Querying Data with Transact-SQL Part 2

1. Introduction to Transact-SQL

In this module you will learn about the basics of the Transact-SQL (T-SQL) language, as well as general properties and terminology of relational databases. This module will also introduce the basic SELECT statement for retrieving data from a table. After completing this module, you’ll be able to:

• Understand what SQL is for
• Identify database objects in schemas
• Identify SQL statement types
• Use the SELECT statement
• Work with data types
• Handle NULLs

2. Sort and filter results in T-SQL

In the module you will learn how to control what data is returned, the order in which it is returned. You will use the ORDER BY clause, with and without paging. You will learn about various kinds of filters that can be used in the WHERE clause to control which data rows are returned. You will also learn how to manage the results by removing duplicates with DISTINCT. After completing this module, you will be able to:

• Sort your results
• Limit the sorted results
• Return paged results
• Remove duplicates
• Filter data with predicates

3. Combine multiple tables with JOINs in T-SQL

In this module, you will explore T-SQL queries which access data from multiple tables with various kinds of JOIN operations and simple subqueries. After completing this module, you will be able to:

• Describe join concepts and syntax
• Write queries that use inner and outer joins
• Write queries that use cross joins
• Write queries that use self joins

4. Write Subqueries in T-SQL

After completing this module, you will be able to:

• Understand what subqueries are
• Use scalar or multi-valued subqueries
• Use self-contained or correlated subqueries

5. Use built-in functions and GROUP BY in Transact-SQL

In the module you will explore the use of built-in functions for returning computed or special values in the SELECT list or in the WHERE clause. Functions include math functions, string functions and system functions. There are other types of functions that will be mentioned, but not discussed in detail. You will also learn how to combine rows of data into a single group, providing summary information for the group such as SUM, MIN or MAX.

After completing this module, you will be able to:

• Categorize built-in functions
• Use scalar functions
• Use ranking and rowset functions
• Use aggregate functions
• Summarize data with GROUP BY
• Filter groups with HAVING

6. Modify data with T-SQL

In this module, you will learn the T-SQL statements for modifying table data including UPDATE, DELETE and MERGE as well as various options for INSERT including creating a new table with data from an existing table. You will also look at how to have the system automatically supply values for columns as the data is inserted. After completing this module, you will be able to:

• Insert data into a table
• Generate automatic values
• Update data in a table
• Delete data from a table
• Merge data based on multiple tables