| A | B |
|---|
| AutoNumber | A field type wherein the values are automatically incremented each time a new record is created. Typically used for Artificial or Surrogate Primary keys. |
| Calculated field | A field which is not in an underlying table but is calculated via a query expression. |
| Data type | The kind of data - numeric, text, etc., that a field contains. |
| Entity | Usually an object such as a customer or product but also events such as sales or purchases. |
| Field | A single element of information such as first name or city. |
| NULL | Sounds like it should mean NIL, or nothing but it doesn't. It means missing or unknown. |
| One-to-many relationship | A relationship between two entities. An example would be an EMPLOYEE table with primary key EmpNo, and a DEPENDENTS table with a foreign key. Referential integrity can be used to ensure child records are not inserted without a valid parent. |
| Primary Key | The column or columns used to uniquely identify every row in a table. |
| Query | A question. A database operation that retrieves data from a database. |
| Referential Integrity | Refers to the integrity of the foreign key references in a database. All foreign keys should refer to valid primary keys in other tables. |
| Relationship | An association between two or more entities such as that between DEPARTMENTS and EMPLOYEES. |
| SQL | Virtually all relational databases store and retrieve data via this coding. |
| Validation Rule | A rule used to enforce domain integrity. I.e to ensure column values are valid. Examples: make sure all amounts are positive, dates are greater than or equal to today, etc. |
| Relational Database | A database with multiple related tables |
| Flat file Database | A database with a single table |
| Table | All the records associated with an entity, eg customer |
| Record | All the information about one person or thing |
| Form | A view of a database to input or view (usually) one record. Also used to enable navigation and a user interface |
