Mastering SQL and Normalization

What does SQL stand for?

• Simple Query Language

• Structured Query Language

• Structured Query List

• Standard Query Language

Which of the following is a SQL command?

• INSERT

• DELETE

• SELECT

• UPDATE

What is the purpose of the SELECT statement in SQL?

• To update existing records in a database.

• To create a new database table.

• To retrieve data from a database.

• To delete data from a database.

Define a primary key in a database.

• A primary key is used to store large binary data in a database.

• A primary key is a type of foreign key in a database.

• A primary key is a unique identifier for a record in a database table.

• A primary key can contain duplicate values in a table.

What is a foreign key?

• A foreign key is a field in a database table that creates a link between two tables.

• A foreign key is a field that stores images in a database.

• A foreign key is a unique identifier for a table.

• A foreign key is a type of primary key.

Explain the concept of normalization in databases.

• Normalization is the process of combining all data into a single table.

• Normalization is only concerned with data security and access control.

• Normalization in databases is the process of structuring data to minimize redundancy and dependency by organizing it into tables and establishing relationships.

• Normalization eliminates the need for relationships between tables.

What is the first normal form (1NF)?

• A database table is in first normal form (1NF) if it has no restrictions on data types in columns.

• A database table is in first normal form (1NF) if it can contain duplicate values in a column.

• A database table is in first normal form (1NF) if it allows nested tables within columns.

• A database table is in first normal form (1NF) if it contains only atomic values and each column has unique names.

What is the second normal form (2NF)?

• A table is in Third Normal Form (3NF) if it has no transitive dependencies.

• A table is in Second Normal Form (2NF) if it is in First Normal Form (1NF) and all non-key attributes are fully functionally dependent on the primary key.

• A table is in Second Normal Form (2NF) if it contains no duplicate rows.

• A table is in Second Normal Form (2NF) if it has a composite primary key.

What is the third normal form (3NF)?

• A database table is in first normal form (1NF) if it has no repeating groups.

• A database table is in third normal form (3NF) if it contains only numeric data types.

• A database table is in third normal form (3NF) if it has no foreign keys.

• A database table is in third normal form (3NF) if it is in second normal form (2NF) and all the attributes are functionally dependent only on the primary key.

Why is normalization important in database design?

• Normalization is only necessary for large databases.

• Normalization complicates database queries and slows performance.

• Normalization helps eliminate redundancy and maintain data integrity in database design.

• Normalization increases data duplication for faster access.