fix demo bug

Author: li6185377

LKDBHelper/LKAppDelegate.m

@@ -52,11 +52,8 @@ -(void)test
 {
     addText(@"示例 开始 example start \n\n");
 
-    NSString* dbpath = [NSHomeDirectory() stringByAppendingPathComponent:@"asd/asd.db"];
     //清空数据库
-//  LKDBHelper* globalHelper = [LKDBHelper getUsingLKDBHelper];
-    
-    LKDBHelper* globalHelper = [[LKDBHelper alloc]initWithDBPath:dbpath];
+    LKDBHelper* globalHelper = [LKTest getUsingLKDBHelper];
     [globalHelper dropAllTable];
 
     //创建表  会根据表的版本号  来判断具体的操作 . create table need to manually call

LKDBHelper/LKTestModels.m

@@ -37,6 +37,19 @@ +(void)initialize
     //[[self getUsingLKDBHelper] createTableWithModelClass:self];
 }
 
+//重载可以选择 使用的LKDBHelper
++(LKDBHelper *)getUsingLKDBHelper
+{
+    static LKDBHelper* db;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        NSString* dbpath = [NSHomeDirectory() stringByAppendingPathComponent:@"asd/asd.db"];
+        db = [[LKDBHelper alloc]initWithDBPath:dbpath];
+    });
+    return db;
+}
+
+
 // 将要插入数据库
 +(BOOL)dbWillInsert:(NSObject *)entity
 {
@@ -148,6 +161,10 @@ +(LKTableUpdateType)tableUpdateForOldVersion:(int)oldVersion newVersion:(int)new
 
 
 @implementation LKTestForeign
++(LKDBHelper *)getUsingLKDBHelper
+{
+    return [LKTest getUsingLKDBHelper];
+}
 +(NSString *)getPrimaryKey
 {
     return @"addid";