NUMERIC和VARCHAR(NUMERIC and VARCHAR)

 我使用SQL Server 2008 R2来运行查询，我遇到了一个数据库，它将数值存储为varchar(4) 。 例如： 
 
SELECT [num]
FROM  [TABLE1]
WHERE num > '95'
 
 我得到以下结果 
 
96
97
98
99
999
 
 但是，当我运行相同的查询时没有''ie 
 
SELECT [num]
FROM  [TABLE1]
WHERE num > 95
 
 然后我明白了 
 
100
101
102
103
104
105
106
107
108
109
110
111
112
113
116
117
120
7001
7002
7003
7004
7005
7006
7007
96
97
98
99
999
 
 在任何情况下，我都没有按顺序获得数字，即95,96,97,98,99。我理解这是因为它们存储为varchar（4），即字符串格式。 有人可以解释在这两种情况下会发生什么，以及在上述两种情况下字符串如何比较？ 
 
 另外，如果有人可以帮助我编写代码以便将这些varchar（4）动态更改为数字，那么我可以正确地安排它们吗？ 
 
 非常感激。 

I am using SQL Server 2008 R2 to run queries and I have come across a database where it stores numeric values as varchar(4). For example:
 
SELECT [num]
FROM  [TABLE1]
WHERE num > '95'
 
I get the below results 
 
96
97
98
99
999
 
However when I run the same query without the '' i.e. 
 
SELECT [num]
FROM  [TABLE1]
WHERE num > 95
 
then I get 
 
100
101
102
103
104
105
106
107
108
109
110
111
112
113
116
117
120
7001
7002
7003
7004
7005
7006
7007
96
97
98
99
999
 
In any case, I am not getting numbers in order i.e. 95, 96, 97, 98, 99. I understand this is because they are stored as varchar(4) i.e. of a string format. Please can someone explain what happens in both situations and how does a string compare in both the above cases?
 
Also if someone can help me write the code to change these varchar(4) into numeric on the fly so I can arrange them properly?
 
Much appreciated.

原文：https://stackoverflow.com/questions/28265918