Add database/sql support to pgtype

pgtype/unknown.go

@@ -1,5 +1,7 @@
 package pgtype
 
+import "database/sql/driver"
+
 // Unknown represents the PostgreSQL unknown type. It is either a string literal
 // or NULL. It is used when PostgreSQL does not know the type of a value. In
 // general, this will only be used in pgx when selecting a null value without
@@ -30,3 +32,13 @@ func (dst *Unknown) DecodeText(ci *ConnInfo, src []byte) error {
 func (dst *Unknown) DecodeBinary(ci *ConnInfo, src []byte) error {
 	return (*Text)(dst).DecodeBinary(ci, src)
 }
+
+// Scan implements the database/sql Scanner interface.
+func (dst *Unknown) Scan(src interface{}) error {
+	return (*Text)(dst).Scan(src)
+}
+
+// Value implements the database/sql/driver Valuer interface.
+func (src Unknown) Value() (driver.Value, error) {
+	return (Text)(src).Value()
+}