Transact-SQL

Local variables begin with an at sign (@) and are declared using DECLARE. A newly declared variable has the value NULL. Values can be assigned using SET or SELECT, although Microsoft recommends SET for variable assignment.^[5]

Control-flow constructs include BEGIN...END, IF...ELSE, WHILE, BREAK, CONTINUE, RETURN, GOTO, WAITFOR, THROW, and TRY...CATCH.^[6]

Stored procedures can accept input parameters, return values through output parameters, contain statements that operate on a database, and return a status value to their caller.^[7]

The TRY...CATCH construct transfers control to a CATCH block when certain execution errors occur inside its associated TRY block.^[8]

Transact-SQL extends the DELETE statement with an additional FROM clause, allowing rows to be identified using joined table sources.^[9] Its UPDATE statement also accepts a FROM clause containing table, view, or derived-table sources used to determine which rows are updated.^[10]

The BULK INSERT statement imports data from a file into a table or view. Depending on the Microsoft database product, the source can be a file accessible to the server or a file in Azure Storage.^[11]