Sha256: 83caec2792442efc2929c8e21520f031eda1056a662f6b761960c8331e72b060
Contents?: true
Size: 818 Bytes
Versions: 8
Compression:
Stored size: 818 Bytes
Contents
Relational join (and cartesian product)
SYNOPSIS
#(signature)
DESCRIPTION
This operator computes the (natural) join of its operands.
Natural join means that, unlike what is commonly used in SQL, joining is based
on equality of all attributes that are shared between LEFT and RIGHT performed
on common attribute names. You can use the `rename` operator if this behavior
does not fit your needs.
When operands have no attribute in common, this operator naturally "degenerates"
to a cartesian product.
EXAMPLE
# Computes natural join of suppliers and supplies (on sid, the only
# attribute they have in common)
!(alf join suppliers supplies)
# The following example demontrates the cartesian product with a generated
# relation
!(alf generator -- 3 -- num | alf join cities)
Version data entries
8 entries across 8 versions & 2 rubygems