Candidate KeyĪ candidate key is an attribute or set of attributes that uniquely identifies a record.
SUPER KEY IN DBMS HOW TO
Now we learn about each of these keys and how to use them. The first table is “ Branch Info” and the second table is “ Student_Information”. We take two tables for a better understanding of the key.
To understand these different types of keys better, let's start with database tables. The following is a list of ten different types of keys in DBMS. Types of Keysĭatabases support ten different types of keys in DBMS and each key has different functionality. This post explains the different types of keys in databases, their meanings, and how to set and use these different types of keys in SQL.
Database keys are also used to uniquely identify a row in a database table by a combination of one or more columns in that table.ĭBMS supports multiple types of keys and each of these types has a different purpose and use case. Keys are also used to generate relationships among different database tables or views. A key provides several types of constraints like a column that can’t store duplicate values or null values. In a relational database, data/records are stored in a tabular format, a set of rows and columns. It is used to fetch or retrieve records/data rows from the data table according to the condition/requirement. In other words, a key in DBMS is a column(s) that is used to uniquely identify the record in a table. A key in a database is an attribute on a table column that is used to identify a row or record in a set of rows.
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