Find the column(s) with values which has special characters using SQL - sql

Question

I have some tables in a DB as mentioned below.,
**Table1**
+-------+--------------+-------------+
|**ID** |**Name** |**Country** |
+-------+--------------+-------------+
| 1 |Avinash Kumar |India |
| 2 |Sat!sh#S |USA |
| 3 |$32kjs |UK |
| 4 |#$### |AFRICA |
| 5 |Krishnas_has |USA |
+-------+--------------+-------------+
**Table2**
+-------+--------------+-------------+-----------+
|**ID** |**Name1** |**Country1** |**Region1**|
+-------+--------------+-------------+-----------+
| 1 |Avinash Kumar |India |EMEA |
| 2 |Sat!sh#S |USA |ASIA## |
| 3 |$32kjs |UK |EU._A |
| 4 |#$### |AFRICA |HAS&# |
| 5 |Krishnas_has |USA |KALc!! |
+-------+--------------+-------------+-----------+
**Table3**
+-------+--------------+-------------+-----------+-----------+
|**ID** |**Name2** |**Country2** |**Region2**|**State2** |
+-------+--------------+-------------+-----------+-----------+
| 1 |Avinash.Kumar |India$ |EMEA |BANG_& |
| 2 |Sat!sh#S |US!!A |ASIA## |SO$TH |
| 3 |$32kjs |U#K |EU._A |TRUTH |
| 4 |#$### |AFRICA |HAS |HAPPY |
| 5 |Krishnas_has |USA# |KALc!! |!ASDF# |
+-------+--------------+-------------+-----------+-----------+
And one more thing is like I want to pass the table name as variable. Something like this
Declare #Table
Select * from #Table
What ever I pass in #Table the code has to work dynamically
Now how can I find the special character columns if i pass #Table = Table3
For example: My output should be like this when I want to find special characters in Table3
**EXPECTED OUTPUT**
+-------+--------------+-------------+-----------+-----------+
|**ID** |**Name2** |**Country2** |**Region2**|**State2** |
+-------+--------------+-------------+-----------+-----------+
| 1 |Avinash.Kumar |India$ | |BANG_& |
| 2 |Sat!sh#S |US!!A |ASIA## |SO$TH |
| 3 |$32kjs |U#K |EU._A | |
| 4 |#$### | | | |
| 5 |Krishnas_has |USA# |KALc!! |!ASDF# |
+-------+--------------+-------------+-----------+-----------+
Can someone please help me with this?
Thanks in advance!

Answer 1

Have a look at this approach:
CREATE TABLE Test (
ID INT,
Name2 NVARCHAR(100),
Country2 NVARCHAR(100),
Region2 NVARCHAR(100),
State2 NVARCHAR(100)
)
GO
DELETE test
INSERT INTO Test VALUES(1, 'Avinash.Kumar', 'India$', 'EMEA', 'BANG_&'), (2, 'Sat!sh#S', 'US!!A', 'ASIA', 'SO$TH'), (3, 'Test1', 'Test2', 'Test3', 'Test4')
GO
CREATE FUNCTION chkStrg4Chars(#InputString NVARCHAR(4000)) RETURNS NVARCHAR(4000)
AS
BEGIN
DECLARE #RetVal NVARCHAR(4000);
SET #RetVal = CASE WHEN #InputString LIKE '%[^A-Za-z0-9 .]%' THEN #InputString ELSE NULL END;
RETURN #RetVal
END;
GO
CREATE PROCEDURE chkTableColumns4Chars(#InputTable NVARCHAR(500))
AS
BEGIN
DECLARE #ColList NVARCHAR(MAX);
DECLARE #ColListNonC NVARCHAR(MAX);
DECLARE #ColListRes NVARCHAR(MAX);
DECLARE #ColListPiv NVARCHAR(MAX);
SELECT #ColList = (SELECT CASE WHEN t.name IN ('nvarchar','varchar') THEN 'dbo.chkStrg4Chars(' + c.name + ') AS ' + c.name ELSE c.name END + ','
FROM sys.columns c
JOIN sys.types t ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
WHERE c.object_id = OBJECT_ID(#InputTable)
ORDER BY c.column_id
FOR XML PATH('')
);
SET #ColList = SUBSTRING(#ColList, 1, LEN(#ColList)-1);
SELECT #ColListRes = (SELECT 'MAX(' + c.name + ') AS ' + c.name + ','
FROM sys.columns c
JOIN sys.types t ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
WHERE c.object_id = OBJECT_ID(#InputTable)
AND t.name IN ('nvarchar','varchar')
ORDER BY c.column_id
FOR XML PATH('')
);
SET #ColListRes = SUBSTRING(#ColListRes, 1, LEN(#ColListRes)-1);
SELECT #ColListNonC = (SELECT c.name + ','
FROM sys.columns c
JOIN sys.types t ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
WHERE c.object_id = OBJECT_ID(#InputTable)
AND t.name NOT IN ('nvarchar','varchar')
ORDER BY c.column_id
FOR XML PATH('')
);
SELECT #ColListPiv = (SELECT c.name + ','
FROM sys.columns c
JOIN sys.types t ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id
WHERE c.object_id = OBJECT_ID(#InputTable)
AND t.name IN ('nvarchar','varchar')
ORDER BY c.column_id
FOR XML PATH('')
);
SET #ColListPiv = SUBSTRING(#ColListPiv, 1, LEN(#ColListPiv)-1);
DECLARE #stmt NVARCHAR(MAX) = 'SELECT ' + #ColList + ' INTO #TTest1 FROM ' + #InputTable + ';
DECLARE #SubCol nvarchar(max) = (SELECT ColName + ' + CHAR(39) + ',' + CHAR(39) + ' FROM (SELECT ' + #ColListRes + ' FROM #TTest1) x UNPIVOT (StrVal FOR ColName in (' + #ColListPiv + '))u FOR XML PATH('+CHAR(39)+CHAR(39)+'));
SET #SubCol = SUBSTRING(#SubCol, 1, len(#SubCol)-1)
DECLARE #SubStmt nvarchar(max) = ' + CHAR(39) + 'SELECT + ' + #ColListNonC + char(39) + ' + #SubCol + ' + CHAR(39) + ' FROM #TTest1 WHERE COALESCE( ' + CHAR(39) + ' + #SubCol + '+ CHAR(39) + ') IS NOT NULL' + CHAR(39) + ';
EXEC sp_executesql #SubStmt;'
EXEC sp_executesql #stmt;
END
GO
EXEC chkTableColumns4Chars 'dbo.Test'

Answer 2

As you said if you have lot of columns in your table, then writing the sql query to check each column would be a hectic work. For easiness we can do it by executing dynamic sql query.
Query
declare #sql as varchar(max);
select #sql = stuff((
select ', case when [' + [column_name] + '] like '
+ char(39) + '%[^A-Za-z0-9 ]%' + char(39)
+ ' then [' + [column_name] + '] else '
+ char(39) + char(39) + ' end as [' + [column_name] + '] '
from information_schema.columns
where table_name = 'your_table_name'
and [column_name] <> 'ID'
for xml path('')
)
, 1, 1, ''
);
select #sql = 'select [ID], ' + #sql + ' from [your_table_name];';
exec(#sql);