SQL Quiz

What is the purpose of the CREATE TABLE command in SQL?

• To create a new table in the database

• To update an existing table in the database

• To delete a table from the database

• To retrieve data from a table in the database

Explain the difference between the ALTER TABLE and DROP TABLE commands in SQL.

• The ALTER TABLE command is used to add a new column to a table, while the DROP TABLE command is used to rename a table.

• The ALTER TABLE command is used to create a new table, while the DROP TABLE command is used to update the data in a table.

• The ALTER TABLE command is used to modify an existing table, while the DROP TABLE command is used to delete an entire table.

• The ALTER TABLE command is used to delete an entire table, while the DROP TABLE command is used to modify an existing table.

How is the CONSTRAINT keyword used in SQL DDL commands?

• It is used to perform arithmetic operations on the data in a table.

• It is used to create a new database in SQL.

• It is used to retrieve data from a table in SQL.

• It is used to define rules or restrictions for the data in a table.

What is the role of the INSERT command in SQL DML?

• To delete existing rows of data from a table

• To create a new table in the database

• To add new rows of data into a table

• To update existing rows of data in a table

Describe the UPDATE command and provide an example of its usage.

• MODIFY table_name SET column1 = value1, column2 = value2 WHERE condition;

• CHANGE table_name SET column1 = value1, column2 = value2 WHERE condition;

• UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;

• UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;

What is the significance of the DELETE command in SQL DML?

• It is used to remove one or more rows from a table.

• It is used to retrieve data from a table

• It is used to create a new table

• It is used to update the data in a table

What is the purpose of the SELECT statement in SQL DQL?

• To insert data into a database

• To delete data from a database

• To update data in a database

• To retrieve data from a database.

Explain the difference between the WHERE and HAVING clauses in SQL.

• The WHERE clause is used for filtering records after the GROUP BY clause, while the HAVING clause is used for filtering records before the GROUP BY clause.

• The WHERE clause is used for filtering text data, while the HAVING clause is used for filtering numeric data.

• The WHERE clause is used to filter records based on a specified condition, while the HAVING clause is used to filter records based on a specified condition after the GROUP BY clause.

• The WHERE clause is used for mathematical operations, while the HAVING clause is used for string operations.

How is the GROUP BY clause used to filter data in SQL?

• It is used to delete duplicate records in the database

• It is used to sort the data in ascending order

• It is used to perform mathematical operations on the data

• It is used to group and filter data based on specified columns.

When would you use the INSERT INTO command in SQL?

• To delete existing records from a table

• To add new records (rows) to a table.

• To update existing records in a table

• To create a new table