Table Comparison Procedure

CREATE PROCEDURE [dbo].[GetComparison_SECOND] (@first_db varchar(100), @first_table varchar(100), @first_col_list varchar(1000), 
                                              @second_db varchar(100), @second_table varchar(100), @second_col_list varchar(1000))
as 
declare 
@sql1 varchar(3000),
@sql2 varchar(3000),
@sql3 varchar(3000),
@sql_pk varchar(3000),
@col_name varchar(100),
@counter int, 
@data_type varchar(50);
declare @key_cur as cursor; 
SET @sql1 = ''
SET @sql2 = ''
set @sql_pk = ''


if @second_col_list = '' SET @second_col_list = @first_col_list
IF OBJECT_ID('tempdb..#KeysTemp') IS NOT NULL 
        DROP TABLE #KeysTemp;
BEGIN
SET @sql_pk = 'select KCU.COLUMN_name COL_NAME, c.DATA_TYPE, c.CHARACTER_MAXIMUM_LENGTH CHAR_LENGTH, c.NUMERIC_PRECISION NUMERIC_PRECISION, 
              c.NUMERIC_PRECISION_RADIX NUMERIC_PREC_RADIX
              from '+@second_db
              +'.INFORMATION_SCHEMA.KEY_COLUMN_USAGE KCU
              Join '+@second_db+'.INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC
              ON  KCU.CONSTRAINT_SCHEMA = TC.CONSTRAINT_SCHEMA
              AND KCU.CONSTRAINT_NAME = TC.CONSTRAINT_NAME
              AND KCU.TABLE_SCHEMA = TC.TABLE_SCHEMA
              AND KCU.TABLE_NAME = TC.TABLE_NAME
              join '+@second_db+'.INFORMATION_SCHEMA.COLUMNS C
              ON c.TABLE_CATALOG = tc.TABLE_CATALOG
              and c.TABLE_SCHEMA = tc.TABLE_SCHEMA
              and c.TABLE_NAME = tc.TABLE_NAME
              and c.COLUMN_NAME = kcu.COLUMN_NAME
              and TC.TABLE_CATALOG = '''+@second_db+''' and TC.TABLE_NAME = '''+@second_table+''''

        
CREATE TABLE #KeysTemp
( 
 COL_NAME VARCHAR(100), 
 DATA_TYPE VARCHAR(50), 
 CHAR_LENGTH INT, 
 NUMERIC_PRECISION INT, 
 NUMERIC_PREC_RADIX INT
 )       
Insert 
into #KeysTemp
exec (@sql_pk)

SET @sql1 = 'SELECT '+@first_col_list++CHAR(10)+' FROM '+@first_db+'.dbo.'+@first_table+ ' as COPY'+CHAR(10)+
           ' WHERE EXISTS'+ CHAR(10)+
           '(SELECT '+@second_col_list++CHAR(10)+' FROM '+@second_db+'.dbo.'+@second_table +' as ORIG'+ CHAR(10)+
           ' WHERE '+ CHAR(10)

SET @key_cur = CURSOR FOR 
                SELECT COL_NAME, DATA_TYPE 
                from #KeysTemp ;
set @counter = 0
    OPEN @key_cur 
FETCH NEXT FROM @key_cur into @col_name, @data_type;
WHILE @@FETCH_STATUS = 0
BEGIN
     select @counter = @counter + 1
     IF @counter = 1 
 IF @data_type = 'varchar'
BEGIN
SET @sql2 = 'ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+' ,0)'
END 
ELSE IF @data_type = 'int'
BEGIN
SET @sql2 = 'ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+',0)'
END
ELSE IF @data_type = 'datetime'
BEGIN
SET @sql2 = 'ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+',0)'
END 
ELSE IF @data_type = 'float'
BEGIN
SET @sql2 = 'ORIG.'+@col_name +' = ISNULL(CAST(LTRIM(RTRIM(COPY.'+@col_name+')) as VARCHAR(10)),0)'
END   
ELSE SET @sql2 = 'ORIG.'+@col_name +'= COPY.'+@col_name 
      
     ELSE
     
     IF @data_type = 'varchar'
BEGIN
SET @sql2 = @sql2 + CHAR(10)+' and ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+',0)'
END 
ELSE IF @data_type = 'int'
BEGIN
SET @sql2 = @sql2 + CHAR(10)+' and ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+',0)'
END
ELSE IF @data_type = 'datetime'
BEGIN
SET @sql2 = @sql2 + CHAR(10)+' and ORIG.'+@col_name +' = ISNULL(COPY.'+@col_name+',0)'
END 
ELSE IF @data_type = 'float'
BEGIN
SET @sql2 = @sql2 + CHAR(10)+' and ORIG.'+@col_name +' = ISNULL(CAST(LTRIM(RTRIM(COPY.'+@col_name+')) as VARCHAR(10)),0)'
END   

ELSE SET @sql2 = @sql2 + CHAR(10)+' and ORIG.'+@col_name +' = COPY.'+@col_name 

     
     FETCH NEXT FROM @key_cur into @col_name, @data_type;
END
CLOSE @key_cur;
DEALLOCATE @key_cur;

SET @sql3 = ''     
 
           
SET @sql3 = @sql1 + @sql2++CHAR(10)+')'           

print @sql3

exec (@sql3)
END