source: code/trunk/vendor/github.com/google/uuid/sql.go@ 822

// Copyright 2016 Google Inc.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package uuid

import (
        "database/sql/driver"
        "fmt"
)

// Scan implements sql.Scanner so UUIDs can be read from databases transparently.
// Currently, database types that map to string and []byte are supported. Please
// consult database-specific driver documentation for matching types.
func (uuid *UUID) Scan(src interface{}) error {
        switch src := src.(type) {
        case nil:
                return nil

        case string:
                // if an empty UUID comes from a table, we return a null UUID
                if src == "" {
                        return nil
                }

                // see Parse for required string format
                u, err := Parse(src)
                if err != nil {
                        return fmt.Errorf("Scan: %v", err)
                }

                *uuid = u

        case []byte:
                // if an empty UUID comes from a table, we return a null UUID
                if len(src) == 0 {
                        return nil
                }

                // assumes a simple slice of bytes if 16 bytes
                // otherwise attempts to parse
                if len(src) != 16 {
                        return uuid.Scan(string(src))
                }
                copy((*uuid)[:], src)

        default:
                return fmt.Errorf("Scan: unable to scan type %T into UUID", src)
        }

        return nil
}

// Value implements sql.Valuer so that UUIDs can be written to databases
// transparently. Currently, UUIDs map to strings. Please consult
// database-specific driver documentation for matching types.
func (uuid UUID) Value() (driver.Value, error) {
        return uuid.String(), nil
}