Introduction to Transact SQL

Explore T-SQL querying concepts, compare Microsoft's T-SQL with Oracle and DB, examine ASCII versus Unicode, data types, and how formatting and comments improve readability.

Examine how SQL became an ISO standard in the mid 1980s for interacting with relational databases and how vendors offer dialects to compete.

Format SQL queries for readability by placing each selected column on its own line and using indentation, making missing commas easy to spot. It improves readability when revisiting queries.

Reset the client statistics, run the query, and view the client statistics tab to examine round trips, bytes sent and received, and execution time for performance analysis.

Learn why every SQL statement ends with a semicolon, even when split across lines, and that future SQL releases may require it.

Use print to display messages on screen via standard out, shown in the messages tab and results window. Save or copy outputs with headers to capture row counts and results.

Compare ascii and unicode representations, explain storage differences between one and two bytes, and show when to use ascii for predefined codes like product, zip, and insurance claim codes.

Learn how to handle unicode and ascii in Transact-SQL, using capital N literals to treat strings as unicode, and explore how collation and code pages affect case and accent sensitivity.

Explore the len function and data length to compare characters and bytes in ascii and unicode strings, and decide when to use unicode for non western characters.

Discover how to handle apostrophes in character strings by concatenating with a single quote in Transact-SQL, preventing syntax errors and illustrating ascii and unicode byte counts.

Understand how T-SQL data types define storage for columns, variables, and parameters, from basic to table types, and how implicit and explicit conversions influence queries in management studio.

Compare fixed-length and variable-length character strings using unicode examples, illustrating how nchar pads to twenty-five characters while varchar stores only the actual text, with a hello and world concatenation.

Use variable length character strings for uncertain lengths, such as names and addresses, and fixed length strings for exact lengths like VINs and Social Security numbers to improve efficiency.

Resolve regional ambiguity in date and time by using an ISO format with two characters for year, month, and date to avoid confusion between November 5 and May 11.

Explore date and time functions in Transact-SQL, including date name and date part, plus day, month, year, and hour, showing how these return names or numeric components from a date.

Discover the end-of-month (eom) function, returning the last day of month as a date, by passing a variable, string, column, or number, and shifting to current, previous, or next month.

Explore the table data type by declaring a table variable, defining columns, inserting data, and querying the variable with a where clause cost I.D. is greater than 120.

Explore how null values behave in transact sql comparisons and observe that null is not equal to any value and cannot be reliably compared, yielding unknown or false.

Master SQL Server Management Studio to write and execute queries, explore databases with object explorer, organize scripts in solution explorer, and customize panes with pin, auto-hide, and dock features.

Use a use statement to focus Halton database and run with go, ensuring a semicolon ends statement. Then query other databases with a three-part name (database.schema.table) to avoid losing focus.

Learn to read data from a table using the select statement, choose all columns or specific ones, understand schema dot object notation, and avoid excessive star use for performance.

Use IntelliSense to auto-complete table and column names, reduce typos, and speed up query writing, while hovering to see the schema and confirm the target table.