EDB table property sheet contains a number of properties which are determined by the data source and can be viewed only by ObjectLand tools. They cannot be changed directly.
At figure 42-2 the page “General” is shown. It contains a name of EDB table, owner of the corresponding component of data source (if the source provides the notion of an owner), component type of the source on the basis of which the EDB table was created (as it was pointed out above, the following types are possible: table, view, system table and synonym) and also text description of table which can be determined for some types of data sources.
Figure 42-2. Property sheet “Properties of table”, page “General”
On page “Permissions” (figure 42-3) four checkboxes are located which indicate whether this user has permissions to perform four basic actions with table records: update (that is, change field values), insert, delete and select records from external data source.
Figure 42-3. Property sheet “Properties of table”, page “Permissions”
Pages of properties “Indexes”, “Primary keys” and “Foreign keys” are connected with the corresponding notions determined in SQL language. Indexes can be viewed as additional information stored in the data source together with the table and used to speed up the process of searching records by specified values of one or several fields. The notion of an index is close to the notion of a key field in internal tables of ObjectLand. The primary key of a table is a field or a set of fields which identifies the record uniquely. The foreign key is a field or a set of fields used to build join with some other table of the same source. More detailed data on these notions can be obtained in manuals on SQL.
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