Database Access Tutorials

Introduction to Database Access

This tutorial will guide you through the fundamental concepts of accessing and manipulating data in a relational database. We'll start with basic data retrieval and simple update operations.

Data Retrieval - SELECT

The SELECT statement allows you to retrieve specific data from a table. Let's see an example:

                    SELECT *
                    FROM Customers
                    WHERE Country = 'USA';
                

This query retrieves all columns and rows from the 'Customers' table where the 'Country' column is equal to 'USA'.

Data Update - UPDATE

The UPDATE statement modifies existing data. Let's update the 'Age' of a customer:

                    UPDATE Customers
                    SET Age = 30
                    WHERE Country = 'USA';
                

This update sets the 'Age' of the customer with the Country 'USA' to 30.

Data Display - LIMIT

The LIMIT clause limits the number of rows returned. Let's get the first 5 customers:

                    SELECT *
                    FROM Customers
                    LIMIT 5;
                

This returns only the first 5 customers.

More Data

Here's another example: SELECT * from Orders WHERE OrderDate > '2023-01-01';

Conclusion

This is a basic introduction to database access. Further learning involves advanced techniques like joins, aggregations, and stored procedures.