In the world of computing, managing data is a critical task. For small to medium businesses, this usually means using some form of database. A database is a collection of data that is organized in a specific way. In order to manage this data, you need to be able to access it and manipulate it using special commands.
This article will introduce you to the basics of SQL commands.
What is SQL?
SQL, or Structured Query Language, is a language used to communicate with databases. It allows you to access and modify the data within a database in various ways. SQL commands are typically entered into a text editor such as Notepad or sublime text and then run from there.
Where do I find a list of SQL commands?
There are many different sources for lists of SQL commands. A good place to start is the Microsoft website:
SQL Commands for Beginners:
SELECT
The SELECT command is used to select data from a database table. It takes the following form:
SELECT column1, column2, FROM table_name
For example, the following query would return all of the data from the “Products” table:
SELECT * FROM Products
INSERT
The INSERT command is used to add new data to a database table. It takes the following form:
INSERT INTO table_name (column1, column2,) VALUES (value1, value2,)
For example, the following query would add a new product to the “Products” table:
INSERT INTO Products (ProductName, UnitPrice) VALUES (‘New Product’, 25.99)
UPDATE
The UPDATE command is used to update data in a database table. It takes the following form:
UPDATE table_name SET column1 = value1, column2 = value2, WHERE condition
For example, the following query would update the price for the “New Product” product to 26.99:
UPDATE Products SET UnitPrice = 26.99 WHERE ProductName = ‘New Product’
DELETE
The DELETE command is used to delete data from a database table. It takes the following form:
DELETE FROM table_name WHERE condition
For example, the following query would delete the “New Product” product from the “Products” table:
DELETE FROM Products WHERE ProductName = ‘New Product’
SQL commands provide a way to manage and access data in databases. In this article, we have introduced you to some of the most common SQL commands. To know more check RemoteDBA.com.
FAQs:
Q: What is a database?
A: A database is a collection of data that is organized in a specific way.
Q: What is SQL?
A: SQL, or Structured Query Language, is a language used to communicate with databases. It allows you to access and modify the data within a database in various ways.
Q: What are some common SQL commands?
A: SELECT, INSERT, UPDATE, AND DELETE. These are some of the most common SQL commands. There are many others, and you can find a more comprehensive list online.
Q: How do I run SQL commands?
A: You can run SQL commands by entering them into a text editor such as Notepad or sublime text and then running them from there.
Q: What is the difference between SELECT and VIEW?
A: SELECT is used to select data from a database table, while VIEW is used to create a virtual table made up of data from one or more other tables.
Q: What is the difference between an UPDATE and a REPLACE statement?
A: An UPDATE statement updates data in a database table, while a REPLACE statement replaces all of the data in a database table.
Q: What is the difference between a DELETE and a TRUNCATE statement?
A: A DELETE statement deletes data from a database table, while a TRUNCATE statement deletes all of the data in a database table and removes the table from the database.
Q: What is a primary key?
A: A primary key is a column (or set of columns) in a database table that is used to uniquely identify each row in the table.
Q: What is a foreign key?
A: A foreign key is a column (or set of columns) in a database table that references the primary key of another table. This allows data to be linked between tables.
Conclusion:
SQL commands provide a way to manage and access data in databases. In this article, we have introduced you to some of the most common SQL commands. For a more comprehensive list, please see a resource online such as Microsoft’s website.
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