原文:发现SQL Server惊天大秘密！！
--set statistics xml onCREATE TABLE T_TEST(ID INT IDENTITY PRIMARY KEY,CreateTime DATE)INSERT INTO T_TEST SELECT '2011-11-04'UNION ALL SELECT '2011-11-04'UNION ALL SELECT '2011-11-04'UNION ALL SELECT '2011-11-05'UNION ALL SELECT '2011-11-05'UNION ALL SELECT '2011-11-05'SELECT * FROM T_TESTSELECT COUNT(*) FROM T_TEST WHERE CreateTime>='2011-11-04 00:00:00' AND CreateTime <='2011-11-04 23:59:59'--等价于(返回3行，这个没有问题)SELECT COUNT(*) FROM T_TEST WHERE CreateTime='2011-11-04'SELECT COUNT(*) FROM T_TEST WHERE CreateTime>='2011-11-04 00:00:00' AND CreateTime <'2011-11-04 23:59:59'--等价于(返回0行，因为where条件无意义，这个也没有问题)SELECT COUNT(*) FROM T_TEST WHERE CreateTime>='2011-11-04' AND CreateTime <'2011-11-04'--传入参数为datetime类型(它为什么能返回3行？!!!!这是为什么！！)SP_executesql N' select COUNT(*) from T_TEST where CreateTime>=@BeginTime and CreateTime<@EndTime',N'@BeginTime datetime,@EndTime datetime',@BeginTime='2011-11-04 00:00:00',@EndTime='2011-11-04 23:59:59' --修改了传参类型为date类型(返回0行)SP_executesql N' select COUNT(*) from T_TEST where CreateTime>=@BeginTime and CreateTime<@EndTime',N'@BeginTime date,@EndTime date',@BeginTime='2011-11-04 00:00:00',@EndTime='2011-11-04 23:59:59'