02-22 11:43:04.858: ERROR/AndroidRuntime(18335): java.lang.RuntimeException: Unable to start activity ComponentInfo{android.Database/android.Database.projects}: android.database.sqlite.SQLiteException: no such column: _id: , while compiling: SELECT _id, Name, Comment, projects
这是我的发布活动：
package android.Database;
import android.app.Activity;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class projectsDatabase extends Activity {
/** Called when the activity is first created. */
SQLiteDatabase myDB = null;
final static String MY_DB_NAME ="projectsDatabase";
final static String MY_DB_TABLE = "projects";
static final int MENU_PROJECTS = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
onCreateDBAndDBTabled();
setContentView(R.layout.main);
}
private void onCreateDBAndDBTabled(){
myDB = this.openOrCreateDatabase(MY_DB_NAME, MODE_PRIVATE, null);
myDB.execSQL("CREATE TABLE IF NOT EXISTS " + MY_DB_TABLE
+ " ( _id integer primary key autoincrement,"+
"Name varchar(100),"+
"Comment varchar(128),"+
"BookingDetails varchar(255),"+
"ProjectKind integer(3))"
+";");
}
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, MENU_PROJECTS, 0, R.string.menuProjects)
.setShortcut('1', 'f')
.setIcon(R.drawable.icon);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()) {
case MENU_PROJECTS:
Intent iProjects= new Intent(this, projects.class);
startActivity(iProjects);
return true;
}
return false;
}
}
这是我想在点击菜单按钮时启动的活动：
package android.Database;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.SimpleCursorAdapter.ViewBinder;
import android.widget.TextView;
public class projects extends ListActivity {
SQLiteDatabase myDB = null;
static final int MENU_NEW_PROJECT = 0;
public void onCreate(Bundle icicle){
super.onCreate(icicle);
myDB = this.openOrCreateDatabase(projectsDatabase.MY_DB_NAME, MODE_PRIVATE, null);
Cursor c = myDB.rawQuery("SELECT _id, ColumnName, ColumnComment, " + projectsDatabase.MY_DB_TABLE + ";", null);
startManagingCursor(c);
SimpleCursorAdapter adapter = new SimpleCursorAdapter (this,
android.R.layout.simple_list_item_1,
c,
new String[] {"_id"},
new int []{android.R.id.text1});
adapter.setViewBinder (new ViewBinder (){
@Override
public boolean setViewValue(View view, Cursor theCursor, int column){
String ColumnName = theCursor.getString(1);//Name
String ColumnComment = theCursor.getString(2);//Comment
((TextView)view).setText(ColumnName + "," + ColumnComment);
return true;
}
});
this.setListAdapter(adapter);
}
@Override
protected void onListItemClick(ListView l, View v, int position, long _id){
super.onListItemClick(l, v, position, _id);
Intent i = new Intent(this, projects_New.class);
i.putExtra("_id", _id);
this.startActivity(i);
}
public boolean onCreateOptionsMenu(Menu menu){
super.onCreateOptionsMenu(menu);
menu.add(0, MENU_NEW_PROJECT, 0, R.string.menuNewProject)
.setShortcut('1', 'n')
.setIcon(android.R.drawable.ic_menu_add);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()){
case MENU_NEW_PROJECT:
Intent iProjects_New = new Intent (this, projects_New.class);
startActivity (iProjects_New);
return true;
}
return false;
}
}
我真的希望你能再次帮助我;）
-------------------------------------------- Edit-- ----------------------------------------- 现在我可以保存数据，但无法从我的listview中选择任何内容...这里是我的projects_new.class的代码：
package android.Database;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
public class projects_New extends Activity{
SQLiteDatabase myDB = null;
static final int MENU_INSERT_PROJECT = 0;
static final int MENU_UPDATE_PROJECT = 0;
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.projects_new);
Spinner s1 = (Spinner) findViewById(R.id.cb_ProjectKind);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this,
R.array.ProjectKind,
android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s1.setAdapter(adapter);
if(getIntent().hasExtra("_id") == true){
long l = getIntent().getExtras().getLong("_id");
myDB = this.openOrCreateDatabase(projectsDatabase.MY_DB_NAME, MODE_PRIVATE, null);
Cursor myCursor = myDB.rawQuery("SELECT _id, ColumnName, ColumnComment, ColumnBookingDetails, ColumnProjectKind FROM"
+ projectsDatabase.MY_DB_TABLE + "WHERE _id = " +l+ "", null);
startManagingCursor(myCursor);
int ColumnName = myCursor.getColumnIndex("ColumnName");
int ColumnComment = myCursor.getColumnIndex("ColumnComment");
int ColumnBookingDetails = myCursor.getColumnIndex("ColumnBookingDetails");
int ColumnProjectKind = myCursor.getColumnIndex("ColumnProjectKind");
myCursor.moveToFirst();
if (myCursor != null) {
if(myCursor.isFirst()){
EditText eName = (EditText)findViewById(R.id.ed_Name);
eName.setText(myCursor.getString(ColumnName));
EditText eComment = (EditText)findViewById(R.id.ed_Comment);
eComment.setText(myCursor.getString(ColumnComment));
EditText eBookingDetails = (EditText)findViewById(R.id.ed_BookingDetails);
eBookingDetails.setText (myCursor.getString(ColumnBookingDetails));
Spinner sProjectKind = (Spinner)findViewById(R.id.cb_ProjectKind);
sProjectKind.setSelection(myCursor.getInt(ColumnProjectKind), true);
}
}
}
}
public boolean onCreateOptionsMenu(Menu menu){
super.onCreateOptionsMenu(menu);
if(getIntent().hasExtra("_id")== true)
{
menu.add(0,MENU_UPDATE_PROJECT, 0, R.string.menuUpdate)
.setShortcut('1', 's')
.setIcon(android.R.drawable.ic_menu_save);
}
else
{
menu.add(0, MENU_INSERT_PROJECT, 0, R.string.menuInsert)
.setShortcut('1', 's')
.setIcon(android.R.drawable.ic_menu_save);
}
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()){
case MENU_INSERT_PROJECT:
EditText Name = (EditText)findViewById(R.id.ed_Name);
EditText Comment = (EditText)findViewById(R.id.ed_Comment);
EditText BookingDetails = (EditText)findViewById(R.id.ed_BookingDetails);
Spinner ProjectKind = (Spinner)findViewById(R.id.cb_ProjectKind);
int i = ProjectKind.getSelectedItemPosition();
if(Name.length()!= 0)
{
myDB = this.openOrCreateDatabase(projectsDatabase.MY_DB_NAME, MODE_PRIVATE, null);
if(getIntent().hasExtra("id")== true)//update
{
long l = getIntent().getExtras().getLong("_id");
myDB.execSQL("UPDATE "+ projectsDatabase.MY_DB_TABLE+" SET "+
"name = '"+Name.getText().toString()+"', "+
"Comment = '"+Comment.getText().toString()+"', "+
"BookingDetails ='"+BookingDetails.getText().toString()+"', "+
"ProjectKind ='"+i+"', "+
"WHERE _id = "+l+";");
}
else //insert
{
myDB.execSQL("INSERT INTO "+ projectsDatabase.MY_DB_TABLE +"(Name, Comment, BookingDetails, ProjectKind)"
+"VALUES ('"+Name.getText().toString()+"', "+
"'"+Comment.getText().toString()+"', "+
"'"+BookingDetails.getText().toString()+"', "+
"'"+i+"')");
}
finish();
return true;
}
else
{
Toast toast = Toast.makeText(this, "Please enter a name for this Project!" , Toast.LENGTH_SHORT);
toast.show();
}
}
return false;
}
}
非常感谢您的所有努力和帮助：）
答案 0 :(得分：1)
在您的Projects类中，您定义了以下行
Cursor c = myDB.rawQuery("SELECT _id, ColumnName,
ColumnComment, " + projectsDatabase.MY_DB_TABLE + ";", null);
因为它说，你的表中没有colunm _id ，所以请检查_id是否是表中的一列。 请确保clolun _id存在与否