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A database management system (DBMS) is software designed to create and manage databases. Many different types of database systems exist, each categorised by how they structure and manage data.

Two types of database structure

Databases typically have one of two basic forms:

• single-file or flat file database
• multi-file relational or structured database

A stores data in a plain text file, with each line of text typically representing one record. Fields are separated by delimiters such as commas or tabs. Flat file databases have a simple structure and, unlike relational databases, do not 91香蕉黄色视频 multiple tables and relationships.

A contains multiple tables of data organised in rows and columns that relate to each other through special key fields. These databases are more flexible than flat file structures, and allow for reading, creating, updating, and deleting data. They use Structured Query Language (SQL), a standard programming interface for database interaction.

Types of relationships in a database

In relational database design, there are four types of relationships:

• one to one - one record in a table relates to one record in another table
• one to many - one record in a table relates to multiple records in another table
• many to one - multiple records in one table relate to a single record in another table
• many to many - multiple records in one table relate to multiple records in another table

These relations create functional dependencies within the database. Common examples of relational databases include MySQL, Microsoft SQL Server, and Oracle.

Four types of database management systems

A relational database management is one of four common types of systems you can use to manage your business data. The other three include:

• hierarchical database systems
• network database systems
• object-oriented database systems

A resembles a tree structure, similar to a folder system on a computer. Records have a pre-defined relationships in a one-to-one manner, between 'parent and child' nodes. They require users to navigate the hierarchy to access data. Due to limitations, such databases may be confined to specific uses.

also have a hierarchical structure. However, instead of using a single-parent tree hierarchy, this model 91香蕉黄色视频s many to many relationships, as child tables can have more than one parent.

Finally, in , the information is represented as objects, with different types of relationships possible between objects. Such databases use an object-oriented programming language for development.

NoSQL or non-relational databases

offer a popular alternative to relational databases. They accommodate various forms of unstructured and semi-structured data, including key-value stores, document stores, and graph databases.

Which database is right for you?

Businesses with simple database needs often use standard office tools like spreadsheets. However, if you handle large amounts of data or have complex requirements, consider more robust database systems that offer better functionality. Find tips on choosing the right database for your business.