C ++ MySQL插入数据库

Question

this is my code i am trying to insert ma in sma inside my data base but error occur as: too many arguments to function 'int mysql_query(MYSQL*,const char*)' note declared in mysql.h line in mysql.h : int STDCALL mysql_query(MYSQL *mysql, const char *q);

while(true)
    {
        mysql_query(conn, " select close, id from fivemin order by id DESC LIMIT 5 ");
    result = mysql_store_result(conn);
    num_fields = mysql_num_fields(result);
    float sum = 0;
    while((row=mysql_fetch_row(result)))
        {
                 sum += atof(row[0]);
                 last_id = atoi(row[1]);

        }
    float ma;
    ma=sum/5.0;
    if(previous_last_id != last_id)
        {
        cout << "Simple moving Average: " << ma << endl;
        previous_last_id = last_id;
        }

     mysql_query(conn,("insert into sma values('%f')"),ma);
    Sleep(1000);
}

Answer 1

mysql_query(conn,("insert into sma values('%f')"),ma) has three arguments.

You need to format your string prior to call mysql_query.

Example:

char str[80];
sprintf(str, "insert into sma values('%f')", ma);
mysql_query(conn, str);