table | Values are not modified When the code page changes |
