摘要:
NULL,表示不明确、未知的列值测试表:testnull(id varchar(32))数据库:Sybase ASA11.0行数据(''), (NULL)数据库选项ansinull为true(也是ASA数据库的默认选项)时,select * from testnull where id = nullselect * from testnull where id != null结果均为空select * from testnull where idis null结果为(NULL)select * from testnull where idis notnull结果为('& 阅读全文