sql 中@是什么意思

Question

sql 中@是什么意思

Answer 1

对于 SQL Server 来说 @ 用于标示变量名字。例如：1>2>3> DECLARE3 @testvalue AS VARCHAR(20);5> BEGIN3 SET @testvalue = ‘First Test!’;3 PRINT( @testvalue );8> END;9> goFirst Test!对于 Oracle ， @ 可能是标示 链接数据库例如：SQL> CREATE DATABASE LINK mydblink2 CONNECT TO test IDENTIFIED BY test1233 USING '(DESCRIPTION =4 (ADDRESS_LIST =5 (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.210)(PORT = 1521)))6 (CONNECT_DATA = (SERVICE_NAME = orcl)7 )8 )';Database link created.SQL> select count(1) from user_tables@mydblink;COUNT(1)----------6