SQL Server Variables

1 Define variables:2 Declare @var_name data_type3 Assignment variables:4 Set Assignment:5     Set@var_num =value #不可多赋值6 Select Assignment Value:7     Select@var_name = value ... fromtable_namewhereunique condition #可多赋值8 Global Variables:9 @ @error The error number of the last SQL errorTen @ @identity The last marked value inserted One @ @language The name of the currently used language A @ @max_connections The maximum number of simultaneous connections that can be created - @ @rowcount The number of rows affected by the previous SQL statement - @ @servername The name of the local server the @ @transcount The number of things open on the current connection -@ @version version information for SQL Server

SQL Server Variables