打开数据库
sqlite3 * db = [Database openDB];

sqlite3_stmt * stmt = nil;
NSString * sqlString = [NSString stringWithFormat:@"select * from Student where id = %d" , aID];
int result = sqlite3_prepare_v2(db, [sqlString UTF8String], -1, &stmt,NULL);
Student * student = nil;
if (result == SQLITE_OK) {
if (sqlite3_step(stmt) == SQLITE_ROW) {
int ID = sqlite3_column_int(stmt, 0);


const unsigned char * name = sqlite3_column_text(stmt, 1);

const unsigned char * gender = sqlite3_column_text(stmt ,2);
int age = sqlite3_column_int(stmt, 3);

int lenght = sqlite3_column_bytes(stmt, 4);

const void * photo = sqlite3_column_blob(stmt, 4);

NSData * photoData = [NSData dataWithBytes:photo length:lenght];

UIImage * p_w_picpath = [UIImage p_w_picpathWithData:photoData];

student = [[Student alloc]init];
student.ID = ID;
student.name = [NSString stringWithUTF8String:(const char *)name];
student.gender = [NSString stringWithUTF8String:(const char *)gender];
student.age = age;

student.photo = p_w_picpath;


}
}

sqlite3_finalize(stmt);
[Database closeDB];