|
|
Establishing Relationships
From NeoWiki
| Revision as of 02:35, 4 August 2007 (edit) Lorinda (Talk | contribs) (intro) ← Previous diff |
Revision as of 02:43, 4 August 2007 (edit) (undo) Lorinda (Talk | contribs) (types of relationships section) Next diff → |
||
| Line 1: | Line 1: | ||
| + | {{redbox|This article is part of the [[To Base and Back Again]] tutorial series.}} | ||
| + | |||
| Part of the power of Base is that it is a relational Database, allowing you to relate different tables of data. In order to make use of this power, we need establish the relationships between the various tables. In our case, not all the tables need to be related. The tables we "termed" [[Designing the Database "On Paper"#Planning_Convenience_Tables|covenience tables]] in the first article of this series, do not need to be related by an official process, as they will be used primarily for combo boxes and/or list boxes. The [[Designing the Database "On Paper"#Planning Essential Tables|essential tables]] do need to be related to each other. | Part of the power of Base is that it is a relational Database, allowing you to relate different tables of data. In order to make use of this power, we need establish the relationships between the various tables. In our case, not all the tables need to be related. The tables we "termed" [[Designing the Database "On Paper"#Planning_Convenience_Tables|covenience tables]] in the first article of this series, do not need to be related by an official process, as they will be used primarily for combo boxes and/or list boxes. The [[Designing the Database "On Paper"#Planning Essential Tables|essential tables]] do need to be related to each other. | ||
| + | |||
| + | ==Types of Relationships== | ||
| + | Relationships can be one-to-one or one-to-many. In a one-to-one relationship, one record in one table relates to one and only one record in another table. In a one-to-many relationship, one record in one table relates to more than one record in another table. In our database, the relationship between Field Trips and Sightings is one to many; on any given field trip, the birder would (hopefully!) see many birds. | ||
| + | |||
| + | ==Creating the Relationships== | ||
Revision as of 02:43, 4 August 2007
Part of the power of Base is that it is a relational Database, allowing you to relate different tables of data. In order to make use of this power, we need establish the relationships between the various tables. In our case, not all the tables need to be related. The tables we "termed" covenience tables in the first article of this series, do not need to be related by an official process, as they will be used primarily for combo boxes and/or list boxes. The essential tables do need to be related to each other.
Types of Relationships
Relationships can be one-to-one or one-to-many. In a one-to-one relationship, one record in one table relates to one and only one record in another table. In a one-to-many relationship, one record in one table relates to more than one record in another table. In our database, the relationship between Field Trips and Sightings is one to many; on any given field trip, the birder would (hopefully!) see many birds.
