database/sql: add NullInt64, NullFloat64, NullBool
Fixes #2699
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5557063
diff --git a/src/pkg/database/sql/sql.go b/src/pkg/database/sql/sql.go
index a8bf2a8..70499b9 100644
--- a/src/pkg/database/sql/sql.go
+++ b/src/pkg/database/sql/sql.go
@@ -47,7 +47,6 @@
// // NULL value
// }
//
-// TODO(bradfitz): add other types.
type NullString struct {
String string
Valid bool // Valid is true if String is not NULL
@@ -71,6 +70,84 @@
return ns.String, nil
}
+// NullInt64 represents an int64 that may be null.
+// NullInt64 implements the ScannerInto interface so
+// it can be used as a scan destination, similar to NullString.
+type NullInt64 struct {
+ Int64 int64
+ Valid bool // Valid is true if Int64 is not NULL
+}
+
+// ScanInto implements the ScannerInto interface.
+func (n *NullInt64) ScanInto(value interface{}) error {
+ if value == nil {
+ n.Int64, n.Valid = 0, false
+ return nil
+ }
+ n.Valid = true
+ return convertAssign(&n.Int64, value)
+}
+
+// SubsetValue implements the driver SubsetValuer interface.
+func (n NullInt64) SubsetValue() (interface{}, error) {
+ if !n.Valid {
+ return nil, nil
+ }
+ return n.Int64, nil
+}
+
+// NullFloat64 represents a float64 that may be null.
+// NullFloat64 implements the ScannerInto interface so
+// it can be used as a scan destination, similar to NullString.
+type NullFloat64 struct {
+ Float64 float64
+ Valid bool // Valid is true if Float64 is not NULL
+}
+
+// ScanInto implements the ScannerInto interface.
+func (n *NullFloat64) ScanInto(value interface{}) error {
+ if value == nil {
+ n.Float64, n.Valid = 0, false
+ return nil
+ }
+ n.Valid = true
+ return convertAssign(&n.Float64, value)
+}
+
+// SubsetValue implements the driver SubsetValuer interface.
+func (n NullFloat64) SubsetValue() (interface{}, error) {
+ if !n.Valid {
+ return nil, nil
+ }
+ return n.Float64, nil
+}
+
+// NullBool represents a bool that may be null.
+// NullBool implements the ScannerInto interface so
+// it can be used as a scan destination, similar to NullString.
+type NullBool struct {
+ Bool bool
+ Valid bool // Valid is true if Bool is not NULL
+}
+
+// ScanInto implements the ScannerInto interface.
+func (n *NullBool) ScanInto(value interface{}) error {
+ if value == nil {
+ n.Bool, n.Valid = false, false
+ return nil
+ }
+ n.Valid = true
+ return convertAssign(&n.Bool, value)
+}
+
+// SubsetValue implements the driver SubsetValuer interface.
+func (n NullBool) SubsetValue() (interface{}, error) {
+ if !n.Valid {
+ return nil, nil
+ }
+ return n.Bool, nil
+}
+
// ScannerInto is an interface used by Scan.
type ScannerInto interface {
// ScanInto assigns a value from a database driver.
