database/sql: document expectations for named parameters

Require parameter names to not begin with a symbol.

Change-Id: I5dfe9d4e181f0daf71dad2f395aca41c68678cbe
Reviewed-on: https://go-review.googlesource.com/33493
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/database/sql/convert.go b/src/database/sql/convert.go
index 4b4dfc40d7..ea2f377810 100644
--- a/src/database/sql/convert.go
+++ b/src/database/sql/convert.go
@@ -13,6 +13,8 @@ import (
 	"reflect"
 	"strconv"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var errNilPtr = errors.New("destination pointer is nil") // embedded in descriptive error
@@ -24,6 +26,17 @@ func describeNamedValue(nv *driver.NamedValue) string {
 	return fmt.Sprintf("with name %q", nv.Name)
 }
 
+func validateNamedValueName(name string) error {
+	if len(name) == 0 {
+		return nil
+	}
+	r, _ := utf8.DecodeRuneInString(name)
+	if unicode.IsLetter(r) {
+		return nil
+	}
+	return fmt.Errorf("name %q does not begin with a letter", name)
+}
+
 // driverArgs converts arguments from callers of Stmt.Exec and
 // Stmt.Query into driver Values.
 //
@@ -43,6 +56,9 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.NamedValue, error)
 			nv := &nvargs[n]
 			nv.Ordinal = n + 1
 			if np, ok := arg.(NamedArg); ok {
+				if err := validateNamedValueName(np.Name); err != nil {
+					return nil, err
+				}
 				arg = np.Value
 				nvargs[n].Name = np.Name
 			}
@@ -60,6 +76,9 @@ func driverArgs(ds *driverStmt, args []interface{}) ([]driver.NamedValue, error)
 		nv := &nvargs[n]
 		nv.Ordinal = n + 1
 		if np, ok := arg.(NamedArg); ok {
+			if err := validateNamedValueName(np.Name); err != nil {
+				return nil, err
+			}
 			arg = np.Value
 			nv.Name = np.Name
 		}