查询以查找sql server中每行的百分比差异

I have a table with some columns in it. I would like to write a query that iterates through each row and find the total count of all rows that match a column in the selected row and also find the count of all rows that match 2 columns. With these 2 values, I would like to find the percentage difference and print them as column1, percentage(query1(column2)/query2(column2 and column3)).I have a table with some columns in it. I would