1 CREATE TABLE T_TEST(ID INT IDENTITY PRIMARY KEY,CreateTime DATE) 2 INSERT INTO T_TEST SELECT '2011-11-04' 3 UNION ALL SELECT '2011-11-04' 4 UNION ALL SELECT '2011-11-04' 5 UNION ALL SELECT '2011-11-05' 6 UNION ALL SELECT '2011-11-05' 7 UNION ALL SELECT '2011-11-05' 8 9 SELECT * FROM T_TEST 10 11 SELECT COUNT(*) FROM T_TEST 12 WHERE CreateTime>='2011-11-04 00:00:00' AND CreateTime <'2011-11-04 23:59:59' 13 --等价于(返回0行 不太明白????) 14 15 --传入参数为datetime类型(返回3行，这个可以理解，但和上面又有啥区别呢？不解) 16 SP_executesql N' 17 select COUNT(*) 18 from T_TEST 19 where CreateTime>=@BeginTime and CreateTime<@EndTime 20 ',N'@BeginTime datetime,@EndTime datetime', 21 @BeginTime='2011-11-04 00:00:00', 22 @EndTime='2011-11-04 23:59:59' 23 24 --修改了传参类型为date类型(返回0行，这个也可以理解) 25 SP_executesql N' 26 select COUNT(*) 27 from T_TEST 28 where CreateTime>=@BeginTime and CreateTime<@EndTime 29 ',N'@BeginTime date,@EndTime date', 30 @BeginTime='2011-11-04 00:00:00', 31 @EndTime='2011-11-04 23:59:59' 32 33 --又看下面的例子 34 DECLARE @EndTime datetime 35 SET @EndTime='2011-11-04 23:59:59' 36 DECLARE @CreateTime DATE 37 SET @CreateTime='2011-11-04' 38 39 IF @CreateTime<@EndTime --打印出来，可以理解，但为啥前面的不对呢？ 40 PRINT '@CreateTime<@EndTime'