def rel_join(query: pgast.Query, right_rvar: pgast.BaseRangeVar, *,
ctx: context.CompilerContextLevel) -> None:
condition = None
for path_id in right_rvar.path_scope:
lref = maybe_get_path_var(query, path_id, aspect='identity', ctx=ctx)
if lref is None:
lref = maybe_get_path_var(query, path_id, aspect='value', ctx=ctx)
if lref is None:
continue
rref = pathctx.get_rvar_path_identity_var(right_rvar,
path_id,
env=ctx.env)
path_cond = astutils.join_condition(lref, rref)
condition = astutils.extend_binop(condition, path_cond)
if condition is None:
join_type = 'cross'
else:
join_type = 'inner'
if not query.from_clause:
query.from_clause.append(right_rvar)
if condition is not None:
query.where_clause = astutils.extend_binop(query.where_clause,
condition)
else:
larg = query.from_clause[0]
rarg = right_rvar
query.from_clause[0] = pgast.JoinExpr(type=join_type,
larg=larg,
rarg=rarg,
quals=condition)
if join_type == 'left':
right_rvar.nullable = True
if not right_rvar.is_distinct:
query.is_distinct = False
def put_rvar_path_output(rvar: pgast.BaseRangeVar, path_id: irast.PathId,
aspect: str, var: pgast.OutputVar, *,
env: context.Environment) -> None:
rvar.path_outputs[path_id, aspect] = var