proc c++连接oracle

EXEC SQL BEGIN DECLARE SECTION;

struct datatable
{
    int id;
    char name[30];
} data;
EXEC SQL END DECLARE SECTION;

//#define SQLCA_STORAGE_CLASS extern  //增加该行报错
EXEC SQL INCLUDE connect_oracle.h;
#include <sqlca.h>
#include <iostream>
using namespace std;

EXEC SQL BEGIN DECLARE SECTION;
   char* pid ="scott/tiger@orcl";
   int ids;
EXEC SQL END DECLARE SECTION;


int connectdb(){
    EXEC SQL CONNECT :pid;
    if(sqlca.sqlcode!=0){
        cout<< "connect err "<<sqlca.sqlcode<<endl;
        return sqlca.sqlcode;;
    }
    cout<< "connect ok"<<endl;
    return sqlca.sqlcode;;
}

int selectData(datatable& data){
    EXEC SQL 
    SELECT * INTO :data FROM TEST where id=1;
    return sqlca.sqlcode;
}

int insertData(datatable& data){
    exec sql 
     insert into test(id,name) values (:data.id,:data.name);
    if(sqlca.sqlcode!=0){
        cout<< "insert err "<<sqlca.sqlcode<<endl;
        return sqlca.sqlcode;;
    }
    exec sql commit;
    return sqlca.sqlcode;
}

int updateData(datatable& data){
    exec sql 
     update test set name=:data.name where id=:data.id;
    if(sqlca.sqlcode!=0){
        cout<< "update err "<<sqlca.sqlcode<<endl;
        return sqlca.sqlcode;;
    }
    exec sql commit;
    return sqlca.sqlcode;
}

int deleteData(int id){
    ids =id;
    exec sql
     delete from test where id=:ids;
    if(sqlca.sqlcode!=0){
        cout<< "delete err "<<sqlca.sqlcode<<endl;
        return sqlca.sqlcode;;
    }
    exec sql commit;
    return sqlca.sqlcode;
}

void disconnect(){
    EXEC SQL COMMIT RELEASE;
}

#define SQLCA_STORAGE_CLASS extern

#include <iostream>
#include <sqlca.h>
using namespace std;


struct datatable
{
    int id;
    char name[30];
};

extern int connectdb();
extern int selectData(datatable& data);
extern int insertData(datatable& data);
extern int updateData(datatable& data);
extern int deleteData(int id);
extern void disconnect();


int main() {
    connectdb();
    datatable da;
    selectData(da);

    datatable insertdata;
    insertdata.id = 2;

    strcpy(insertdata.name, "bbb");
    insertData(insertdata);

    strcpy(insertdata.name, "ccc");
    updateData(insertdata);

    deleteData(2);


    disconnect();
    return 0;
}