Join Column wizard |
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Join method |
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This second page of the Join Column wizard lists the possibilities for joining based on a comparison of the domains that exist or are used by the two tables and their columns. Remember that the two tables including their columns should at least share one common domain, the key. The key through which a join can be performed should be a common class or ID domain.
On this page you need to choose the join method you wish to use. In principle, there are four methods to join, see below. The wizard will help you to make the correct choice.
Dialog box options:
The four possible join methods and the options on this page are:
You can use this method when the domains of the two tables are the same; the tables have a 1 to 1 relation. The link between the two tables will be made through the common domain of both tables.
When you click the Next button, the wizard will continue with the Specify output column name page.
You can use this method when the domain of a column in the current table is the same as the domain of the selected table; the current table has a many to 1 relation with the selected table. The link between the two tables will be made through the domain of a column in the current table (key1) and through the domain of the selected table (key2).
When you click the Next button, the wizard will continue with the Link between tables page, on which you need to select a column from the current table (key1) to create the link between the two tables.
You can use this method when the domain of the current table is the same as the domain of a column in the selected table; the current table possibly has a 1 to many relation with the selected table. The link between the two tables will be made through the domain of the current table (key1) and through the domain of a column in the selected table (key2).
When you click the Next button, the wizard will continue with the Link between tables page, on which you need to select a column from the selected table (key2) to create the link between the two tables.
Then, later on, the Aggregation method page of the wizard will appear, in which you can select an aggregation function and, optionally a weight column.
You can use this method when the domain of a column in the current table is the same as a domain of a column in the table from which you want to obtain data; the current table possibly has a many to many relation to the selected table. The link between the two tables will be made through the domain of a column in the current table (key1) and through the domain of a column in the selected table (key2).
When you click the Next button, the wizard will continue with the Link between tables page, on which you need to select a column both from the current table (key1) and from the selected table (key2) to create the link between the two tables.
Then, later on, the Aggregation method page of the wizard will appear, in which you can select an aggregation function and, optionally a weight column.
When you click the Next button:
Tip: Experienced users may also join columns from other tables by typing an expression on the TabCalc command line. For more information, see Table calculation : joining columns from other tables. This topic also provides some examples, both for using the wizard and for using the command line.
See also:
Join Column wizard - Link between tables