Mastering SQL Queries

What does SQL stand for?

• Simple Query Language

• Structured Query Language

• Structured Query List

• Standard Query Language

Which SQL statement is used to retrieve data from a database?

• SELECT

• DELETE

• INSERT

• UPDATE

How do you insert a new record into a table in SQL?

• UPDATE table_name SET column1 = value1 WHERE condition;

• DELETE FROM table_name WHERE condition;

• SELECT * FROM table_name;

• INSERT INTO table_name (column1, column2) VALUES (value1, value2);

What is the purpose of the WHERE clause in SQL?

• To create new database records.

• To filter records based on specified conditions.

• To sort records in ascending order.

• To join multiple tables together.

How can you update existing records in a SQL table?

• Utilize the SQL INSERT statement to add new records.

• Use the SQL SELECT statement to retrieve records.

• Use the SQL UPDATE statement with SET and WHERE clauses.

• Apply the SQL DELETE statement to remove records.

What SQL command is used to delete records from a table?

• CLEAR

• REMOVE

• DROP

• DELETE

What is a primary key in a database?

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

• A primary key is a type of foreign key.

• A primary key can be duplicated across records.

• A primary key is an optional field in a database.

Explain the difference between INNER JOIN and LEFT JOIN.

• INNER JOIN returns all rows from both tables; LEFT JOIN returns only unmatched rows from the left.

• INNER JOIN returns all rows from the right table; LEFT JOIN returns only matched rows from the left.

• INNER JOIN returns matched rows only; LEFT JOIN returns all rows from the left table and matched rows from the right.

• INNER JOIN includes unmatched rows from the left table; LEFT JOIN excludes unmatched rows from both tables.

What is the function of the GROUP BY clause in SQL?

• To create new tables from existing data.

• To group rows that have the same values in specified columns and perform aggregate calculations on them.

• To sort rows in ascending or descending order.

• To filter rows based on a specific condition.

How do you sort the results of a query in SQL?

• Results are automatically sorted by default.

• Use the ORDER BY clause in your SQL query.

• Use the GROUP BY clause to sort results.

• Sort results by using the SELECT statement.