sqlite数据查询速度慢的可能原因，sqlite数据查询
1.返回数据库字段信息与要查询数据库的数据字段不一致：
如下例：返回的字段少个IMGURL
String where = String::format("%s='%s'", AppBean::APPID().string(), appid.string());
DbResolver* p = DbResolver::getInstance();
if (p != NULL) {
StringArray pro(2);
pro.replaceAt(AppBean::PACKAGENAME(), 0);
pro.replaceAt(AppBean::APPNAME(), 1);
AutoCursor cursor = p->query(AppBean::DOWNLOAD_TABLE_NAME(), pro, where, StringArray(0), "");
if (cursor->moveToFirst()) {
String pkg = cursor->getString(cursor->getColumnIndex(AppBean::PACKAGENAME()));
String appname = cursor->getString(cursor->getColumnIndex(AppBean::APPNAME()));
String imageUrl = cursor->getString(cursor->getColumnIndex(AppBean::IMGURL()));
Demand d = NotificationDelegate::createDemand(appname, pkg, imageUrl, "", NotificationDelegate::STATUS_WAITDOWNLOAD, NotificationDelegate::PARAM_CANCEL);
mpContext->invokeDelegate(&d);
}
}
正确方式应为：
String where = String::format("%s='%s'", AppBean::APPID().string(), appid.string());
DbResolver* p = DbResolver::getInstance();
if (p != NULL) {
StringArray pro(3);
pro.replaceAt(AppBean::PACKAGENAME(), 0);
pro.replaceAt(AppBean::APPNAME(), 1);
pro.replaceAt(AppBean::IMGURL(), 2);
AutoCursor cursor = p->query(AppBean::DOWNLOAD_TABLE_NAME(), pro, where, StringArray(0), "");
if (cursor->moveToFirst()) {
String pkg = cursor->getString(cursor->getColumnIndex(AppBean::PACKAGENAME()));
String appname = cursor->getString(cursor->getColumnIndex(AppBean::APPNAME()));
String imageUrl = cursor->getString(cursor->getColumnIndex(AppBean::IMGURL()));
Demand d = NotificationDelegate::createDemand(appname, pkg, imageUrl, "", NotificationDelegate::STATUS_WAITDOWNLOAD, NotificationDelegate::PARAM_CANCEL);
mpContext->invokeDelegate(&d);
}
}