First - the relationship (one to one) or (One To One)
This kind of relationship means that the data one record of a particular table data has only one record from another table.
If we had two tables (and staff salaries) Valmtaref it that each employee salary and only one will appear after the relationship linking format as in the picture
(1-1) We also note the appearance of a sign (1) of each point of the agenda and this shows the type of relationship between the two tables
Secondly - the relationship (one to many) or (One To Many)
Also called one-to-many ... and more importantly, to understand the importance of the relationship and not the label ... and this relationship is
The most commonly used in databases, which means that each record from the records of the first table, which
Usually contains (primary key) has more than one record or multiple records in the other table, which
Usually (key contains secondary) .. as in the picture (1-2) .. We also note the appearance of a sign (1) on the one hand and the emergence of the main table sign (e - e) of the table the other hand (secondary)
Thirdly - the relationship (many to many) or (Many To Many)
It is the relationship more complex and less used and is used when we have two tables and want to have for each record in the first table the number of
Records in the second table, as well as the opposite to be the agenda of the second number of records in the first table (and here are the node) ...
So you should work schedule (broker) has a (secondary keys) and we only binds each (master key) of tables (I and II)
Table (median) relationship (one to many) between each of the two presidents tables and table mediator and thus we will be able to link data tables
The key is for each record number of records in the other table ..
For example, if we had the first two tables (professors) and second (grades) it is known that each professor teaches more than one row, and each row is taught
More than a professor must therefore work schedule (broker) for the completion of this relationship and also in the picture (1-3)
As we note that the relationship between the two tables (professors and rows) table with (mediator) is a kind of (one to many
First - the relationship (one to one) or (One To One)
This kind of relationship means that the data one record of a particular table data has only one record from another table.
If we had two tables (and staff salaries) Valmtaref it that each employee salary and only one will appear after the relationship linking format as in the picture
(1-1) We also note the appearance of a sign (1) of each point of the agenda and this shows the type of relationship between the two tables
Secondly - the relationship (one to many) or (One To Many)
Also called one-to-many ... and more importantly, to understand the importance of the relationship and not the label ... and this relationship is
The most commonly used in databases, which means that each record from the records of the first table, which
Usually contains (primary key) has more than one record or multiple records in the other table, which
Usually (key contains secondary) .. as in the picture (1-2) .. We also note the appearance of a sign (1) on the one hand and the emergence of the main table sign (e - e) of the table the other hand (secondary)
Thirdly - the relationship (many to many) or (Many To Many)
It is the relationship more complex and less used and is used when we have two tables and want to have for each record in the first table the number of
Records in the second table, as well as the opposite to be the agenda of the second number of records in the first table (and here are the node) ...
So you should work schedule (broker) has a (secondary keys) and we only binds each (master key) of tables (I and II)
Table (median) relationship (one to many) between each of the two presidents tables and table mediator and thus we will be able to link data tables
The key is for each record number of records in the other table ..
For example, if we had the first two tables (professors) and second (grades) it is known that each professor teaches more than one row, and each row is taught
More than a professor must therefore work schedule (broker) for the completion of this relationship and also in the picture (1-3)
As we note that the relationship between the two tables (professors and rows) table with (mediator) is a kind of (one to many