连接属性

在查询设计中,如果双击两个链接字段之间的连接,或者选择 插入 - 新关系,将弹出连接属性对话框。这些属性将会被应用在此后创建的所有查询中。

要访问此命令...

打开查询设计并选择 插入 - 新建关系,或双击两个表格之间的连接线。


涉及的表格

指定要连结的两个表格。

涉及的字段

指定将通过关系连接的两个数据字段。

选项

类型

Specifies the join type of the selected join. Some databases support only a subset of the various possible types.

内部连结

In an inner join, the results table contains only those records for which the content of the linked fields is the same. In LibreOfficeDev SQL this type of link is created by a corresponding WHERE clause.

左侧连结

In a left join, the results table contains all records of the queried fields from the left table and only those records of the queried fields from the right table for which the content of the linked fields is the same. In LibreOfficeDev SQL this type of link corresponds to the LEFT OUTER JOIN command.

右侧连结

In a right join, the results table contains all records of the queried fields from the right table and only those records of the queried fields from the left table for which the content of the linked fields is the same. In LibreOfficeDev SQL this type of link corresponds to the RIGHT OUTER JOIN command.

完整连结

In a full join, the results table contains all records of the queried fields from the left and right tables. In the SQL of LibreOfficeDev this type of link corresponds to the FULL OUTER JOIN command.

自然

In a natural join, the keyword NATURAL in inserted into the SQL statement that defines the relation. The relation joins all columns that have the same column name in both tables. The resulting joined table contains only one column for each pair of equally named columns.