Lesson 1

This module discusses queries, cursors and views and SQL Server Database Implementation. MS SQL Server 2016: Queries, Cursors and Views is the second course in the SQL Server 2016 Database Implementation Certification Series. This series is designed to:

1. Provide the technical skills required to implement a database solution on Microsoft’s SQL Server 2016
2. Help you prepare for the Microsoft’s 70-029 Exam, Designing and Implementing Databases with Microsoft SQL Server 2016

In SQL Server 2022, queries, cursors, and views play essential roles in data retrieval, manipulation, and abstraction. Here's a breakdown of each component and its function:
✅ 1. Queries

• Role: Core mechanism for interacting with data
• Purpose: Retrieve, update, insert, or delete data using Transact-SQL (T-SQL).

• SELECT queries are used to read data.
• INSERT, UPDATE, and DELETE queries modify data.
• Can include joins, subqueries, aggregates, and CTEs (Common Table Expressions).
• Can be ad-hoc or stored in stored procedures, views, or functions.

🧠 Example:

SELECT CustomerName, OrderDate
FROM Orders
WHERE OrderDate > '2025-01-01';

✅ 2. Cursors

• Role: Row-by-row processing of query results
• Purpose: Provide a way to iterate through a result set when set-based operations aren’t sufficient.

• Used in complex logic where each row must be handled individually.
• Available types: STATIC, DYNAMIC, FORWARD_ONLY, and KEYSET.
• Can be local/global, and read-only/updatable.

⚠️Note: Cursors are typically slower than set-based operations and should be used sparingly.

DECLARE order_cursor CURSOR FOR
SELECT OrderID FROM Orders;

OPEN order_cursor;
FETCH NEXT FROM order_cursor INTO @OrderID;

WHILE @@FETCH_STATUS = 0
BEGIN
   -- process @OrderID
   FETCH NEXT FROM order_cursor INTO @OrderID;
END;

CLOSE order_cursor;
DEALLOCATE order_cursor;

✅ 3. Views

• Role: Virtual tables representing the result of a query
• Purpose: Simplify complex queries, enforce security, and promote code reuse.

• A view encapsulates a SELECT query and can be queried like a table.
• Can hide joins, filters, or columns from end users.
• Can be updatable under specific conditions.
• Support schema binding (ensures the underlying tables can't be modified in a way that would break the view).

🧠 Example:

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

🧩 How They Work Together in SQL Server 2022

Component	Role in Workflow	Benefits
Queries	Core interaction method	Flexible data access
Views	Abstract and simplify queries	Improve maintainability and security
Cursors	Procedural row-by-row logic	Handle complex, sequential operations

🚀 In SQL Server 2022 Enhancements
T-SQL improvements in SQL Server 2022 enhance query performance.

• Integration with Intelligent Query Processing (IQP) automatically optimizes some query behaviors.
• Views can now better leverage memory grant feedback and adaptive joins when used within complex queries.
• Cursors benefit from improvements in parallel execution and tempdb usage in high-load scenarios.

After completing the course, you will be able to:

1. Write INSERT, DELETE, UPDATE, and SELECT statements that retrieve and modify data
2. Write queries that retrieve and modify data using joins and sub-queries
3. Write queries that summarize data
4. Create views of data
5. Navigate through your table with cursors

As you probably know, you can interact with SQL Server in two ways:

1. by issuing Transact-SQL commands, and
2. by interacting with its GUI, or Graphical User Interface.

This course uses SlideShows and Mouseovers to explain the code syntax used in Transact-SQL commands, and simulations for practicing different elements of the SQL Server GUI.

Queries, Cursors and Views is the second of three courses in the
SQL Server 2016 Database Implementation Certification Series
In the next lesson, the prerequisites for the course will be discussed.