Best T-SQL Tutorial for Beginners and Advanced Users

T-SQL tutorial searches usually end one of two ways: you find a quick cheat sheet that barely scratches the surface, or you drown in advanced docs assuming you already know everything. Neither helps if what you really want is a clear, step-by-step guide that takes you from writing your first query to building production-ready scripts.

That's exactly what this tutorial delivers.

T-SQL (Transact-SQL) is Microsoft's extension of SQL, powering SQL Server and Azure SQL with features like procedural programming, error handling, variables, and control-flow commands. It goes beyond standard SQL, making it possible to automate workflows, enforce business rules, and optimize performance inside the database itself.

It is the best T-SQL tutorial for:

• Beginners taking their first steps into SQL Server.
• Developers writing application queries.
• DBAs managing large, mission-critical databases.
• Analysts who need efficient, reliable queries for reporting.

This tutorial covers everything, from the fundamental SELECT, INSERT, UPDATE, and DELETE operations to advanced techniques like CTEs, CASE expressions, error handling, and stored procedures. You will not only learn the core T-SQL commands but also how to structure, optimize, and debug queries for real-world use cases.

By the end, you'll have the skills to write, execute, and tune T-SQL queries confidently, with modern tooling like dbForge Edge making the process even faster and smoother.

Let's get started.

What is T-SQL?

T-SQL, short for Transact-SQL, is Microsoft's proprietary extension of the SQL (Structured Query Language) standard. While standard SQL gives you the ability to create tables, query data, and update records, T-SQL goes further by adding procedural programming features that let you control the flow of logic directly inside SQL Server.

Think of it this way: SQL tells the database what data you want, but T-SQL also lets you define how to get it, handle errors along the way, and even automate complex tasks.

Where T-SQL is used

T-SQL is the native language for:

• Microsoft SQL Server: the most widely recognized platform for running T-SQL queries.
• Azure SQL Database & Azure Synapse Analytics: Microsoft's cloud data services that rely on T-SQL for querying, scripting, and data integration.

If you're working with SQL Server in any capacity, whether on-premises or in the cloud, you're already writing and managing T-SQL. Many developers rely on some SQL Server GUI like dbForge Studio for SQL Server or productivity tools such as SQL Complete to make this process faster, cleaner, and more efficient.

As for teams working across different environments, they might find dbForge Edge more suitable as it offers a comprehensive multi-database solution that unifies these capabilities for SQL Server, MySQL, PostgreSQL, and Oracle in a single IDE.

T-SQL vs ANSI SQL

At its core, T-SQL is built on the ANSI SQL standard, so commands like SELECT, INSERT, UPDATE, and DELETE behave the same way. But T-SQL extends this foundation with features that ANSI SQL doesn't define, such as:

• Procedural programming: variables, loops, and conditions (IF…ELSE, WHILE).
• Error handling: structured blocks with TRY…CATCH.
• System functions like @@ERROR and system variables like @@ROWCOUNT for runtime feedback.

Example: ANSI SQL doesn't specify error handling. In T-SQL, you can manage it like this:

BEGIN TRY
    INSERT INTO Employees (Name, Position) 
    VALUES ('Jane Doe', 'Manager');
END TRY
BEGIN CATCH
    PRINT 'An error occurred: ' + ERROR_MESSAGE();
END CATCH;

This ability to gracefully handle runtime issues makes T-SQL indispensable for enterprise applications, where reliability and predictability matter.

In short, T-SQL is SQL, supercharged for SQL Server. It blends the universality of ANSI SQL with Microsoft-specific enhancements to meet the needs of developers, DBAs, and analysts working in real-world environments.

KEYWORD [clause] [options];

SELECT FirstName, LastName
FROM Employees
WHERE Department = 'Sales';

SELECT * FROM Products;
UPDATE Products SET Price = Price * 1.10 WHERE Category = 'Electronics';

SELECT column1, column2
FROM table_name
WHERE condition;

SELECT CustomerID, FirstName, LastName
FROM Customers
WHERE IsActive = 1;

INSERT INTO table_name (column1, column2)
VALUES (value1, value2);

INSERT INTO Employees (FirstName, LastName, Position, HireDate)
VALUES ('Alice', 'Wong', 'Data Analyst', GETDATE());

UPDATE table_name
SET column1 = value1, column2 = value2
WHERE condition;

UPDATE Employees
SET Salary = Salary * 1.05
WHERE Department = 'IT';

DELETE FROM table_name
WHERE condition;

DELETE FROM Products
WHERE Discontinued = 1;

-- Select all active customers
SELECT * FROM Customers WHERE IsActive = 1;

/* Increase all IT department salaries
   by 5% to adjust for inflation */
UPDATE Employees
SET Salary = Salary * 1.05
WHERE Department = 'IT';

DECLARE @totalSales DECIMAL(10,2);

SELECT @totalSales = SUM(Amount)
FROM Sales
WHERE Year = 2025;

SELECT * 
FROM Employees;

SELECT EmployeeID, FirstName, LastName, Department
FROM Employees;

SELECT FirstName, LastName
FROM Employees
WHERE Department = 'Finance';

SELECT ProductName, Price
FROM Products
ORDER BY Price DESC;

SELECT DISTINCT Department
FROM Employees;

SELECT FirstName, LEN(FirstName) AS NameLength
FROM Employees;

SELECT GETDATE() AS CurrentDateTime;

SELECT CAST(Salary AS VARCHAR(20)) AS SalaryText
FROM Employees;

SELECT FirstName, ISNULL(PhoneNumber, 'N/A') AS Phone
FROM Customers;

SELECT FirstName, COALESCE(Mobile, HomePhone, 'N/A') AS ContactNumber
FROM Customers;

SELECT Customers.CustomerID, Customers.FirstName, Orders.OrderID
FROM Customers
INNER JOIN Orders
    ON Customers.CustomerID = Orders.CustomerID;

SELECT Customers.FirstName, Orders.OrderID
FROM Customers
LEFT JOIN Orders
    ON Customers.CustomerID = Orders.CustomerID;

SELECT Customers.FirstName, Orders.OrderID
FROM Customers
RIGHT JOIN Orders
    ON Customers.CustomerID = Orders.CustomerID;

SELECT Customers.FirstName, Orders.OrderID
FROM Customers
FULL OUTER JOIN Orders
    ON Customers.CustomerID = Orders.CustomerID;

SELECT Products.ProductName, Categories.CategoryName
FROM Products
CROSS JOIN Categories;

SELECT E1.EmployeeID, E1.FirstName AS Employee,
       E2.FirstName AS Manager
FROM Employees E1
INNER JOIN Employees E2
    ON E1.ManagerID = E2.EmployeeID;

SELECT SUM(Amount) AS TotalSales
FROM Orders;

SELECT COUNT(CustomerID) AS TotalCustomers
FROM Customers;

SELECT AVG(Salary) AS AvgSalary
FROM Employees
WHERE Department = 'IT';

SELECT MIN(HireDate) AS FirstHire
FROM Employees;

SELECT MAX(Price) AS MostExpensive
FROM Products;

SELECT Department, COUNT(*) AS EmployeesInDept
FROM Employees
GROUP BY Department;

SELECT Department, AVG(Salary) AS AvgSalary
FROM Employees
GROUP BY Department
HAVING AVG(Salary) > 60000;

DECLARE @employeeCount INT;
SET @employeeCount = (SELECT COUNT(*) FROM Employees);
PRINT @employeeCount;

DECLARE @greeting VARCHAR(50);
SET @greeting = 'Hello, T-SQL!';
PRINT @greeting;

DECLARE @today DATE;
SET @today = GETDATE();
PRINT @today;

DECLARE @age INT = 30;

DECLARE @city VARCHAR(100) = 'Lisbon';

DECLARE @startDate DATE = '2025-01-01';

DECLARE @isActive BIT = 1;

DECLARE @pi FLOAT = 3.14159;

SELECT (10 + 5) AS SumResult, (20 % 3) AS Remainder;

SELECT * FROM Employees WHERE Salary >= 50000;

SELECT * FROM Employees
WHERE Department = 'IT' AND IsActive = 1;

SELECT * FROM Products
WHERE (Price > 100 AND Category = 'Electronics') OR Stock < 10;

SELECT FirstName, LastName, Salary
FROM Employees
WHERE Salary > (SELECT AVG(Salary) FROM Employees);

WITH CustomerSales AS (
    SELECT CustomerID, SUM(Amount) AS TotalSales
    FROM Orders
    GROUP BY CustomerID
)
SELECT CustomerID, TotalSales
FROM CustomerSales
WHERE TotalSales > 1000;

CASE 
    WHEN condition THEN result
    [WHEN ...]
    [ELSE result]
END

SELECT FirstName, LastName, 
       CASE 
           WHEN Salary > 80000 THEN 'High'
           WHEN Salary BETWEEN 50000 AND 80000 THEN 'Medium'
           ELSE 'Low'
       END AS SalaryCategory
FROM Employees;

SELECT ProductName, Category, Price
FROM Products
ORDER BY 
    CASE 
        WHEN Category = 'Electronics' THEN 1
        WHEN Category = 'Clothing' THEN 2
        ELSE 3
    END;

BEGIN TRY
    -- risky operations
END TRY
BEGIN CATCH
    -- error handling logic
END CATCH

BEGIN TRY
    BEGIN TRANSACTION;

    UPDATE Accounts
    SET Balance = Balance - 500
    WHERE AccountID = 1;

    UPDATE Accounts
    SET Balance = Balance + 500
    WHERE AccountID = 2;

    COMMIT TRANSACTION;
END TRY
BEGIN CATCH
    ROLLBACK TRANSACTION;
    PRINT 'Error: ' + ERROR_MESSAGE();
END CATCH;

CREATE PROCEDURE GetAllCustomers
AS
BEGIN
    SELECT CustomerID, FirstName, LastName
    FROM Customers;
END;

EXEC GetAllCustomers;

CREATE PROCEDURE GetOrdersByCustomer
    @CustomerID INT
AS
BEGIN
    SELECT OrderID, Amount, OrderDate
    FROM Orders
    WHERE CustomerID = @CustomerID;
END;

EXEC GetOrdersByCustomer @CustomerID = 5;

CREATE FUNCTION GetFullName(@FirstName VARCHAR(50), @LastName VARCHAR(50))
RETURNS VARCHAR(100)
AS
BEGIN
    RETURN @FirstName + ' ' + @LastName;
END;

SELECT dbo.GetFullName(FirstName, LastName) AS FullName
FROM Employees;

CREATE FUNCTION GetHighValueOrders(@MinAmount DECIMAL(10,2))
RETURNS TABLE
AS
RETURN (
    SELECT OrderID, CustomerID, Amount
    FROM Orders
    WHERE Amount > @MinAmount
);

SELECT * FROM dbo.GetHighValueOrders(1000);

CREATE VIEW ActiveCustomers AS
SELECT CustomerID, FirstName, LastName
FROM Customers
WHERE IsActive = 1;

SELECT * FROM ActiveCustomers;

UPDATE ActiveCustomers
SET LastName = 'Johnson'
WHERE CustomerID = 3;

UPDATE Products
SET Price = Price * 1.05
WHERE Category = 'Electronics';

SELECT YEAR(OrderDate) AS Year, MONTH(OrderDate) AS Month,
       SUM(Amount) AS TotalSales
FROM Orders
GROUP BY YEAR(OrderDate), MONTH(OrderDate)
ORDER BY Year, Month;

SELECT CustomerID, Email
FROM Customers
WHERE Email NOT LIKE '%@%.%';

BEGIN TRANSACTION;
    ALTER TABLE Employees ADD MiddleName VARCHAR(50) NULL;
COMMIT TRANSACTION;

CREATE PROCEDURE GetAllCustomers
AS
BEGIN
  SELECT *
  FROM Customers;
END;

EXEC GetAllCustomers;