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原标题:Find near locations with SQLite and Android

我在“我”数据库中有一个数据表,其中载有关于长度、纬度和描述的信息。 鉴于某个地点,我要从该地点接近距离(10个区)的所有行各行。

This is how data is loaded:

values.put(LONGITUD_COLUMN,  (int) (-64.14802 * 1E6));
values.put(LATITUD_COLUMN, (int) (-31.36498 * 1E6));

到目前为止,这是我法典中的内容:

private int cuadras = (int)(-0.02 * 1E6) ; //10 blocks aprox, I guess
private int current_latitude = 0;
private int current_longitude = 0;

装载(来自Listener地点):

public void onLocationChanged(Location location) {
 current_latitude = (int) (location.getLatitude() * 1E6);
 current_longitude = (int) (location.getLongitude() * 1E6);
}

卡库特人问:

String sql = "LATITUD_COLUMN > (" + (current_latitude + cuadras) + ") AND "
+ "LATITUD_COLUMN < (" + (current_latitude - cuadras) +") AND "
+ "LONGITUD_COLUMN > ("+ (current_longitude - cuadras) +") AND "
+ "LONGITUD_COLUMN < ("+ (current_longitude + cuadras) +")";

结果是:

LATITUD_COLUMN > (-31398170) AND LATITUD_COLUMN < (-31358170) AND LONGITUD_COLUMN > (-64132838) AND LONGITUD_COLUMN < (-64172838)

问题完全没有结果,我的问题是,我如何质疑把所有地点带到我目前地点的数据基?

感谢!

最佳回答

你看来有过你,而且——混合:

String sql = "LATITUD_COLUMN > (" + (current_latitude + cuadras) + ") AND "
+ "LATITUD_COLUMN < (" + (current_latitude - cuadras) +") AND "
+ "LONGITUD_COLUMN > ("+ (current_longitude - cuadras) +") AND "
+ "LONGITUD_COLUMN < ("+ (current_longitude + cuadras) +")";

应当

String sql = "LATITUD_COLUMN > (" + (current_latitude + cuadras) + ") AND "
+ "LATITUD_COLUMN < (" + (current_latitude - cuadras) +") AND "
+ "LONGITUD_COLUMN > ("+ (current_longitude + cuadras) +") AND "
+ "LONGITUD_COLUMN < ("+ (current_longitude - cuadras) +")";

LONGITUD_COLUMN > (-64132838) 和LONGITUD_COLUMN < (-64172838)始终不实。

问题回答

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