mysql - Size of perticular rows of table which satisfy condition -

select (data_length)'size'  information_schema.tables  table_name='abc' 

this giving me total data size of table "abc". want data size of particular rows satisfy condition in clause.

say,

select (data_length)'size'  information_schema.tables  table_name='abc' , abc.id=1 

so,i want data_length of rows satisfies condition,but above not working.

i guess understand query.