Propietats de la unió
Per obrir el diàleg Propietats de la unió, feu doble clic a una connexió entre dos camps enllaçats al disseny de la consulta, o bé trieu Insereix - Relació nova. Estes propietats s'utilitzaran per a totes les consultes que creeu en el futur.
Taules implicades
Indica les dues taules que voleu unir.
Camps implicats
Indica els dos camps de dades que quedaran units per una relació.
Opcions
Tipus
Specifies the join type of the selected join. Some databases support only a subset of the various possible types.
Unió interna
In an inner join, the results table contains only those records for which the content of the linked fields is the same. In LibreOffice SQL this type of link is created by a corresponding WHERE clause.
Unió esquerra
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 LibreOffice SQL this type of link corresponds to the LEFT OUTER JOIN command.
Unió dreta
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 LibreOffice SQL this type of link corresponds to the RIGHT OUTER JOIN command.
Unió completa
In a full join, the results table contains all records of the queried fields from the left and right tables. In the SQL of LibreOffice this type of link corresponds to the FULL OUTER JOIN command.
Natural
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.