Demystifying the Database: SQL for Web Developers

Demystifying the Database: SQL for Web Developers image

FAQ

What is SQL?

SQL stands for Structured Query Language and it is used to communicate with databases to manage, manipulate, and retrieve data.

What is a database?

A database is an organized collection of data, typically stored and accessed electronically from a computer system.

What are some common SQL commands?

Some common SQL commands include SELECT, INSERT, UPDATE, DELETE, CREATE, and DROP.

How do you retrieve data from a database using SQL?

You can retrieve data from a database using the SELECT statement followed by the columns you want to retrieve and the table you want to retrieve it from.

What is a primary key in SQL?

A primary key is a unique identifier for a record in a database table. It ensures that each record can be uniquely identified.

How do you filter data in SQL?

You can filter data using the WHERE clause in SQL, which allows you to specify conditions that must be met for a record to be included in the result set.

What is a foreign key in SQL?

A foreign key is a column or a combination of columns that is used to establish and enforce a link between data in two tables.

How do you join tables in SQL?

You can join tables in SQL using the JOIN clause, which allows you to combine rows from two or more tables based on a related column between them.

How do you perform calculations in SQL?

You can perform calculations in SQL using mathematical operators like +, -, *, and / within your SELECT statement or other SQL commands.

Can you update multiple rows at once in SQL?

Yes, you can update multiple rows at once in SQL using the UPDATE statement with a WHERE clause to specify the rows you want to update based on certain conditions.
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