From 60b1704516c3af6ff969d81f359cf310ad43a2e0 Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Tue, 3 Jan 2017 14:17:17 +0800
Subject: [PATCH] don't panic but return nil when query dialect

---
 dialect.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dialect.go b/dialect.go
index 7bedc27d..8c950da0 100644
--- a/dialect.go
+++ b/dialect.go
@@ -290,6 +290,7 @@ var (
 	dialects = map[DbType]func() Dialect{}
 )
 
+// RegisterDialect register database dialect
 func RegisterDialect(dbName DbType, dialectFunc func() Dialect) {
 	if dialectFunc == nil {
 		panic("core: Register dialect is nil")
@@ -297,6 +298,10 @@ func RegisterDialect(dbName DbType, dialectFunc func() Dialect) {
 	dialects[dbName] = dialectFunc // !nashtsai! allow override dialect
 }
 
+// QueryDialect query if registed database dialect
 func QueryDialect(dbName DbType) Dialect {
-	return dialects[dbName]()
+	if d, ok := dialects[dbName]; ok {
+		return d()
+	}
+	return nil
 }