How many types of constraints are present in SQL Server?

Question

A) 4

B) 5

C) 6

D) 7

Answer 1

In SQL Server, there are generally six types of constraints that can be used to enforce data integrity rules. Therefore, the correct answer is:

C) 6

Answer 2

The correct answer to the question “How many types of constraints are present in SQL Server” is option ©. 6. Types of constraints present in SQL Server are Not Null Constraint, Check constraint, Default Constraint, Unique Constraint, Primary Constraint, and Foreign Constraint. Wish to learn SQL and get certified? Enroll in a good SQL course from Intellipaat. And watch the following video on SQL Interview Questions and Answers from domain experts.

Answer 3

In SQL Server, there are generally six types of constraints that can be applied to database tables. These constraints are used to enforce rules and maintain data integrity within the database. The answer is C) 6.

Answer 4

In SQL Server, there are typically six types of constraints that can be used to enforce data integrity rules. These constraints are as follows:

1. Primary Key Constraint: Ensures that each value in a column or a combination of columns is unique and not null. It is used to identify each row uniquely in a table.

   

2. Unique Constraint: Ensures that each value in a column or a combination of columns is unique. Unlike the primary key constraint, it allows null values (except for columns included in the constraint).

3. Foreign Key Constraint: Establishes a relationship between two tables by enforcing referential integrity. It ensures that values in a column (foreign key) of one table match the values in a primary key column (referenced key) of another table.

4. Check Constraint: Enforces that the values in a column meet specific conditions or expressions. It allows you to define custom rules to restrict the values stored in a column.

5. Default Constraint: Sets a default value for a column when no value is specified during an INSERT operation.

6. Not Null Constraint: Ensures that a column does not contain null values. It requires a value to be provided for the column during an INSERT operation.

Therefore, the correct answer is C) 6.