sql数据排序与按日期排序

CREATE TABLE t1 (id int ,NAME varchar(10))
INSERT INTO t1
SELECT 1,'a'
UNION ALL
SELECT 3,'b'
UNION ALL
SELECT 10,'c'

CREATE TABLE t2(id int ,NAME varchar(10))
INSERT INTO t2
SELECT 1,'aa'
UNION ALL
SELECT 1,'aa'
UNION ALL
SELECT 3,'b'
UNION ALL
SELECT 10,'c'
UNION ALL
SELECT 10,'c'

SELECT * FROM t1 a LEFT JOIN t2 b ON A.id=b.id
ORDER BY a.id
/*
id          NAME       id          NAME
----------- ---------- ----------- ----------
1           a          1           aa
1           a          1           aa
3           b          3           b
10          c          10          c
10          c          10          c

(5 行受影响)
*/

SELECT email_address AS EmailAddress, CONVERT(nvarchar, lastcontact, 101) AS Last_Contact FROM Contact ORDER BY lastcontact DESC