Other unique or unusual features of Transact-SQL include:
The following extensions to SQL search conditions: modulo operator (%), negative comparison operators (!>, !<, and !=), bitwise operators (–, ^, |, and &), join operators (*= and =*), wildcard characters ([ ] and -), and the not operator (^). See Chapter 2, “Queries: Selecting Data from a Table.”
Fewer restrictions on the group by clause and the order by clause. See Chapter 3, “Using Aggregates, Grouping, and Sorting.”
Subqueries, which can be used almost anywhere an expression is allowed. See Chapter 5, “Subqueries: Using Queries Within Other Queries.”
Temporary tables and other temporary database objects, which exist only for the duration of the current work session, and disappear thereafter. See Chapter 7, “Creating Databases and Tables.”
User-defined datatypes built on Adaptive Server-supplied datatypes. See Chapter 6, “Using and Creating Datatypes,” and Chapter 14, “Defining Defaults and Rules for Data.”
The ability to insert data from a table into that same table. See Chapter 8, “Adding, Changing, Transferring, and Deleting Data.”
The ability to extract data from one table and put it into another with the update command. See Chapter 8, “Adding, Changing, Transferring, and Deleting Data.”
The ability to remove data based on data in other tables using the join in a delete statement. See Chapter 8, “Adding, Changing, Transferring, and Deleting Data.”
A fast way to delete all rows in a specified table and reclaim the space they took up with the truncate table command. See Chapter 8, “Adding, Changing, Transferring, and Deleting Data.”
Identity columns, which provide system-generated values that uniquely identify each row within a table. See Chapter 8, “Adding, Changing, Transferring, and Deleting Data.”
Updates and selections through views. Unlike most other versions of SQL, Transact-SQL places no restrictions on retrieving data through views, and few restrictions on updating data through views. See Chapter 12, “Views: Limiting Access to Data.”
Dozens of built-in functions. See Chapter 16, “Using the Built-In Functions in Queries.”
Options to the create index command for fine-tuning aspects of performance determined by indexes, and controlling the treatment of duplicate keys and rows. See Chapter 13, “Creating Indexes on Tables.”
Control over what happens when a user attempts to enter duplicate keys in a unique index, or duplicate rows in a table. See Chapter 13, “Creating Indexes on Tables.”
Bitwise operators for use with integer and bit type columns. See “Bitwise operators” and Chapter 6, “Using and Creating Datatypes.”
Support for text and image datatypes. See Chapter 6, “Using and Creating Datatypes.”
The ability to gain access to both Sybase and non-Sybase databases. With Component Integration Services, you can accomplish the following types of actions between tables in remote, heterogeneous servers: access remote tables as if they were local, perform joins, transfer data between tables, maintain referential integrity, provide applications such as PowerBuilder® with transparent access to heterogeneous data, and use native remote server capabilities. For more information, see the Component Integration Services User’s Guide.
