How can I see all the “special” characters permissible in a varchar or char field in SQL Server? [closed]

Answer 1

i think that special characters are # and @ only... query will list both.

DECLARE  @str VARCHAR(50) 
SET @str = '[azAB09ram#reddy@wer45' + CHAR(5) + 'a~b$' 
SELECT DISTINCT poschar 
FROM   MASTER..spt_values S 
       CROSS APPLY (SELECT SUBSTRING(@str,NUMBER,1) AS poschar) t 
WHERE  NUMBER > 0 
       AND NUMBER <= LEN(@str) 
       AND NOT (ASCII(t.poschar) BETWEEN 65 AND 90 
                 OR ASCII(t.poschar) BETWEEN 97 AND 122 
                 OR ASCII(t.poschar) BETWEEN 48 AND 57) 

Answer 2

You probably just need to see the ASCII and EXTENDED ASCII character sets. As far as I know any of these are allowed in a char/varchar field.

If you use nchar/nvarchar then it's pretty much any character in any unicode set in the world.

Answer 3

EDIT based on comments:

If you have line breaks in your result set and want to remove them, make your query this way:

SELECT
    REPLACE(REPLACE(YourColumn1,CHAR(13),' '),CHAR(10),' ')
   ,REPLACE(REPLACE(YourColumn2,CHAR(13),' '),CHAR(10),' ')
   ,REPLACE(REPLACE(YourColumn3,CHAR(13),' '),CHAR(10),' ')
   --^^^^^^^^^^^^^^^           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   --only add the above code to strings that are having line breaks, not to numbers or dates
   FROM YourTable...
   WHERE ...

This will replace all the line breaks with a space character.

Run this to "get" all characters permitted in a char() and varchar():

;WITH AllNumbers AS
(
    SELECT 1 AS Number
    UNION ALL
    SELECT Number+1
        FROM AllNumbers
        WHERE Number+1<256
)
SELECT Number AS ASCII_Value,CHAR(Number) AS ASCII_Char FROM AllNumbers
OPTION (MAXRECURSION 256)

OUTPUT:

ASCII_Value ASCII_Char
----------- ----------
1           
2           
3           
4           
5           
6           
7           
8           
9               
10          

11          
12          
13          

14          
15          
16          
17          
18          
19          
20          
21          
22          
23          
24          
25          
26          
27          
28          
29          
30          
31          
32           
33          !
34          "
35          #
36          $
37          %
38          &
39          '
40          (
41          )
42          *
43          +
44          ,
45          -
46          .
47          /
48          0
49          1
50          2
51          3
52          4
53          5
54          6
55          7
56          8
57          9
58          :
59          ;
60          <
61          =
62          >
63          ?
64          @
65          A
66          B
67          C
68          D
69          E
70          F
71          G
72          H
73          I
74          J
75          K
76          L
77          M
78          N
79          O
80          P
81          Q
82          R
83          S
84          T
85          U
86          V
87          W
88          X
89          Y
90          Z
91          [
92          \
93          ]
94          ^
95          _
96          `
97          a
98          b
99          c
100         d
101         e
102         f
103         g
104         h
105         i
106         j
107         k
108         l
109         m
110         n
111         o
112         p
113         q
114         r
115         s
116         t
117         u
118         v
119         w
120         x
121         y
122         z
123         {
124         |
125         }
126         ~
127         
128         €
129         
130         ‚
131         ƒ
132         „
133         …
134         †
135         ‡
136         ˆ
137         ‰
138         Š
139         ‹
140         Œ
141         
142         Ž
143         
144         
145         ‘
146         ’
147         “
148         ”
149         •
150         –
151         —
152         ˜
153         ™
154         š
155         ›
156         œ
157         
158         ž
159         Ÿ
160          
161         ¡
162         ¢
163         £
164         ¤
165         ¥
166         ¦
167         §
168         ¨
169         ©
170         ª
171         «
172         ¬
173         ­
174         ®
175         ¯
176         °
177         ±
178         ²
179         ³
180         ´
181         µ
182         ¶
183         ·
184         ¸
185         ¹
186         º
187         »
188         ¼
189         ½
190         ¾
191         ¿
192         À
193         Á
194         Â
195         Ã
196         Ä
197         Å
198         Æ
199         Ç
200         È
201         É
202         Ê
203         Ë
204         Ì
205         Í
206         Î
207         Ï
208         Ð
209         Ñ
210         Ò
211         Ó
212         Ô
213         Õ
214         Ö
215         ×
216         Ø
217         Ù
218         Ú
219         Û
220         Ü
221         Ý
222         Þ
223         ß
224         à
225         á
226         â
227         ã
228         ä
229         å
230         æ
231         ç
232         è
233         é
234         ê
235         ë
236         ì
237         í
238         î
239         ï
240         ð
241         ñ
242         ò
243         ó
244         ô
245         õ
246         ö
247         ÷
248         ø
249         ù
250         ú
251         û
252         ü
253         ý
254         þ
255         ÿ

(255 row(s) affected)

Answer 4

The specific characters that can be stored in a varchar or char column depend upon the column collation. See my answer here for a script that will show you these for the various different collations.

If you want to find all characters outside a particular ASCII range see my answer here.