logicalType
A database independent name indicating the data type of the value stored in a field.
Property of
CalcField, DbfField, Field, PdxField, SqlField
Description
Each database engine has its own set of data types that are referred to as its native data types. A data type in one database engine may be physically identical to a data type used by another database engine, but have a different name.
Mapping these native types to a set of database independent (logical) data types allows physically identical data types to have the same logicalType even when their native data types differ.
For example, the logical type for both a Paradox table’s, “Alpha”, field and a dBASE table’s, “Character”, field is “ZSTRING”. This indicates they are both character strings with a null byte at the end of the string.
Note: The Field object’s type property contains the native type of a field.
The following table lists possible values for the logicalType property:
logicalType |
Description |
UNKNOWN |
|
ZSTRING |
Null terminated character string |
DATE |
Date (32 bit) |
BLOB |
Short for, "binary large object", a collection of binary data stored as a single entity in a database management system. |
BOOL |
Boolean |
INT16 |
16 bit signed integer |
INT32 |
32 bit signed integer |
FLOAT |
64 bit floating point |
BCD |
Binary Coded Decimal |
BYTES |
Fixed number of bytes |
TIME |
Time (32 bit) |
TIMESTAMP |
Time-stamp (64 bit) |
UINT16 |
Unsigned 16 bit integer |
UINT32 |
Unsigned 32 bit integer |
FLOATIEEE |
80 bit IEEE float |
VARBYTES |
Length prefixed string of bytes |
LOCKINFO |
Lock for LOCKINFO typedef |
CURSOR |
For Oracle Cursor type |
Tip: Using the logicalType property, you could write a dBASE Plus program to check whether data from a table containing a DbfField data type can be copied to a table containing a PdxField data type.