Counting characters in an Access database column using SQL - sql

Question

I have the following table
col1 col2 col3 col4
==== ==== ==== ====
1233 4566 ABCD CDEF
1233 4566 ACD1 CDEF
1233 4566 D1AF CDEF
I need to count the characters in col3, so from the data in the previous table it would be:
char count
==== =====
A 3
B 1
C 2
D 3
F 1
1 2
Is this possible to achieve by using SQL only?
At the moment I am thinking of passing a parameter in to SQL query and count the characters one by one and then sum, however I did not start the VBA part yet, and frankly wouldn't want to do that.
This is my query at the moment:
PARAMETERS X Long;
SELECT First(Mid(TABLE.col3,X,1)) AS [col3 Field], Count(Mid(TABLE.col3,X,1)) AS Dcount
FROM TEST
GROUP BY Mid(TABLE.col3,X,1)
HAVING (((Count(Mid([TABLE].[col3],[X],1)))>=1));
Ideas and help are much appreciated, as I don't usually work with Access and SQL.

Answer 1

You can accomplish your task in pure Access SQL by using a Numbers table. In this case, the Numbers table must contain integer values from 1 to some number larger than the longest string of characters in your source data. In this example, the strings of characters to be processed are in [CharacterData]:
CharacterList
-------------
GORD
WAS
HERE
and the [Numbers] table is simply
n
--
1
2
3
4
5
If we use a cross join to extract the characters (eliminating any empty strings that result from n exceeding Len(CharacterList))...
SELECT
Mid(cd.CharacterList, nb.n, 1) AS c
FROM
CharacterData cd,
Numbers nb
WHERE Mid(cd.CharacterList, nb.n, 1) <> ""
...we get ...
c
--
G
W
H
O
A
E
R
S
R
D
E
Now we can just wrap that in an aggregation query
SELECT c AS Character, COUNT(*) AS CountOfCharacter
FROM
(
SELECT
Mid(cd.CharacterList, nb.n, 1) AS c
FROM
CharacterData cd,
Numbers nb
WHERE Mid(cd.CharacterList, nb.n, 1) <> ""
)
GROUP BY c
which gives us
Character CountOfCharacter
--------- ----------------
A 1
D 1
E 2
G 1
H 1
O 1
R 2
S 1
W 1

Answer 2

Knowing that colum3 has a fixed length of 4, this problem is quite easy.
Assume there is a view V with four columns, each for one character in column 3.
V(c1, c2, c3, c4)
Unfortunately, I'm not familiar with Access-specific SQL, but this is the general SQL statement you would need:
SELECT c, COUNT(*) FROM
(
SELECT c1 AS c FROM V
UNION ALL
SELECT c2 FROM V
UNION ALL
SELECT c3 FROM V
UNION ALL
SELECT c4 FROM V
)
GROUP BY c

Answer 3

It's a shame that you don't want to consider using VBA; you don't need as much as you might think:
Public charCounts As Dictionary
Sub LoadCounts(s As String)
If charCounts Is Nothing Then Init
Dim length As Integer, i As Variant
length = Len(s)
For i = 1 To length
Dim currentChar As String
currentChar = Mid(s, i, 1)
If Not charCounts.Exists(currentChar) Then charCounts(currentChar) = 0
charCounts(currentChar) = charCounts(currentChar) + 1
Next
End Sub
Sub Init()
Set charCounts = New Scripting.Dictionary
charCounts.CompareMode = TextCompare 'for case-insensitive comparisons; otherwise use BinaryCompare
End Sub
Then, you execute the query once:
SELECT LoadCount(col3)
FROM Table1
Finally, you read out the values in the Dictionary:
Dim key As Variant
For Each key In charCounts
Debug.Print key, charCounts(key)
Next
Note that between query executions you have to call Init to clear out the old values.

Answer 4

Please Try this,,, I hope this will work
with cte as
(
select row_number() over(order by (select null)) as i from Charactor_Count
)
select substring( name, i, 1 ) as char, count(*) as count
from Charactor_Count, cte
where cte.i <= len(Charactor_Count.name)
group by substring(name,i,1)
order by substring(name,i,1)