Table Concepts

This topic documents the concept of using code tables and lookup tables.

Code tables provide an efficient means of transferring data into the system with the attributes of the objects already pre defined based on the object feature codes.

Lookup tables provide an efficient means of converting feature codes of an incoming data set to the preferred feature codes of the user.

Code Tables

Code tables contain a list of feature codes and associated attribute settings which are used to set the attributes of data imported into the system either from a field survey or from some other source. They are created as files with CTB extensions and are stored in the User folder

Code tables therefore provide a very efficient means of importing data with the required pre defined attributes.

Two code tables are supplied with the system.

ALPHAxx.CTB is a typical example of a code table utilising alpha feature codes.

NUMERICxx.CTB is a typical example of a code table utilising numeric feature codes.

You may use either of these tables, modify them to suit your requirements, or create new tables to suit your particular needs.

When data is imported into the system, any point or line object with a feature code defined in the selected code table will be imported with the attributes as defined in that code table. If a feature code of an object being imported is not present in the selected code table, the object is created with a DEFAULT feature code. Every code table has a DEFAULT feature code.

See Also

Utilities/Tables/Code Table

(for creating or opening code tables)

Code Table

(for details of the attributes that may be set via the code table)

Code Table Editor

(for editing code tables)

Lookup Tables

A lookup table consists of pairs of alphanumeric codes. For each pair, the first code must be a feature code defined in the selected code table, and the second code is the corresponding feature code in an incoming data set.

Lookup tables are created as files with LUT extensions and are stored in the User folder

A lookup table is used to match the feature codes of the incoming data set to the feature codes in the selected code table, thereby quickly setting the attributes of data imported into the system from some other source, without the need to set up a special code table.

Two lookup tables (ALPHAxx.LUT and NUMERICxx.LUT) are supplied with the system.

ALPHAxx.LUT is a lookup table for converting from alpha feature codes in an incoming data set to the numeric feature codes used in the NUMERIC.CTB code table.

NUMERICxx.LUT is a lookup table for converting from numeric feature codes in an incoming data set to the alpha feature codes used in the ALPHA.CTB code table.

You may use either of these tables, modify them to suit your requirements, or create new tables to suit your particular needs.

Use of a lookup table is optional. If a lookup table is not used, then each code in the incoming data set should be defined in the selected code table. If it is not present in the code table, then the object will be assigned to the DEFAULT code and attributes.

See Also

Utilities/Tables/Lookup Table

(for creating or editing lookup tables)

Lookup Table dialog box

(for editing lookup tables)