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Whether you’re just starting out in data science or looking to broaden your skillset in software development, learning SQL is absolutely essential. SQL (Structured Query Language) is the standard language used to communicate with databases, extract and manipulate data. This blog post aims to cover the basics of SQL, focusing on data manipulation – an integral part of every data professional’s skillset.
What is SQL?
In simple terms, SQL is the primary language used to examine and manipulate databases. It allows you to interact with the data in a highly efficient manner, using commands to perform different functions ranging from data querying, to manipulation and aggregation.
SQL COMMANDS
Let’s dive into the most common SQL commands and how they are used.
1. SELECT
A SELECT statement is used to select data from a database. The data returned is stored in a result table, also called the result-set.
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/* Here is an example of a simple SELECT statement */ SELECT column_name FROM table_name |
2. INSERT INTO
The INSERT INTO statement is used to insert new records in a table.
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/* Here is how you would add a new record */ INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...); |
3. UPDATE
UPDATE is a command used to update existing records in a table.
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/* Here is how you would update a record */ UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; |
4. DELETE
DELETE is a command used to delete existing records in a table. Be careful with this command; once data is deleted, it cannot be recovered.
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/* Here is how you would delete a record */ DELETE FROM table_name WHERE condition; |
In conclusion, SQL is a powerful tool for managing and manipulating databases. While we’ve only touched the base here, these basic commands are the building blocks for any database manipulation. Understanding these commands is your first step in gaining SQL proficiency. Happy querying!
References:
For additional references, you can explore the following resources: