SQL Basics

What does SQL stand for?

• Structured Query Language

• Structured Query Logic

• System Query Language

• Sequential Query Language

What is the purpose of SQL?

• The purpose of SQL is to develop mobile applications.

• The purpose of SQL is to analyze and visualize data.

• The purpose of SQL is to create and design websites.

• The purpose of SQL is to manage and manipulate relational databases.

What are the different types of SQL statements?

• Select, Insert, Update, Delete

• Create, Alter, Drop, Truncate

• Join, Union, Group By, Having

• DDL, DML, DCL, TCL

What is a database in SQL?

• A random assortment of data.

• A structured collection of data.

• A spreadsheet.

• A programming language.

What is a table in SQL?

• A table in SQL is a collection of related data organized in rows and columns.

• A table in SQL is a file format used to store images and videos.

• A table in SQL is a mathematical calculation used to organize data.

• A table in SQL is a type of furniture used for dining or working.

What is a primary key in SQL?

• A primary key in SQL is a column or a set of columns that uniquely identifies each row in a table.

• A primary key in SQL is a column that is used to calculate the average value of a table.

• A primary key in SQL is a column that is used to store the most important data in a table.

• A primary key in SQL is a column that is used to sort the data in a table.

What is a foreign key in SQL?

• A foreign key is a field that is used to calculate values in a table.

• A foreign key is a field or a combination of fields in a table that is used to establish a link or relationship between two tables.

• A foreign key is a field that is used to sort data in a table.

• A foreign key is a field that is used to store data from another table.

What is the difference between WHERE and HAVING clauses in SQL?

• The WHERE clause is used to filter groups based on a condition, while the HAVING clause is used to filter rows based on a condition.

• The WHERE clause is used to sort rows based on a condition, while the HAVING clause is used to sort groups based on a condition.

• The WHERE clause is used to join tables based on a condition, while the HAVING clause is used to join columns based on a condition.

• The WHERE clause is used to filter rows based on a condition, while the HAVING clause is used to filter groups based on a condition.

What is the difference between INNER JOIN and OUTER JOIN in SQL?

• INNER JOIN returns all the rows from one table and the matching rows from the other table based on the specified condition, while OUTER JOIN returns only the matching rows between two tables based on the specified condition.

• INNER JOIN and OUTER JOIN are the same and can be used interchangeably in SQL.

• INNER JOIN and OUTER JOIN are not valid SQL keywords.

• INNER JOIN returns only the matching rows between two tables based on the specified condition, while OUTER JOIN returns all the rows from one table and the matching rows from the other table based on the specified condition.

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

• The purpose of the GROUP BY clause in SQL is to group rows with the same values in specified columns.

• The GROUP BY clause in SQL is used to filter rows based on a condition.

• The GROUP BY clause in SQL is used to sort the data in ascending order.

• The GROUP BY clause in SQL is used to update values in a table.