Sha256: c6bd155e16bea2b95fd537c52834aa17aaa19aaf5b98ded30e8b89a088aaeae9
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Size: 641 Bytes
Versions: 8
Compression:
Stored size: 641 Bytes
Contents
Relational restriction (aka where, predicate filtering)
SYNOPSIS
#(signature)
DESCRIPTION
This command restricts restricts relations to those tuples for which PREDICATE
evaluates to true.
PREDICATE must be a valid tuple expression that returns a truth-value. It
may be specified as a ruby code literal, or a mapping between (name, value)
pairs. In the latter case, PREDICATE is built as a conjunction of attribute
equalities.
EXAMPLE
# Who are suppliers with a status greater than 20?
!(alf restrict suppliers -- "status > 20")
# Which suppliers live in London?
!(alf restrict suppliers -- city "'London'")
Version data entries
8 entries across 8 versions & 2 rubygems