语言：c++,数据库：SQLite，问题：怎么把json格式的数据存进去。
node表是：(ID string,NODE string)
自己的处理：利用jsoncpp,做了一个插入函数
bool ObjManagement::AddJson(string JsonStr)
{
Json::Reader reader;
Json::Value json_object;
reader.parse(JsonStr, json_object, false);
string jsonID = json_object["ID"].toStyledString();
cout <<"解析到的jsonID:"<< jsonID << endl;
string jsonobj = json_object["AVP_LIST"].toStyledString();
string sqlInsert = "insert into node values(" + jsonID + ",\"" + jsonobj.c_str() +"\");";
cout << "拼接成的sqlInsert:" << sqlInsert << endl;
sqlite3_exec(pdb, sqlInsert.c_str(), 0, 0, &errMsg);
if (errMsg)
{
cout << "ObjManagement: \t sqlInsert:\t" << errMsg << endl;
return false;
}
return true;
}
main函数如下
int main()
{
DataBaseManagement *dbm = new DataBaseManagement();
ObjManagement *omg = new ObjManagement();
string strjson = "{\"ID\": \"6851950\", \"AVP_LIST\": [{\"ATTRIBUTE\": \"中文名\", \"VALUE\": \"吴映洁\"}]}";
cout<<strjson<<endl;
omg->AddJson(strjson);
dbm->CloseDb();
getchar();
}
得到的结果：
问题是：怎么能正确插入上述数据
uucomic
11 years, 7 months ago
Answers
我是这样解决的，我是把json写在一个文本里，，然后读取文本里的json，对它进行操作，没有报错，具体原因，我也不太清楚。主要的原因可能是我一开始那个json格式写的不规范，有错误吧。也特别感谢 @Windoze ,sql确实要注意用单引号的问题，我程序的其他模块有的地方就是没写成单引号而出错。
f.open("E:\\test.txt");
if (!f)
cout << "error";
//解析Json的方法
Json::Reader reader;
Json::Value json_object;
reader.parse(f, json_object, false);
f.close();
test.txt里的内容：
{"ID": "394557", "AVP_LIST": [{"ATTRIBUTE": "topic_equivalent_webpage", "VALUE": "http://baike.baidu.com/view/20338.htm"}, {"ATTRIBUTE": "name", "VALUE": "西汉"}, {"ATTRIBUTE": "entity_pv", "VALUE": "672"}, {"ATTRIBUTE": "entity_category", "VALUE": "年代,朝代"}, {"ATTRIBUTE": "国家领袖", "VALUE": "刘邦、刘彻、刘询"}, {"ATTRIBUTE": "主要民族", "VALUE": "汉族、匈奴、南越族"}, {"ATTRIBUTE": "政治体制", "VALUE": "君主专制政体"}, {"ATTRIBUTE": "货币", "VALUE": "汉五铢"}, {"ATTRIBUTE": "主要民族", "VALUE": "南越族"}, {"ATTRIBUTE": "国家领袖", "VALUE": "刘询"}, {"ATTRIBUTE": "文学体裁", "VALUE": "汉赋"}, {"ATTRIBUTE": "首都", "VALUE": "长安（今西安）"}, {"ATTRIBUTE": "简称", "VALUE": "汉"}, {"ATTRIBUTE": "国家领袖", "VALUE": "刘彻"}, {"ATTRIBUTE": "主要民族", "VALUE": "汉族"}, {"ATTRIBUTE": "主要宗教", "VALUE": "道教"}, {"ATTRIBUTE": "主要城市", "VALUE": "长安、宛、临淄、洛阳、邯郸"}, {"ATTRIBUTE": "主要城市", "VALUE": "长安"}, {"ATTRIBUTE": "所属洲", "VALUE": "亚洲"}, {"ATTRIBUTE": "时区", "VALUE": "东八区"}, {"ATTRIBUTE": "主要城市", "VALUE": "邯郸"}, {"ATTRIBUTE": "国家领袖", "VALUE": "刘邦"}, {"ATTRIBUTE": "国土面积", "VALUE": "1400/1040/2560万（说法不一）"}, {"ATTRIBUTE": "主要民族", "VALUE": "匈奴"}, {"ATTRIBUTE": "主要城市", "VALUE": "洛阳"}, {"ATTRIBUTE": "人口数量", "VALUE": "约6000万（公元2年）"}, {"ATTRIBUTE": "英文名称", "VALUE": "TheHanDynasty"}, {"ATTRIBUTE": "主要城市", "VALUE": "临淄"}, {"ATTRIBUTE": "中文名称", "VALUE": "西汉"}, {"ATTRIBUTE": "官方语言", "VALUE": "中原官话"}, {"ATTRIBUTE": "主要城市", "VALUE": "宛"}]}
zscbc
answered 11 years, 7 months ago
- SQL里的字符串要用单引号
- 你需要escape，也就是说，JSON里如果出现了单引号，你要把它变成两个单引号
template<typename Input, typename Output>
inline void SQL_escape(Input in, Output &out) {
if(*in=='\'') *out++='\'';
*out++=*in;
}
template<typename Input, typename Output>
inline void SQL_escape(Input start, Input stop, Output out)
{ for(Input i=start; i!=stop; ++i) SQL_escape(i, out); }
然后你就可以这么用：
std::string s="A JSON string with single quote(') inside";
std::string escaped;
SQL_escape(s.begin(), s.end(), std::back_inserter(escaped));
std::cout << "INSERT INTO node VALUES('"<< escaped << "')" << std::endl;
飞机是这样的
answered 11 years, 7 months ago