Collecting of the table

For relational DBMS given miscellaneous category is kept in miscellaneous table. This allows to exclude redundancy to information. Distinguish several types relational relationship.

In practice most often meets the relationship one-to-many (1:М). Under such type relationship each record main tables can be put(deliver)ed in correspondence to one or several records, so named, subordinated tables.

For making relationship necessary to define the primary key, both for the main and for subordinated tables. The Determination of the primary key for subordinated tables though and is not obligatory, but vastly enlarges the velocity of the work. For subordinated tables it is necessary to define the field of the secondary key, type data and size, which comply with floor of the primary key main tables. The Secondary keys differ from primary that that for they are allowed presence of alike importances flap.

MS Access automatically keeps a check on provision of wholeness data. If edit record in subordinated to table, that this record can be preserved in that event only if importance of the connecting field is present in the main to table. When editing main tables possible to delete record in that event only if this record is not connected with writing the subordinated table.

The Tables link in mode of the shaping the scheme BD, herewith for determination relationship 1 : M necessary to install the mouse on primary key main tables and afterwards drag the communication link before subordinated tables. The Features relationship are assigned in addition.

Additional state of working with database

Under practical usage database, created with use MS Access appears need of the general copying BD, reconstruction BD after malfunctions, compressions BD and finally репликации mode of the reception to current copy with possibility of the usages her(it) on figurative or insulated computer with the following synchronizing both mines BD.

The Compression BD necessary, when You very intensive modify BD or in process of the development new object (the tables, the forms, reports, request, modules) or in process of the accompaniment and removing data. In these cases all deleted objects and given delete logically i.e. physically file are located inwardly *.mdb, which grows vastly and more is in a complicated way administerred. Exactly for this and is used mode of the compression. The Operation of the compression is conducted on locked BD, is recommended first assign compressed BD new name and only after successful termination to operations to delete get old copy and переименовать сжатую BD. For undertaking the operations of the compression necessary to choose the menu a SERVICE > Cлужебные program >Compress.

In menu SERVICE is found also mode to Restore the base, which is used after breach of wholeness of the file BD, and mode to convert the base, which is used for transformation BD from more early version Access 2.0 and Access 7.0

Besides in service SERVICE are found else sections, connected with different adjustment. To he pertain:

• Division BD on 2 interconnected parts, in one of which are found all tables, but in the other objects of their processing: the forms, requests, reports, modules. Such division provides the most efficient way to usages of the system, since modification object processing can be produced apart and both files link only with use the special mode of the superstructure of the Traffic manager of the bounded tables.
• The Traffic manager of the button forms, which provides quick and flexible development of the external interface of the system, defining list main state of working and their hierarchy.

The Connection of the tables is to database possible to realize and other way: in menu FILE> External given > Relationship with table. Besides possible import the tables from the other database wholly, created in MS Access and even from the other database in other format, however at import table is converted and copied in the current BD wholly.

The author: Y.N.Antonov Is added: 25.06.2008