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DBHomework/old_src/doRemoveBook.cpp
2017-12-28 18:18:44 +08:00

125 lines
2.8 KiB
C++

#include "bs_util.h"
#include "MySQLTransaction.h"
using namespace std;
int main()
{
Request req;
Session se(req);
Response res;
json j;
auto jsonfail=[&](int errcode,const std::string& dtl="")
{
jsonfail_func(j,errcode,dtl);
};
do
{
if(!se.isReady())
{
jsonfail(err_session);
break;
}
if(se.getUser().empty())
{
jsonfail(err_need_login);
break;
}
if(req.requestMethod!="POST")
{
jsonfail(err_method_not_supported);
break;
}
postval(id);
int id_real=ParseInt(id);
if(id_real<0)
{
jsonfail(err_parameter,"Failed to parse id");
break;
}
startdb();
Transaction ts(conn);
/// Check Permission
int permission_level=-1;
if(conn.exec(make_str("select permission_level from bs_user where username='",
se.getUser(),
"'"),
SQLParseInt(permission_level))<0)
{
jsonfail(err_sql,"Step 1");
break;
}
if(permission_level<0)
{
jsonfail(err_general,"Failed to check Permission");
break;
}
if(permission_level>=3)
{
jsonfail(err_permission_denied);
break;
}
/// Check if the book info can be removed.
/// count_val: Count of books with class_id={ID} and status is borrowed (0)
int count_val=-1;
if(conn.exec(make_str("select count(book_id) from bs_bookstatus where class_id=",
id_real,
" and status=0"),
SQLParseInt(count_val))<0)
{
jsonfail(err_sql,"Step 2");
break;
}
if(count_val<0)
{
jsonfail(err_data,"Failed to get book id data");
break;
}
if(count_val!=0)
{
jsonfail(err_data,make_str("Cannot remove book. Still ",count_val," books borrowed."));
break;
}
if(conn.exec(make_str("delete from bs_borrow where book_id in (select book_id from bs_bookstatus where class_id=",id_real),nullptr)<0)
{
jsonfail(err_sql,"Step 3");
}
if(conn.exec(make_str("delete from bs_bookstatus where class_id=",id_real),nullptr)<0)
{
jsonfail(err_sql,"Step 4");
break;
}
if(conn.exec(make_str("delete from bs_book where class_id=",id_real),nullptr)<0)
{
jsonfail(err_sql,"Step 5");
break;
}
ts.commit();
j["success"]=1;
}
while(0);
se.writeToResponse(res);
res.content.append(j.dump());
return 0;
}