Learn T-SQL Querying

Ad hoc plan caching

An ad hoc query is a T-SQL query that is sent to the server as a block of text with no parameter markers or other constructs. They are typically built on the fly, such as a query that is typed into a query window in SQL Server Management Studio (SSMS) and executed, or one that is sent to the server using the EXECUTE command as in the following code example which can be executed in the AdventureWorks sample database:

EXECUTE (N'SELECT LastName, FirstName, MiddleName FROM Person.Person WHERE PersonType = N''EM'';')

The letter N preceding a string in a T-SQL script indicates that the string should be interpreted as Unicode with UTF-16 encoding. In order to avoid implicit data-type conversions, be sure to specify N for all ...