Method simpleQuery

conn.go:625–700

(q string)

}

func (cn *conn) simpleQuery(q string) (*rows, error) {
	if debugProto {
		fmt.Fprintln(os.Stderr, "         START conn.simpleQuery")
		defer fmt.Fprintln(os.Stderr, "         END conn.simpleQuery")
	}

	b := cn.writeBuf(proto.Query)
	b.string(q)
	err := cn.send(b)
	if err != nil {
		return nil, cn.handleError(err, q)
	}

	var (
		res    *rows
		resErr error
	)
	for {
		t, r, err := cn.recv1()
		if err != nil {
			return nil, cn.handleError(err, q)
		}
		switch t {
		case proto.CommandComplete, proto.EmptyQueryResponse:
			// We allow queries which don't return any results through Query as
			// well as Exec. We still have to give database/sql a rows object
			// the user can close, though, to avoid connections from being
			// leaked. A "rows" with done=true works fine for that purpose.
			if resErr != nil {
				cn.err.set(driver.ErrBadConn)
				return nil, fmt.Errorf("pq: unexpected message %q in simple query execution", t)
			}
			if res == nil {
				res = &rows{cn: cn}
			}
			// Set the result and tag to the last command complete if there wasn't a
			// query already run. Although queries usually return from here and cede
			// control to Next, a query with zero results does not.
			if t == proto.CommandComplete {
				res.result, res.tag, err = cn.parseComplete(r.string())
				if err != nil {
					return nil, cn.handleError(err, q)
				}
				if res.colNames != nil {
					return res, cn.handleError(resErr, q)
				}
			}
			res.done = true
		case proto.ReadyForQuery:
			cn.processReadyForQuery(r)
			if err == nil && res == nil {
				res = &rows{done: true}
			}
			return res, cn.handleError(resErr, q) // done
		case proto.ErrorResponse:
			res = nil
			resErr = parseError(r, q)
		case proto.DataRow: