What is references in MySQL?

Question

The references keyword is used to define which table and column is used in a foreign key relationship. This means that a record in the hobby table must have a person_id that exists in the person table or else at the time of insert you will receive an error that the key does not exist. 3 февр. 2010 г.

What does references mean in SQL?

reference is a database name. In between the database name and the object name goes the schema.

What is foreign key in MySQL?

A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table. The table with the foreign key is called the child table, and the table with the primary key is called the referenced or parent table.

What is referential integrity in MySQL?

Referential integrity is an important concept in database. design. The term refers to a state when all the references in a database are. valid and no invalid links exist between the various tables that make up the. system.

What is constraint in MySQL?

SQL constraints are used to specify rules for the data in a table. Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted.

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