Table tools
When a table has been loaded, either from the “Project manager” or from the view, the tools associated with the table will appear in the tool bar.
A new menu, called “Table”, will also be activated in the tool bar. This can also be used to access the different tools.
You can access this option by clicking on the following button
or by going to the “Table” menu and then to “Statistics”.
The “Statistics” tool allows you to obtain the most common statistical values.
N.B.: Remember that the tool will not be activated until you select a numerical field.
If you wish to obtain field statistics, select the field (left click on the field heading), then click on the “Statistics” tool.
You can only obtain statistics from a series of records, firstly, select the field the values are located in, then select the desired records, and click on the “Statistics” tool.
You can access this tool by clicking on the “Filter” button in the tool bar
or by going to the “Table” menu and then to “Filter”. The “Filter” tool works in much the same way as in the “Views” section.
gvSIG allows selections to be made using filters. Selection using filters allows you to define exactly what you want to select, including several attributes, operators and calculations.
Requests can be made using logical operators, such as “equals” “more than” “different from”, etc.
If you press the “Filter” button in the tool bar, a dialogue window will appear to define your request.
Fields: Double click on the field you wish to add to your request from the “Fields” list in the layer.
Logical operators: These allow you to insert a logical expression into your query by clicking on them.
Values: This shows a list with the different values the selected field has. If you wish to add a value to the request, double click on it.
Request: This is the window which represents the request to be made. You can write here directly.
Selection buttons: These buttons make the request using:
- “New set” (deletes any previous selections).
- “Add to set” (adds the elements selected by the query to the existing elements).
- “Select from set” (makes the request from the selected elements).
N.B.: In a gvSIG view, when you activate a layer by selecting it in the ToC, the filter tool will also be activated in the tool bar, even though no table has been loaded. This allows you to work with the table associated with the selected layer. The "Table" menu will also be added in the menu bar. This provides another way to access the filter tool when it drops down.
You can access this tool by clicking on the following tool bar button
or by going to the “Table” menu and then to “Ascending order”.
The “Ascending order” tool allows you to order the table records.
- It orders the values from the lowest to the highest in a numerical field.
- It orders the records in alphabetical order, starting from “A” in a text field.
You can access this tool by clicking on the following tool bar button
or by going to the “Table” menu and then to “Descending order”. The “Descending order” tool allows you to order the table records. It orders the values from the highest to the lowest in a numerical field. It orders the records in alphabetical order, starting from “Z” in a text field.
The “Join” tool allows two tables to be joined via a common field. You can also access this tool by clicking on the following button
or by going to the “Table” menu and then to “Join”. To join the two tables, carry out the following steps: Firstly, specify the source table the join is to be made from.
Then specify the field to be used for the join.
Then indicate the table you wish to join to the first one.
Finally, indicate the field in the second table which is common to the first one.
If you open the data source table, you will see that the fields of the destination table have been joined. The name of the field added to the table is identified by the word “Join_(Field name)”
This tool allows the records selected in the table to be moved to the top of the table. You can access this tool by clicking on the following button in the tool bar
or by going to the “Table” menu and then to “Move selection to top”. The following table shows an example in which two records have been selected to move to the top of the table.
If you click on the button, the table will change the position of the selected records.
Although .dbf files should contain a byte to indicate character encoding, this information is usually not present. gvSIG provides the Shalom tool that sets the encoding and then reads the information in the table using that encoding. If the encoding is not set in this way then gvSIG will read the table data using the default encoding.
It is possible to set the character encoding of a table by selecting Table > Set encoding to .dbf files from the menu bar. Choose the table for which the encoding needs to be set and then select the encoding type (charset). This encoding setting is recorded permanently in the table.
Now the table can be added to the gvSIG project. When gvSIG opens the table the character encoding is read and the characters in the table are correctly displayed.
Note: The correct display of characters depends not only on the encoding setting, but also on the virtual machine that is installed (specifically Java 1.6, which supports more encodings than Java 1.5).
This option can be accessed by opening the Window > Preferences menu and then selecting DBF default encoding.
gvSIG will use the selected encoding as the default when adding a .dbf file to a project, and will also use it when exporting a table that uses a specific encoding.
The export of a table might not be correct if the character encoding is incorrectly configured in the gvSIG preferences.
