MapInfo TAB and MIF/MID
MapInfo datasets in native (TAB) format and in interchange (MIF/MID) format
are supported for reading and writing. Update of existing files is not
currently supported.
Note: In the rest of this document "MIF/MID File" is used to refer to a
pair of .MIF + .MID files, and "TAB file" refers to the set of files for a
MapInfo table in binary form (usually with extensions .TAB, .DAT, .MAP, .ID,
.IND).
The MapInfo driver treats a whole directory of files as a dataset, and
a single file within that directory as a layer. In this case the directory
name should be used as the dataset name.
However, it is also possible to use one of the files (.tab or .mif) in a
MapInfo set as the dataset name, and then it will be treated as a dataset
with one single layer.
MapInfo coordinate system information is supported for reading and writing.
Creation Issues
The TAB File format requires that the bounds (geographical extents) of a new
file be set before writing the first feature. However, there is currently
no clean mechanism to set the default bounds of a new file through the
OGRDataSource interface.
We should fix the driver at some point to set valid default bounds for
each projection, but for the time being, the MapInfo driver sets the following
default bounds when a new layer is created:
- For a file in LAT/LON coordinates: BOUNDS (-180, -90) (180, 90)
- For any other projection: BOUNDS (-30000000, -15000000) (30000000, 15000000)
MapInfo feature attributes suffer a number of limitations:
- Only Integer, Real and String field types can be created. The various
list, and binary field types cannot be created.
- For String fields, the field width is used to establish storage size in
the .dat file. This means that strings longer than the field width will be
truncated.
- String fields without an assigned width are treated as 254 characters.
To create MID/MIF instead of TAB files use the dataset creation option
"FORMAT=MIF".
See Also