Basics like Database Record Primary Key Field data types and MS Access Interface

Understanding Tables in a Database

A table is a fundamental element of a database, designed to store data related to a specific topic, such as employees or products. It is composed of records and fields.

• Records: Each record represents a single instance of the subject, like a specific employee. Records are often referred to as rows.
• Fields: Fields hold data about one aspect of the subject, such as an employee's first name or email address. Fields are commonly known as columns.

A record is made up of field values, which are the specific data points, such as "John Doe" or "[email protected]."

Multiple Tables in a Database

A database typically contains multiple tables, each storing information on different subjects. These tables can include various data types such as text, numbers, dates, and hyperlinks.

External Data Sources

Databases like Microsoft Access can link to external data sources, including other databases, text files, and Excel workbooks. When linked, this external data can be treated as if it were a table within Access, allowing you to edit the data and create relationships with it. However, the design of the external data cannot be altered through Access.

Properties of Tables and Fields

Tables and fields come with properties that can be customized to control their behavior.

• Table Properties: These attributes impact the overall appearance or behavior of the table and are set in the table's property sheet.
• Field Properties: These define characteristics of individual fields and can be set in both Datasheet and Design views.

Data Types

Each field in a table has a data type, indicating the type of data it stores, such as text, numbers, or dates. The data type of a field determines its other properties and must be defined when the field is created.

Relationships Between Tables

Tables in a database often contain data that is related. For example, you might have a customers table, a products table, and an orders table. To connect these tables, you create relationships based on common fields, known as keys.

• Primary Key: A unique identifier for each record in a table, such as a customer ID.
• Foreign Key: A field in one table that links to the primary key in another table, establishing a relationship between the two tables.

Benefits of Relationships

Creating relationships between tables ensures consistency, efficiency, and clarity. By storing data about different subjects in separate tables and linking them through relationships, you reduce redundancy and improve the database's overall performance.

Relational Databases

Access is a relational database system, meaning it stores data in separate tables by subject, but the data can be related and combined as needed. This setup allows for flexible data management, making it easier to organize, retrieve, and report on information.

Database Objects

Databases in Access consist of various objects, including:

• Tables: Store data in rows and columns.
  
• Queries: Retrieve and manipulate data.
• Forms: Control data entry and display.
• Reports: Summarize and present data.

Understanding these objects and how to structure tables effectively is crucial for making the most of your database.