The composition of tables in MapInfo, the meaning of tabs, ID, dat, map, and other files

In Mapinfo, the table refers to a simple combination of data tables or graphs and data. A typical MapInfo table mainly consists of *. tab, *. dat, *. wks, *. DBF,

*. Xls, *. Map, *. ID, *. Ind file format. After creating a MapInfo table, the table consists of at least two independent files.

1. Table Structure file of attribute data. Tab: The structure file of the attribute data table defines the table structure of map attribute data, including the number of fields, field names, field types, and fields

Width, index field, and some key space information descriptions of the corresponding layer .. The tab file is actually a text file. You can open it on the WordPad to view its content.

2. attribute data file. DAT: The attribute data file stores the complete map attribute data. The table structure is described after the file header, followed

Specific attribute data records.

3. Cross-index file. ID: the cross-index file records the position pointer of each spatial object in the map in the spatial data file (. MAP. Each four bytes constitutes

Needle. The order of pointer sorting is the same as that of storing attribute data records in the property data file (. dat. The cross-index file is actually a positioning table of a spatial object.

4. Spatial Data File. MAP: contains the spatial data of each map object. Spatial data includes the geometric type, coordinate information, and color information of spatial objects. In addition

It also describes the record number of the Property Data Record of the space object in the property data file (. dat. In this way, when a user queries a map object from a map

You can find the relevant property information.

5. index file. Ind: The index file is not required. Only after you specify the database index field will MapInfo automatically generate the index file. Index File

Each file index field has an index table. In each index table, the total number of database records is given first, and then each attribute data record is given according to the index order.

The specific attribute data at the corresponding index field and the record number in the attribute file (. dat) and cross-index file (. ID.

The preceding description shows that the centralized file types are not all MapInfo file formats. They are only common formats.

During a series of operations, files in other formats will be generated in the directory where map files are stored.

In addition:
. Mid: Format of MapInfo transfer in/out for table data;
. MIF: the format of MapInfo transfer-in/transfer-out for graphic objects;
. Wor: a workspace file of Mapinfo, used to save information about tables and Windows used in a MapInfo interaction.