Chapter 7. SELECT Statement: The FROM Clause
If a table expression contains a
FROM clause, the processing starts with this clause. In fact, in this case, it is the starting point of processing a table expression, which is why we discuss this clause in detail first.
This chapter describes the basic features of the
FROM clause. In previous chapters, you saw many examples of this clause. The
FROM clause is an important clause because each table from which we “use” columns in the other clauses should be specified here. By “using,” we mean, for example, that a column appears in a condition or in the
SELECT clause. Simply, in the
FROM clause, we specify the tables from which the result of a table expression is retrieved.