以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。
The following two tables lists all constants defined by the paradox extension.
| Name | Meaning |
|---|---|
| PX_FIELD_ALPHA | Character data with fixed length |
| PX_FIELD_DATE | Date, number of days since 1.1.0000 |
| PX_FIELD_SHORT | Short integer (2 Bytes) |
| PX_FIELD_LONG | Long integer (4 Bytes) |
| PX_FIELD_CURRENCY | same as PX_FIELD_NUMBER |
| PX_FIELD_NUMBER | Double |
| PX_FIELD_LOGICAL | Boolean |
| PX_FIELD_MEMOBLOB | Binary large object |
| PX_FIELD_BLOB | Binary large object (not supported) |
| PX_FIELD_FMTMEMOBLOB | Binary large object |
| PX_FIELD_OLE | OLE object (basically a blob, not supported) |
| PX_FIELD_GRAPHIC | Graphic (basically a blob, not supported) |
| PX_FIELD_TIME | time, number of milli seconds since midnight |
| PX_FIELD_TIMESTAMP | timestamp, number of milli seconds since 1.1.0000 |
| PX_FIELD_AUTOINC | Auto incrementing interger (like PX_FIELD_LONG) |
| PX_FIELD_BCD | Decimal number stored in bcd format (not supported) |
| PX_FIELD_BYTES | Array of Bytes with not more than 255 bytes (not supported) |
| PX_KEYTOLOWER | Turn all field names into lower case |
| PX_KEYTOUPPER | Turn all field names into upper case |
| Name | Meaning |
|---|---|
| PX_FILE_INDEX_DB | Indexed database |
| PX_FILE_PRIM_INDEX | Primary index |
| PX_FILE_NON_INDEX_DB | None indexed database |
| PX_FILE_NON_INC_SEC_INDEX | None incremental secondary index |
| PX_FILE_SEC_INDEX | Secondary index |
| PX_FILE_INC_SEC_INDEX | Incremental secondary index |
| PX_FILE_NON_INC_SEC_INDEX_G | Non incremental secondary index |
| PX_FILE_SEC_INDEX_G | Secondary index |
| PX_FILE_INC_SEC_INDEX_G | Non incremental secondary index |