diff --git a/xls2ddl/json2ddl.py b/xls2ddl/json2ddl.py
index e38ee7a..0bd8a13 100644
--- a/xls2ddl/json2ddl.py
+++ b/xls2ddl/json2ddl.py
@@ -34,6 +34,9 @@ def xls2ddl(xlsfile,dbtype):
 	if data is None:
 		print(xlsfile, 'not data return')
 		return
+	pri = data['summary'][0]['primary']
+	if isinstance(pri, str):
+		data['summary'][0]['primary'] = [pri]
 	tmpl = tmpls.get(dbtype.lower())
 	if tmpl is None:
 		raise Exception('%s database not implemented' % dbtype)