在以下活动中 - 用户必须输入已定义的字段。一旦输入完成，用户就可以编辑更改并保存。但是在我的应用程序中，条目已成功插入到数据库中，但在编辑相同的字段时，我得到一个非法的参数异常，即website_1列不存在，尽管我在数据库中检查列是否存在。提前感谢
注意：populateFields是我收到错误的方法。在活动开始时，调用populateField方法来填充字段。
public class Newform_Screen2_Likewebsite_edit extends Activity {
EditText w1,c1,w2,c2,w3,c3;
Button btn_save;
private String srowId;
DBAdapter dba;
SQLiteDatabase myDB;
private Context context;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.newform_screen2_websites);
dba=new DBAdapter(this);
context=Newform_Screen2_Likewebsite_edit.this;
final Intent intent = getIntent();
srowId=intent.getStringExtra("KEYROWID");
myDB=DBAdapter.openDatabase(context, DBAdapter.DATABASE_NAME);
w1=(EditText)findViewById(R.id.www1_web_id);
w2=(EditText)findViewById(R.id.www2_web_id);
w3=(EditText)findViewById(R.id.www3_web_id);
c1=(EditText)findViewById(R.id.color1_id);
c2=(EditText)findViewById(R.id.color2_id);
c3=(EditText)findViewById(R.id.color3_id);
btn_save=(Button)findViewById(R.id.btn_save_web);
populateFields();
btn_save.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
n2();
n1();
}
private void n2() {
dba = new DBAdapter(Newform_Screen2_Likewebsite_edit.this);
String s1=w1.getText().toString();
String s2=w2.getText().toString();
String s3=w3.getText().toString();
String s4=c1.getText().toString();
String s5=c2.getText().toString();
String s6=c3.getText().toString();
String updatequery = "UPDATE "+ DBAdapter.DATABASE_TABLE+ " SET ";
updatequery = updatequery + DBAdapter.KEY_WEBSITE_1+" = '" + s1 +"',";
updatequery = updatequery + DBAdapter.KEY_WEBSITE_2+" = '" + s2 + "',";
updatequery = updatequery + DBAdapter.KEY_WEBSITE_3+" = '" + s3 + "',";
updatequery = updatequery + DBAdapter.KEY_COLOR_1+" = '" + s4 + "',";
updatequery = updatequery + DBAdapter.KEY_COLOR_2+" = '" + s5 + "',";
updatequery = updatequery + DBAdapter.KEY_COLOR_3+" = '"+s6+"'";
updatequery = updatequery + " WHERE _id = '" + srowId + "';";
Log.v("updatequery-new-likewebsite-edit",updatequery);
try{
Log.v("test-2","update");
dba.open();
myDB.execSQL(updatequery);
}catch(NullPointerException e){
e.getMessage();
}finally{
Log.v("test-3","update");
if(myDB != null)myDB.close();
dba.close();
}
}
private void Log(String string) {
Log.i("Activity-check",""+string);
}
private void n1() {
Intent I = new Intent(Newform_Screen2_Likewebsite_edit.this,Newform_Screen2_edit.class);
I.putExtra("rowid", srowId);
startActivity(I);
}
});
}
private void populateFields() {
dba.open();
if (srowId != null) {
Log.v("rowid",srowId.toString());
long mRowId=Long.parseLong(srowId);
Cursor cur = dba.fetchSaleseditdetails(mRowId);
startManagingCursor(cur);
try{
Log.v("test populate","test populate");
w1.setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_WEBSITE_1)));
w2.setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_WEBSITE_2)));
w3.setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_WEBSITE_3)));
c1 .setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_COLOR_1)));
c2.setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_COLOR_2)));
c3.setText(cur.getString(cur.getColumnIndexOrThrow(DBAdapter.KEY_COLOR_3)));
}
catch(Exception e){
e.printStackTrace();
}
}
dba.close();
}
protected void onDestroy() {
super.onDestroy();
if (dba != null) {
dba.close();
}
if (myDB != null) {
myDB.close();
}
}
}
Logcat文件
02-22 10:49:29.717: W/System.err(20723): java.lang.IllegalArgumentException: column 'website_1' does not exist
02-22 10:49:29.717: W/System.err(20723): at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:302)
02-22 10:49:29.717: W/System.err(20723): at com.example.exa_sales_new.Newform_Screen2_Likewebsite_edit.populateFields(Newform_Screen2_Likewebsite_edit.java:135)
02-22 10:49:29.717: W/System.err(20723): at com.example.exa_sales_new.Newform_Screen2_Likewebsite_edit.onCreate(Newform_Screen2_Likewebsite_edit.java:48)
02-22 10:49:29.717: W/System.err(20723): at android.app.Activity.performCreate(Activity.java:5008)
02-22 10:49:29.717: W/System.err(20723): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
02-22 10:49:29.717: W/System.err(20723): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
02-22 10:49:29.717: W/System.err(20723): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
02-22 10:49:29.717: W/System.err(20723): at android.app.ActivityThread.access$600(ActivityThread.java:130)
02-22 10:49:29.717: W/System.err(20723): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
02-22 10:49:29.717: W/System.err(20723): at android.os.Handler.dispatchMessage(Handler.java:99)
02-22 10:49:29.717: W/System.err(20723): at android.os.Looper.loop(Looper.java:137)
02-22 10:49:29.717: W/System.err(20723): at android.app.ActivityThread.main(ActivityThread.java:4745)
02-22 10:49:29.717: W/System.err(20723): at java.lang.reflect.Method.invokeNative(Native Method)
02-22 10:49:29.717: W/System.err(20723): at java.lang.reflect.Method.invoke(Method.java:511)
02-22 10:49:29.717: W/System.err(20723): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
02-22 10:49:29.717: W/System.err(20723): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-22 10:49:29.717: W/System.err(20723): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
我认为您正在呼叫populateFields();来访问该列，但是
表尚未创建，这就是您获得“列的原因
'website_1'不存在“例外。
我强烈建议您查看SQLiteOpenHelper类来管理您的数据库。它将在内部处理何时创建数据库的架构或何时升级它。
下面是一个示例示例，它将为您提供有关如何升级数据库或执行alter query的一些信息。
public class OpenHelper extends SQLiteOpenHelper {
private final static int DB_VERSION = 2;
public TracksDB(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
final String CREATE_TBL =
"create table " + ANIMALS_TABLE +
" (_id integer primary key autoincrement, " +
"animal_name text not null, " +
"biography text not null);";
db.execSQL(CREATE_TBL);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (oldVersion < 2) {
final String ALTER_TBL =
"ALTER TABLE " + ANIMALS_TABLE +
" ADD COLUMN biography text not null;";
db.execSQL(ALTER_TBL);
}
}
}
有关升级数据库的详细信息，请参阅this link。
注意：
onCreate()只会在您第一次安装应用时调用，而onUpgrade()只会在已安装应用时调用，而您只是在更新它。希望这可以帮助您解决问题。