What types of relationships are possible in a relational database? Describe and give an example of each.
What types of relationships are possible in a relational database? Describe and give an example of each.
发布时间：2024-11-18 06:40:26
请在 下方输入 要搜索的题目：
推荐参考答案 (
由 快搜搜题库 官方老师解答 )
答案：There are three types of relationships: one-to-one, one-to-many, and many-to-many. A one-to-one relationship occurs when each record in one table has only one related record in a second table. An example might be a table of salespeople and a separate table of company cars. Each salesperson can only have one car, or be related to the one car in the database. A one-to-many relationship occurs when a record in one table has many related records in a second table. An example might be a table of salespeople and clients. Each salesperson may have several clients. A many-to-many relationship occurs when records in one table have many related records in a second table, and the records in the second table have many related records in the first table. An example might be a clients table and a products table. Clients may buy more than one product, and products are sold to more than one client.
相关试题
- 1.What types of relationships are possible in a relational database?
- 2.What mathematical concept is a relational database model based on?
- 3.What is each row in a relational database table called?
- 4.Explain the two main causes of market failure and give an example of each.
- 5.An example of a pre-digital database is a:
- 6.What example does not belong to the three types of examples in speechmaking?
- 7.Give an example of a Mayday call.
- 8.Can you tell me what wild goose chase is ? Give me an example of it.
- 9.We could use to describe the possible advantages of organic food.
- 10.What type of database is PubMed?
