Database Relationships - Wikitechy https://www.wikitechy.com/interview-questions/tag/database-relationships/ Interview Questions Tue, 27 Sep 2022 05:48:21 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 https://www.wikitechy.com/interview-questions/wp-content/uploads/2025/10/cropped-wikitechy-icon-32x32.png Database Relationships - Wikitechy https://www.wikitechy.com/interview-questions/tag/database-relationships/ 32 32 What are the different types of relationships in SQL ? https://www.wikitechy.com/interview-questions/sql/what-are-the-different-types-of-relationships-in-sql/ https://www.wikitechy.com/interview-questions/sql/what-are-the-different-types-of-relationships-in-sql/#respond Tue, 27 Sep 2022 05:48:21 +0000 https://www.wikitechy.com/interview-questions/?p=4856
  • Data base collects different types of data that uses tables, record, and columns.
  • For easy storage of data, a well-defined relationship is created between tables and databases.
  • Data in a table is based on a relational model.
  • A unique Id and the key is created for each row.
  • Data attributes are held in the column of the table.

    • Different Types of Relational DataBase Tables

    One to One Relationship

    • This relationship helps to create a relationship between tables where a single row of the first table can only be related to one and only one record of the second row.
    • The same way one record of the second table can be related to one and only one record of the first table.

    One to many Relationship

    • This helps to create a relationship between the two tables.
    • Any single row of a table can be connected to one or more rows in a second table.
    • Rows from the second table can relate to only one row in the first table. This relationship is known as one to many relationship.

    Many to Many Relationship

    • Here relationship is created between two tables.
    • Each record in the first table can be related to many records in the second table.
    • Similarly, each record from the second row can relate to any records in the first row.
    • It is represented as N: N.

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