What knowledge of sql does a junior .net developer need?

Question

SQL

I heard that the most important thing is to understand joins (join), and the rest is not necessary. Well, just for understanding.

Answer 1

SQL from a user's point of view, not an administrator's, is a fairly simple thing.
To understand selections, joins, to be able to create a database / set up rights - this is the user level.
Deal with the optimization of tables, indexes - the level of a good advanced user.
Deal with backups, restores, replications - administrator level.
Junior-have enough of the first option, then move on to the second. The third is optional.

Answer 2

IMHO that is just simple. Much more interesting is the use of groupings.