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TransCAD
Managing Data Tables
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Create a New Table
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Add a field
Delete a field
Change the field order
Change a field name
Use a display name
Change a field type
Change a field width
Change the number of decimals
Set a default value in new records
Change a field format
Change a field description
Index a field
Change the aggregation method
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Adding Records to a New Table
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Adding Records to a New Table
Adding a Fixed Number of Records– If you know how many records you want to store in
the new table, you can tell TransCAD to add that number of blank records to the table.
Adding Matching Records– Use this option when you want to store additional
columns of information about records or map features in a new table. The Matching Records option automatically adds one matching record for each record or feature in the original dataview.
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Adding Records to a New Table
Adding a Record for Each Unique Value of a Field– Use this option when you want to create a
lookup table that adds new information to a map layer or dataview. To use this option, you must choose:
• The map layer or dataview you want to examine.
• The field whose values you want to use. TransCAD adds this field to the new table.
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Modify the Structure of a Table
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Working with Codes
Often a database will contain shorthand codes that have a particular meaning. Using codes saves space because long character strings are replaced with shorter codes.
To replace shorthand codes with descriptive text, you create a lookup table and attach it to the original table. A look up table is simply a table that contains the field names, the shorthand codes, and the descriptive text you eant to see displayed.
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Attach Codes
Lookup Table – All of the column data type has to be
character as well as the column contains codes
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Double Click
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Create a Lookup Table From a Dataview
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Create a New Table from a Dataview
Marking Column
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Creating a Table from an Excel File
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About Dictionary Files
Tables in fixed-format text, fixed-format binary, and comma- and tab-separated text format require an additional file called the dictionary file. The dictionary file serves as a header and tells TransCAD where to look in the data file for the different fields of data.
When you create a table in one of these formats, TransCAD automatically creates the dictionary file.
Dictionary files have the same file name as the data file and an extension of:– .DCT for a fixed-format text
file
– .DCC for a comma- or tab-separated text file
– .DCB for a fixed-fromat binary file
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