QUIZ TUTORIAL: SQL QUERIES

What does SQL stand for?

• Structured Language Query

• Standardized Query Language

• Structured Query Language

• Sequential Query Language

Answer explanation

SQL stands for Structured Query Language, and it is a standard programming language designed for managing and manipulating relational databases.

What is the purpose of the SQL GROUP BY clause?

• Sorting the result set

• Filtering the result set

• Grouping rows that have the same values in specified columns

• Joining multiple tables

Answer explanation

The GROUP BY clause in SQL is used to group rows that have the same values in specified columns into summary rows, like "total" or "average."

Which SQL clause is used to filter the results of a query based on a specified condition?

• SELECT

• FROM

• WHERE

• GROUP BY

Answer explanation

The WHERE clause in SQL is used to filter the results of a query based on a specified condition. It allows you to retrieve data that meets certain criteria.

Which SQL statement is used to update existing records in a table?

• INSERT INTO

• MODIFY

• UPDATE

• ALTER TABLE

Answer explanation

The UPDATE statement in SQL is used to modify the existing records in a table. It allows you to change the values of one or more columns in a specified table.

In SQL, what does the term "JOIN" refer to?

• Combining two or more tables based on related columns

• Filtering rows based on a condition

• Ordering the result set

• Creating a new table

Answer explanation

The JOIN operation in SQL is used to combine rows from two or more tables based on a related column between them.

Which SQL command is used to remove a table from the database?

• DELETE TABLE

• DROP TABLE

• REMOVE TABLE

• ERASE TABLE

Answer explanation

The DROP TABLE command in SQL is used to remove a table and its data permanently from the database.

What is the purpose of the SQL ORDER BY clause?

• Filtering the result set

• Sorting the result set

• Grouping rows

• Joining multiple tables

Answer explanation

The ORDER BY clause in SQL is used to sort the result set of a query in ascending or descending order based on one or more columns.

Which SQL function is used to find the total number of rows in a table?

• TOTAL()

• COUNT()

• SUM()

• AVG()

Answer explanation

The COUNT() function in SQL is used to find the total number of rows in a table.

What does the SQL term "NULL" represent?

• Empty string

• Zero

• Missing or undefined data

• Infinity

  
  

Answer explanation

In SQL, the term "NULL" represents a missing or undefined value in a column. It is not the same as an empty string or zero.

Which SQL statement is used to add new records to a table?

• ADD RECORD

• INSERT INTO

• CREATE RECORD

• APPEND TO

Answer explanation

The INSERT INTO statement in SQL is used to add new records (rows) to a table. It allows you to specify the values for each column or select values from another table.