Where clause in Stored Procedure SQL - sql-server

Question

New to stored Procedure - Can someone help me in troubleshooting the problem please? I want to achieve something as simple as :
update Table_A set Column_A = New Value where Column_A = OldValue;
but converting this to a Stored Procedure is problematic.
alter PROC test_proc
#ColumnValue as Varchar(100),
#TableValue as Varchar(50),
#NewValue as Varchar(50),
#OldValue as Varchar(50)
as
begin
Declare #Pointer VarChar(1000)
Declare Test_Cur Cursor For
Select 'Update ' + TABLE_NAME + ' set ' + COLUMN_NAME + ' = ''' + #NewValue + ''''
From INFORMATION_SCHEMA.COLUMNS
Where column_name = #OldValue
and column_name = #ColumnValue
and TABLE_NAME like #TableValue
Open Test_Cur
-- Loop the cursor and execution of requests
Fetch Next From Test_Cur Into #Pointer
While (##Fetch_Status = 0)
Begin
Print #Pointer
Execute (#Pointer)
Fetch Next From Test_Cur Into #Pointer
End
-- Closing the cursor and releasing resources
Close Test_Cur
Deallocate Test_Cur
Print 'Update complete!'
end
exec dbo.test_proc #ColumnValue = 'USERCHANGED',#TableValue = 'H_%', #OldValue = '12', #NewValue = '14'
If I remove the line "Where column_name = #OldValue", the problem goes but it doesn't help me achieve my target. Suggestions please.

Answer 1

I think you mixed internal where with external one, try this ( I couldn't check, may be i misplaced an apex):
alter PROC test_proc
#ColumnValue as Varchar(100),
#TableValue as Varchar(50),
#NewValue as Varchar(50),
#OldValue as Varchar(50)
as
begin
Declare #Pointer VarChar(1000)
Declare Test_Cur Cursor For
Select 'Update ' + TABLE_NAME + ' set ' + COLUMN_NAME + ' = ''' + #NewValue + ''' WHERE ' + + COLUMN_NAME + ' = ''' + #OldValue + ''''
From INFORMATION_SCHEMA.COLUMNS
Where column_name = #ColumnValue
and TABLE_NAME like #TableValue
Open Test_Cur
-- Loop the cursor and execution of requests
Fetch Next From Test_Cur Into #Pointer
While (##Fetch_Status = 0)
Begin
Print #Pointer
Execute (#Pointer)
Fetch Next From Test_Cur Into #Pointer
End
-- Closing the cursor and releasing resources
Close Test_Cur
Deallocate Test_Cur
Print 'Update complete!'
end

Answer 2

This is the logic for your cursor:
Select 'Update ' + TABLE_NAME + ' set ' + COLUMN_NAME + ' = ''' + #NewValue + ''''
From INFORMATION_SCHEMA.COLUMNS
Where column_name = #OldValue and
----------^
column_name = #ColumnValue and
----------^
TABLE_NAME like #TableValue;
The first and second conditions conflict with each other. I think your intention is just:
Select 'Update ' + TABLE_NAME + ' set ' + COLUMN_NAME + ' = ''' + #NewValue + ''''
From INFORMATION_SCHEMA.COLUMNS
Where column_name = #ColumnValue and
TABLE_NAME like #TableValue;
You might want to rename #ColumnValue to something like #ColumnName, which seems more apt for its use.
EDIT:
I think your intention is:
Select 'Update ' + TABLE_NAME + ' set ' + COLUMN_NAME + ' = ''' + #NewValue + ''' where ' + COLUMN_NAME + ' = ''' + #NewValue + ''''
From INFORMATION_SCHEMA.COLUMNS
Where column_name = #ColumnValue and
TABLE_NAME like #TableValue;