如果Client为空，我需要更新address_1表中的所有记录，但address_2不是。address_2。在这些情况下，我想将address_1移至UPDATE Client SET Address_1 = 'address1', address_2 = ''
WHERE client_id = 'client_id'
。这是我到目前为止的查询：
client_id但我没有传递package com.example.administrador.app3;
import android.Manifest;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Build;
import android.provider.Settings;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.util.HashMap;
public class MainActivity extends AppCompatActivity {
private TextView textView;
private LocationManager locationManager;
private LocationListener locationListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.textView);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
//textView
double latit = location.getLatitude();
double longit = location.getLongitude();
final String lat = String.valueOf(latit);
final String lng = String.valueOf(longit);
class AddCoord extends AsyncTask<Void,Void,String>{
ProgressDialog loading;
@Override
protected void onPreExecute(){
super.onPreExecute();
loading = ProgressDialog.show(MainActivity.this,"Adding...","Wait...",false,false);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
Toast.makeText(MainActivity.this, s, Toast.LENGTH_LONG).show();
}
@Override
protected String doInBackground(Void... v) {
HashMap<String,String> params = new HashMap<>();
params.put(Config.KEY_EMP_LAT,lat);
params.put(Config.KEY_EMP_LNG,lng);
RequestHandler rh = new RequestHandler();
String res = rh.sendPostRequest(Config.URL_ADD, params);
return res;
}
}
AddCoord ac = new AddCoord();
ac.execute();
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
};
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{
Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.INTERNET
}, 10 );
return;
}
}else{
locationManager.requestLocationUpdates("gps", 300000, 0, locationListener);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode){
case 10:
if(grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
locationManager.requestLocationUpdates("gps", 300000, 0, locationListener);
}
}
}
，而是想更新每条记录。
答案 0 :(得分：1)
您需要的查询是
UPDATE client SET address_1 = address_2, address_2 = ''
WHERE address_1 = '' AND address_2 != ''
在WHERE中，它会找到所有问题行，然后将address_2移至address_1并清空address_2
注意：确保您不会将空字符串''与NULL混淆。在DB2中，那些不一样。如果您的值实际为NULL，则您的查询必须为：
UPDATE client SET address_1 = address_2, address_2 = NULL
WHERE address_1 IS NULL AND address_2 IS NOT NULL