sql - Create new table from average of multiple columns in multiple tables -

sql - Create new table from average of multiple columns in multiple tables -

i have next query:

create table professor_average select instructor, sum( + instreffective_avg + howmuchlearned_avg + instrrespect_avg)/5 instreffective_average, howmuchlearned_average, instrrespect_average grouping instructor;

it telling me instructor ambiguous. how prepare this?

qualify instructor name of table came from.

for example: instreffective_average.instructor

if don't this, sql guess table of query came from, if there 2 or more possibilities doesn't seek guess , tells needs help deciding.

sql identifier cross-join