Insert into … values ( SELECT … FROM … )

Question

I am trying to INSERT INTO a table using the input from another table. Although this is entirely feasible for many database engines, I always seem to struggle t

Answer 1

Here's how to insert from multiple tables. This particular example is where you have a mapping table in a many to many scenario:

insert into StudentCourseMap (StudentId, CourseId) 
SELECT  Student.Id, Course.Id FROM Student, Course 
WHERE Student.Name = 'Paddy Murphy' AND Course.Name = 'Basket weaving for beginners'

(I realise matching on the student name might return more than one value but you get the idea. Matching on something other than an Id is necessary when the Id is an Identity column and is unknown.)