def get_join_matches()

in ossdbtoolsservice/language/completion/pgcompleter.py [0:0]


    def get_join_matches(self, suggestion, word_before_cursor):
        tbls = suggestion.table_refs
        cols = self.populate_scoped_cols(tbls)
        # Set up some data structures for efficient access
        qualified = dict((normalize_ref(t.ref), t.schema) for t in tbls)
        ref_prio = dict((normalize_ref(t.ref), n) for n, t in enumerate(tbls))
        refs = set(normalize_ref(t.ref) for t in tbls)
        other_tbls = set((t.schema, t.name) for t in list(cols)[:-1])
        joins = []
        # Iterate over FKs in existing tables to find potential joins
        fks = ((fk, rtbl, rcol) for rtbl, rcols in cols.items()
               for rcol in rcols for fk in rcol.foreignkeys)
        col = namedtuple('col', 'schema tbl col')
        for fk, rtbl, rcol in fks:
            right = col(rtbl.schema, rtbl.name, rcol.name)
            child = col(fk.childschema, fk.childtable, fk.childcolumn)
            parent = col(fk.parentschema, fk.parenttable, fk.parentcolumn)
            left = child if parent == right else parent
            if suggestion.schema and left.schema != suggestion.schema:
                continue
            c = self.case
            if self.generate_aliases or normalize_ref(left.tbl) in refs:
                lref = self.alias(left.tbl, suggestion.table_refs)
                join = '{0} {4} ON {4}.{1} = {2}.{3}'.format(
                    c(left.tbl), c(left.col), rtbl.ref, c(right.col), lref)
            else:
                join = '{0} ON {0}.{1} = {2}.{3}'.format(
                    c(left.tbl), c(left.col), rtbl.ref, c(right.col))
            alias = generate_alias(self.case(left.tbl))
            synonyms = [join, '{0} ON {0}.{1} = {2}.{3}'.format(
                alias, c(left.col), rtbl.ref, c(right.col))]
            # Schema-qualify if (1) new table in same schema as old, and old
            # is schema-qualified, or (2) new in other schema, except public
            if not suggestion.schema and (qualified[normalize_ref(rtbl.ref)]
                                          and left.schema == right.schema
                                          or left.schema not in (right.schema, 'public')):
                join = left.schema + '.' + join
            prio = ref_prio[normalize_ref(rtbl.ref)] * 2 + (
                0 if (left.schema, left.tbl) in other_tbls else 1)
            joins.append(Candidate(join, prio, 'join', synonyms=synonyms))

        return self.find_matches(word_before_cursor, joins, meta='join')