Use the New/Modify Table Structure dialog box to specify the field name, field type, number of characters (width), and whether or not the field is to be indexed for each field in your new database.
You also indicate whether the table is mappable by associating graphic objects with records and, if so, whether the map is to be an earth or a non-earth map. Collectively, this information is the structure of your database.
If you are using the structure from another mappable table, then MapInfo Pro sets the new table projection to the projection of the source table.
At the top of the New Table Structure dialog box is a box that lists the fields in order from top to bottom. To choose a field from this box, click on its name and the field is highlighted.
All tables must have at least one field, so even if you do not need any data fields, you should create one anyway.
Field
This column contains the names of the fields (columns) in the table from top to bottom.
Type
Indicates the type of field with the number of characters in the field listed in parentheses (where applicable).
Indexed
An X in this column indicates the field is indexed. When the column is blank, the field is not indexed. You can index a maximum of 28 fields (click index box). Indexing does not change the order of records. But, you need it to:
Use the Find command, which only works on an indexed field. (This command is located on the MAP tab, in the Selection.)
Speed up queries containing numerical and alphabetic comparisons.
Speed up joins.
Up/Down
Allows you to move the selected field up or down one position in the list box. The file structure is reorganized accordingly. Moving a field up or down has the effect of moving it left or right in a Browser. When a table displays in a Browser, the first field becomes the left most column, the second field becomes the second column from the left, and the last field becomes the right most column.
Add Field
Allows you to add a new field at the bottom of the list. This field has a default name of field1, field2, field3, etc., depending on the order in which the field was created.
Remove Field
Allows you to remove the selected field from the table.
Table is Mappable
When this option is checked, MapInfo Pro modifies the table so you can map it and create graphical objects. If you do not check this option, you can make the table mappable at a later time by using the Modify Structure command (which is located on the TABLE tab, in the Maintenance group, on the Table list). The Modify Structure dialog box is identical to the New Table Structure dialog box. Check the Associate graphic objects with records box, and MapInfo Pro modifies the table so you can map it.
The availability of the Table is Mappable check box and the default projection depends on the Create New Table selections that were previously made in the New Table dialog box. MapInfo Pro sets the projection to default table projection, when making a table mappable.
Projection button
This option allows you to access the Choose Projection dialog box. See Saving a Copy of Your Table in a Different Projection.
Field Information
Allows you to specify information about the fields.
Name
Allows you to enter the name of the new field in the Name box. Defaults are field1, field2, etc. A field name can be up to 31 alphanumeric characters long. You can use letters, numbers, and the underscore. Do not use spaces; instead, use the underscore character (_) to separate words in a field name. You can use upper and lowercase for legibility, but MapInfo Pro is not case-sensitive.
Type
A drop-down list is used to indicate the field type. The following types are available:
- Character: Stores up to 250 alphanumeric characters. You cannot perform arithmetic operations on numerals in a character field. You should store ZIP Code information in character fields, otherwise leading zeros are dropped.
- Integer: Whole numbers (without a decimal) from -2,147,483,648 to +2,147,483,647 (inclusive); stored in 4 bytes.
- Small Integer: Whole numbers from -32768 to 32767 (inclusive); stored in 2 bytes.
- Large Integer: Whole numbers from –9,223,372,036,854,775,808 to +9,223,372,036,854,775,807 (inclusive); stored in 8 bytes.
- Float: Stores numbers in floating-point decimal form.
- Decimal: Stores numbers in fixed-point decimal form. Do not put commas in decimal.
- Date: These fields can contain a calendar date in the format MM/DD/YYYY. The year can be specified by two or four digits and is optional. Use slashes or hyphens to separate components of a date. The following are valid dates: 01/23/91, 5-6-1989, 10/07.
- Time: These fields contain time-based information in the format HHmmssfff, where HH refers to hours, mm refers to minutes, ss refers to seconds and ff refers to fractions of seconds.
- Date/Time: These fields contain date and time-based information in the format yyyyMMddHHmmssfff where yyyy refers to years, MM refers to month, dd refers to date, HH refers to hours, mm refers to minutes, ss refers to seconds and ff refers to fractions of seconds.
- Logical: These fields contain only true/false or yes/no information, stored as T for true/yes and F for false/no. Decimal, integer, small integer, and float can only contain numeric symbols. These fields do not accept any characters besides numbers, the minus sign, or decimal points for decimal and floating-point numbers.
Width
Type the number of characters in the field (character and decimal fields only). Maximum field width is 250 for character fields and 19 for decimal fields. A valid decimal value has a total number of characters, including the decimal point, minus sign if negative, and padding to precision if necessary, not to exceed the decimal width.
Navigation Buttons
Cancel
Cancels the operation.
OK
Creates a new table with the structure you have specified in the dialog box. When you are creating an earth map, or if the table is not mappable, MapInfo Pro displays the Create New Table dialog box. When you are creating a non-earth map, MapInfo Pro displays the Non-Earth Coordinate System dialog box. After that, the Create New Table dialog box displays.
See Also: