Add NamedQueryer interfaces to avoid unnecessary Execer dependency

named.go

@@ -436,9 +436,9 @@ func bindNamedMapper(bindType int, query string, arg interface{}, m *reflectx.Ma
 }
 
 // NamedQuery binds a named query and then runs Query on the result using the
-// provided Ext (sqlx.Tx, sqlx.Db).  It works with both structs and with
+// provided NamedQueryer (sqlx.Tx, sqlx.Db).  It works with both structs and with
 // map[string]interface{} types.
-func NamedQuery(e Ext, query string, arg interface{}) (*Rows, error) {
+func NamedQuery(e NamedQueryer, query string, arg interface{}) (*Rows, error) {
 	q, args, err := bindNamedMapper(BindType(e.DriverName()), query, arg, mapperFor(e))
 	if err != nil {
 		return nil, err

named_context.go

@@ -111,9 +111,9 @@ func (n *NamedStmt) GetContext(ctx context.Context, dest interface{}, arg interf
 }
 
 // NamedQueryContext binds a named query and then runs Query on the result using the
-// provided Ext (sqlx.Tx, sqlx.Db).  It works with both structs and with
+// provided NamedQueryerContext (sqlx.Tx, sqlx.Db).  It works with both structs and with
 // map[string]interface{} types.
-func NamedQueryContext(ctx context.Context, e ExtContext, query string, arg interface{}) (*Rows, error) {
+func NamedQueryContext(ctx context.Context, e NamedQueryerContext, query string, arg interface{}) (*Rows, error) {
 	q, args, err := bindNamedMapper(BindType(e.DriverName()), query, arg, mapperFor(e))
 	if err != nil {
 		return nil, err

sqlx.go

@@ -93,13 +93,20 @@ type binder interface {
 }
 
 // Ext is a union interface which can bind, query, and exec, used by
-// NamedQuery and NamedExec.
+// NamedExec.
 type Ext interface {
 	binder
 	Queryer
 	Execer
 }
 
+// NamedQueryer is a union interface which can bind and query, used by
+// NamedQuery.
+type NamedQueryer interface {
+	binder
+	Queryer
+}
+
 // Preparer is an interface used by Preparex.
 type Preparer interface {
 	Prepare(query string) (*sql.Stmt, error)

sqlx_context.go

@@ -40,13 +40,20 @@ type ExecerContext interface {
 }
 
 // ExtContext is a union interface which can bind, query, and exec, with Context
-// used by NamedQueryContext and NamedExecContext.
+// used by NamedExecContext.
 type ExtContext interface {
 	binder
 	QueryerContext
 	ExecerContext
 }
 
+// NamedQueryerContext is a union interface which can bind and query, with Context
+// used by NamedQueryContext.
+type NamedQueryerContext interface {
+	binder
+	QueryerContext
+}
+
 // SelectContext executes a query using the provided Queryer, and StructScans
 // each row into dest, which must be a slice.  If the slice elements are
 // scannable, then the result set must have only one column.  Otherwise,