INSERT, SELECT, UPDATE, DELETE, and CRUD Foundations
Master everyday T-SQL CRUD operations and understand how application actions map to SQL Server queries.
Inside this chapter
- CRUD as the Daily Work of Applications
- Creating and Reading Data
- Updating and Deleting Carefully
- Capturing Inserted Values
Series navigation
Study the chapters in sequence for the smoothest path from SQL Server basics to advanced T-SQL, performance, and production operations. Use the navigation at the bottom of each page to move through the full tutorial series.
CRUD as the Daily Work of Applications
Most business software repeatedly creates records, reads data into screens and APIs, updates state based on user actions, and deletes or archives outdated information. These create, read, update, and delete operations form the core of most database-driven systems.
Creating and Reading Data
INSERT INTO dbo.Customers (FullName, Email)
VALUES ('Rahul Mehta', 'rahul@example.com');
SELECT CustomerId, FullName, Email
FROM dbo.Customers;Beginners should notice that SQL queries can be explicit and readable. Choosing only the needed columns is a better practice than always selecting every field.
Updating and Deleting Carefully
UPDATE dbo.Customers
SET FullName = 'Rahul S. Mehta'
WHERE CustomerId = 1;
DELETE FROM dbo.Customers
WHERE CustomerId = 99;UPDATE or DELETE without carefully reviewing the WHERE clause. Missing filters can affect every row in a table.
Capturing Inserted Values
INSERT INTO dbo.Products (Sku, ProductName, UnitPrice)
OUTPUT INSERTED.ProductId, INSERTED.ProductName
VALUES ('BK-501', 'SQL Server Guide', 899.00);The OUTPUT clause is useful in SQL Server when applications need generated values immediately after inserts, updates, or deletes.