CREATE TABLE TT(a_1 VARCHAR(1),a_2 VARCHAR(1),b_1 VARCHAR(1))
GO

INSERT INTO tt(a_1,a_2,b_1)
SELECT '1','1','b'
UNION 
SELECT '2','2','b'



SELECT DISTINCT
        'select ' + STUFF(( SELECT  ',' + name
                            FROM    sys.columns t
                            WHERE   object_id = sys.columns.object_id AND name LIKE 'a%'  --字段名起始字符
                          FOR
                            XML PATH('')
                          ), 1, 1, '') + ' from ' + OBJECT_NAME(object_id)
FROM    sys.columns
WHERE   object_id = OBJECT_ID('TT')

------解决方案--------------------

可能是我理解能力不好，没懂你的题目的意思！
SQL code

CREATE TABLE TT(a_1 VARCHAR(1),a_2 VARCHAR(1),b_1 VARCHAR(1))
GO

INSERT INTO tt(a_1,a_2,b_1)
SELECT '1','1','b'
UNION 
SELECT '2','2','b'



SELECT DISTINCT
        'select ' + STUFF(( SELECT  ',' + name
                            FROM    sys.columns t
                            WHERE   object_id = sys.columns.object_id AND name LIKE 'a%' FOR
                            XML PATH('') --把TT表中的列名查询出来组成 ，a_1,a_2这种类型字符串
                          ), 1, 1, '') --第一个开始替换一个字符串为空字符串
                          + ' from ' + OBJECT_NAME(object_id)
FROM    sys.columns
WHERE   object_id = OBJECT_ID('TT')