SQL Easy Test

Which SQL keyword is used to retrieve data from a table?

• GET
• FETCH
• SELECT
• TAKE
• READ

Answer explanation

`SELECT` is the standard SQL keyword for retrieving data.

What is the correct syntax to rename a column in the result set?

• SELECT name RENAME full_name FROM students;
• SELECT name AS full_name FROM students;
• SELECT name TO full_name FROM students;
• SELECT full_name = name FROM students;
• SELECT name IS full_name FROM students;

Answer explanation

`AS` is used to provide an alias for a column.

Which of the following is correct to delete all rows from the table `orders`?

• DELETE ALL FROM orders;
• REMOVE * FROM orders;
• DELETE FROM orders;
• CLEAR TABLE orders;
• DROP ALL FROM orders;

Answer explanation

`DELETE FROM table_name;` removes all rows but keeps the table structure.

Identify the syntax error: `SELECT id name FROM employees;`

• Missing semicolon
• FROM must come before SELECT
• Missing comma between column names
• AS keyword required
• Incorrect table name

Answer explanation

Multiple columns in SELECT must be separated by commas.

What will this query return? `SELECT UPPER('sql');`

• sql
• SQL
• Sql
• 'SQL'
• Error

Answer explanation

`UPPER()` converts the string to uppercase, returning `SQL`.

Which statement creates a new table named `books` with two columns: id (INT) and title (VARCHAR)?

• CREATE TABLE books (id INT, title VARCHAR(100));
• CREATE books TABLE (id INTEGER, title STRING(100));
• NEW TABLE books (id INT, title VARCHAR(100));
• MAKE TABLE books (id INT, title VARCHAR(100));
• CREATE TABLE books (id NUMBER, title TEXT(100));

Answer explanation

Correct SQL syntax uses `CREATE TABLE` followed by column definitions.

Which SQL keyword is used to sort the result set?

• SORT BY
• ORDER
• ARRANGE BY
• ORDER BY
• SORT

Answer explanation

`ORDER BY` is the SQL keyword for sorting.

Identify the correct UPDATE syntax to change the `price` of all products to 100.

• UPDATE products SET price = 100;
• UPDATE price = 100 FROM products;
• CHANGE products.price TO 100;
• UPDATE products TO price = 100;
• SET products.price = 100;

Answer explanation

The correct syntax is `UPDATE <table> SET <column>=<value>;`.

What is wrong with this query: `SELECT * students;`

• Missing table name after FROM
• Missing WHERE clause
• Missing column list
• FROM must be before table name
• Incorrect keyword SELECT

Answer explanation

The correct syntax is `SELECT * FROM students;`.

What will this query output? `SELECT LENGTH('Hello');`

• 4
• 5
• 'Hello'
• LENGTH
• Error

Answer explanation

`LENGTH('Hello')` returns 5 because the string has 5 characters.