//lwu.h
class BDB
{
public:
Db db;
char *keyword[N];
private:
u_int32_t oFlags;
void close();
Dbt key[N],data[N];//表示最多只能有N对数据对

public:
BDB();
~BDB() { close(); }
char* get(int g);
xiugai(char* xindata,int x );
add(char* ndata,int a);
};

BDB :: BDB()
: db(NULL, 0),
oFlags(DB_CREATE)
{
int j;
for(j=0;j<N;j++)//keyword[]跟key[]
{
char tmp[100];
itoa(j,tmp,10);
keyword[j]=strcat(tmp,"keyword");
key[j].set_data(keyword[j]);
key[j].set_size(strlen(keyword[j]) + 1);
key[j].set_flags(DB_DBT_USERMEM);
}
try
{
db.open(NULL, // Transaction pointer
"bdb.db", // Database file name
NULL, // Optional logical database name
DB_BTREE, // Database access method
oFlags, // Open flags
0); // File mode (using defaults)
}
catch(DbException &e)
{
std::cerr << e.what() << std::endl;
}
catch(std::exception &e)
{
std::cerr << e.what() << std::endl;
}
}
void BDB::close()
{
try
{
db.close(0);
}
catch(DbException &e)
{
std::cerr << e.what() << std::endl;
}
catch(std::exception &e)
{
std::cerr << e.what() << std::endl;
}
}

char *BDB::get(int g)
{
key[g].set_flags(DB_DBT_USERMEM);

int rett= db.get(NULL, &key[g], &data[g], 0);
char *x=(char*)data[g].get_data();
//printf("db: %s and %s: data stored.\n", data[g].get_data(),keyword[g]);
return x;
}

BDB::xiugai(char* xindata,int x)
{
key[x].set_flags(DB_DBT_USERMEM);
int rettt=db.del(NULL, &key[x], 0);
data[x].set_data(xindata);
data[x].set_size(strlen(xindata) + 1);
data[x].set_flags(DB_DBT_USERMEM);

db.put(NULL, &key[x], &data[x], DB_NOOVERWRITE);
// printf("db: %s and %s: data stored.\n", data[x].get_data(),keyword[x]);
}
BDB::add(char* ndata,int a)

{
key[a].set_flags(DB_DBT_USERMEM);

//Dbt data[a](ndata, strlen(ndata) + 1);
data[a].set_data(ndata);
data[a].set_size(strlen(ndata) + 1);
data[a].set_flags(DB_DBT_USERMEM);
int ret=db.put(NULL, &key[a], &data[a], DB_NOOVERWRITE);

}

What is the problem exactly? Does your code sample compile?

If so and it is a runtime problem, what behavior do you expect? What
behavior do you see?

compiling was no error！I want to use "key[N],data[N]" to record N pare datas.But the code couldn't get it.