无法从C ++在MySQL中插入数据

Question

Am trying to insert data from C++ console application in mysql database table.

Am having table:

CREATE TABLE `Emp` (
  `empId` int(11) NOT NULL AUTO_INCREMENT,
  `empName` varchar(50) NOT NULL,
  PRIMARY KEY (`empId`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1

Now when I try to insert data, I get success message, but when I cross check it in the database, I am not getting any result.

Here's what I give the input to insert:

crazydeveloper@crazydeveloper:~/Desktop$ g++ InsertInMysql.cpp -o InsertInMysql -L /usr/include/mysql -lmysqlclient -I /usr/include/mysql
crazydeveloper@crazydeveloper:~/Desktop$ ./InsertInMysql

Please Enter Your Name: 
Maddy
Connection Established Successfully.......
Connection Established Successfully.......
Your Name is Maddy
INSERT INTO Emp VALUES('Maddy')
Success....

Update: When I insert 2 words for empName , only 1st word gets inserted:

here's the query

Please Enter Your Name: 
Brett Lee
Connection Established Successfully.......
Connection Established Successfully.......
Your Name is Brett
INSERT INTO Emp(empName) VALUES('Brett')

Here's my C++ source code:

#include <iostream>
#include <mysql.h>
#include <my_global.h>

#define SERVER "localhost"
#define USERNAME "root"
#define PASSWORD "root"
#define DATABASE "Test"

using namespace std;

int main() {

    string empFirstName, query;
    int res;

    cout << "\nPlease Enter Your Name: " << endl;
    getline(cin, empFirstName);

    MYSQL *connect;
    connect = mysql_init(NULL);

    if (connect){
        cout << "Connection Established Successfully......." << endl;
    }

    connect = mysql_real_connect(connect, SERVER, USERNAME, PASSWORD, DATABASE, 0,NULL,0);

    if (connect){
        cout << "Connection Established Successfully......." << endl;
        cout << "Your Name is " << empFirstName << endl;
    }

    query = "INSERT INTO Emp VALUES('"+empFirstName+"')";

    cout << query << endl;

    if (mysql_query(connect, query.c_str())){
        cout << "Success.... \n" << endl;
    }   

    mysql_close (connect);

    return 0;   
}

---

Bug Found

Just found the error: When I was not giving the column name empName in the query, the success message was printed. And now when I am giving the column name empName , the success message is not printed.

Query to insert:

// prints success message
query = "INSERT INTO Emp VALUES('"+empFirstName+"')";

Query to insert(after updating):

// does not prints success message
query = "INSERT INTO Emp(empName) VALUES('"+empFirstName+"')";

Kindly guide me where am I making mistake. Thanks.

Answer 1

Your table structure says it has a primary key empId as the first column.

So when you write query as

INSERT INTO Emp VALUES ('first name')

The value will refer to the column empId and the query will fail.

You will need to explicitly specify the column names in this situation , something as

INSERT INTO Emp (empName) VALUES ('first name')

Now mysql knows that the value is for the column empName.