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Android 由于java.lang.IllegalArgumentException:column'_id';不存在_Android_Sqlite_Crash_Cursor - Fatal编程技术网

Android 由于java.lang.IllegalArgumentException:column'_id';不存在

Android 由于java.lang.IllegalArgumentException:column'_id';不存在,android,sqlite,crash,cursor,Android,Sqlite,Crash,Cursor,每当我启动我的应用程序时,我都会得到一个java.lang.IllegalArgumentException:列'\u id'在我的日志中不存在错误。我已经创建了列“\u id”,但它仍然抛出这个。以下是我的主要.java: package com.gantt.shoppinglist; import android.app.Dialog; import android.app.ListActivity; import android.database.Cursor; import andro

每当我启动我的应用程序时,我都会得到一个
java.lang.IllegalArgumentException:列'\u id'在我的日志中不存在
错误。我已经创建了列
“\u id”
,但它仍然抛出这个。以下是我的主要.java:

package com.gantt.shoppinglist;

import android.app.Dialog;
import android.app.ListActivity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

public class ShoppingList extends ListActivity {

    private DataHelper DataHelper;
    /** Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        DataHelper = new DataHelper(this);

        Cursor c = (Cursor) DataHelper.selectAll();
        long id = c.getLong(c.getColumnIndex("_id"));
        startManagingCursor(c);

        ListView lv = (ListView) findViewById(android.R.id.list);

        String[] from = new String[] { com.gantt.shoppinglist.DataHelper.getDatabaseName() };
        int[] to = new int[] { android.R.id.text1 };

        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
                android.R.layout.simple_list_item_1, c, from, to);       
        lv.setAdapter(adapter);

        Button button1main = (Button) findViewById(R.id.add);
        button1main.setOnClickListener(new OnClickListener()  {
            @Override
            public void onClick(View v)  {
            final Dialog additem = new Dialog(ShoppingList.this);
            additem.setContentView(R.layout.maindialog);
            final EditText et = (EditText)additem.findViewById(R.id.edittext);
            additem.setTitle("Type your item");
            additem.setCancelable(true);
            et.setHint("Type the name of an item...");

            Button button = (Button) additem.findViewById(R.id.cancel);
            button.setOnClickListener(new OnClickListener()  {
                @Override
                public void onClick(View v)  {
                    additem.dismiss();
                }
            });
            additem.show();

            Button ok = (Button) additem.findViewById(R.id.ok);
            ok.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    final String text = et.getText().toString();
                    additem.dismiss();
                    et.setText("");
                }
            });
       }
        });
    }
}
以下是我的DataHelper类:

package com.gantt.shoppinglist;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteStatement;
import android.util.Log;

public class DataHelper {

       private static final String DATABASE_NAME = "items.db";
       private static final int DATABASE_VERSION = 1;
       private static final String TABLE_NAME = "table1";
       public static final String KEY_ROWID = "_id";

       private Context context;
       private SQLiteDatabase db;

       private SQLiteStatement insertStmt;
       private static final String INSERT = "insert into " 
          + TABLE_NAME + "(name) values (?)";

       public DataHelper(Context context) {
          this.context = context;
          OpenHelper openHelper = new OpenHelper(this.context);
          this.db = openHelper.getWritableDatabase();
          this.insertStmt = this.db.compileStatement(INSERT);
       }

       public long insert(String name) {
          this.insertStmt.bindString(1, name);
          return this.insertStmt.executeInsert();
       }

       public void deleteAll() {
          this.db.delete(TABLE_NAME, null, null);
       }

       public Cursor selectAll() {
          List<String> list = new ArrayList<String>();
          Cursor cursor = this.db.query(TABLE_NAME, new String[] { "name" }, 
            null, null, null, null, "name desc");
          if (cursor.moveToFirst()) {
             do {
                list.add(cursor.getString(0)); 
             } while (cursor.moveToNext());
          }
          if (cursor != null && !cursor.isClosed()) {
             cursor.close();
          }
          return cursor;
       }

       public static String getDatabaseName() {
        return DATABASE_NAME;
    }

    private static class OpenHelper extends SQLiteOpenHelper {

          OpenHelper(Context context) {
             super(context, getDatabaseName(), null, DATABASE_VERSION);
          }

          @Override
          public void onCreate(SQLiteDatabase db) {
              db.execSQL("CREATE TABLE " + TABLE_NAME + "(id INTEGER PRIMARY KEY, name TEXT");

          }

          @Override
          public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
             Log.w("Example", "Upgrading database, this will drop tables and recreate.");
             db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
             onCreate(db);
          }
       }
    }
package com.gantt.shoppinglist;
导入java.util.ArrayList;
导入java.util.List;
导入android.content.Context;
导入android.database.Cursor;
导入android.database.sqlite.SQLiteDatabase;
导入android.database.sqlite.SQLiteOpenHelper;
导入android.database.sqlite.SQLiteStatement;
导入android.util.Log;
公共类DataHelper{
私有静态最终字符串数据库\u NAME=“items.db”;
私有静态最终int数据库_VERSION=1;
私有静态最终字符串表\u NAME=“table1”;
公共静态最终字符串键_ROWID=“_id”;
私人语境;
专用数据库数据库;
私有SQLiteStatement insertStmt;
私有静态最终字符串INSERT=“插入到”
+表_NAME+“(NAME)值(?);
公共DataHelper(上下文){
this.context=上下文;
OpenHelper OpenHelper=新的OpenHelper(this.context);
this.db=openHelper.getWritableDatabase();
this.insertStmt=this.db.compileStatement(INSERT);
}
公共长插入(字符串名称){
this.insertStmt.bindString(1,名称);
返回此.insertStmt.executeInsert();
}
public void deleteAll(){
this.db.delete(表名称,null,null);
}
公共游标selectAll(){
列表=新的ArrayList();
Cursor Cursor=this.db.query(表名,新字符串[]{“NAME”},
空,空,空,空,“名称描述”);
if(cursor.moveToFirst()){
做{
list.add(cursor.getString(0));
}while(cursor.moveToNext());
}
if(cursor!=null&!cursor.isClosed()){
cursor.close();
}
返回光标;
}
公共静态字符串getDatabaseName(){
返回数据库名称;
}
私有静态类OpenHelper扩展了SQLiteOpenHelper{
OpenHelper(上下文){
super(上下文,getDatabaseName(),null,数据库版本);
}
@凌驾
public void onCreate(SQLiteDatabase db){
db.execSQL(“创建表”+表名称+”(id整数主键,名称文本”);
}
@凌驾
public void onUpgrade(SQLiteDatabase db,int-oldVersion,int-newVersion){
w(“示例”,“升级数据库,这将删除表并重新创建”);
db.execSQL(“如果存在删除表”+表名称);
onCreate(db);
}
}
}

嗯,不确定是否粘贴错误,但:

 DataHelper = new DataHelper(this);
 Cursor c = (Cursor) DataHelper.selectAll();
错误。您需要将其声明给一个对象,并对初始化的数据库对象调用您的方法:

 DataHelper dataHelper = new DataHelper(this);
 Cursor c = (Cursor) dataHelper.selectAll();
哦,糟糕,您刚刚用大写字母D声明了变量名,这不是推荐的,也不是标准的java编码风格


我有一个类似的问题-我认为这是一个必须“选择”(或“选择为”)一个称为
\u id
的东西的情况,因为
SimpleCursorAdapter
需要它

从:

处理内容URI ID

按照惯例,提供程序通过以下方式提供对表中单个行的访问: 接受一个内容URI,该URI在 按照惯例,提供者将ID值与表的
\u ID
列,并对匹配的行执行请求的访问

此约定促进了应用程序访问的通用设计模式 提供商。应用程序对提供商进行查询并显示 使用
光标或适配器在
列表视图中生成
光标
。定义 of
CursorAdapter
要求
光标中的一列为
\u ID

在我的例子中,我的表中有一个名为“oid”的自动编号列,因此我将SELECT命令改为(例如)

这为我解决了这个问题

编辑以显示更广泛的代码

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.channel_selector);

    GridView channel_selector_grid = (GridView) findViewById(R.id.channel_grid);
    sca = getGuideAdapter();
    channel_selector_grid.setAdapter(sca);
}

public SimpleCursorAdapter getGuideAdapter() {
    SimpleCursorAdapter adapter = null;
    SQLiteDatabase db = SQLiteDatabaseHelper.getReadableDatabase();
    Cursor cursor = db.rawQuery("SELECT DISTINCT oid as _id, name, number FROM CHAN_TABLE ORDER BY number", null);
    if (cursor.moveToFirst()) {
        String[] columnNames = { "name" };
        int[] resIds = { R.id.channel_name };
        adapter = new SimpleCursorAdapter(this, R.layout.channel_selector_item, cursor, columnNames, resIds);
    }
    return adapter; 
}

您是否确保卸载并重新安装该应用程序,以便您的数据库具有新创建的_id列?或者可能将其包含在升级方法中?类似地,如果使用managedQuery,则必须在字符串[]中包含“_id”数组第二个参数。请注意!我在调用日志中遇到了相同的错误,必须在字段中添加android.provider.CallLog.Calls.\u ID!有效。@Squonk有没有办法更改用于UID的适配器列?@Squonk回答是正确的,与缺少“\u ID”列有关。值得注意的是,\u ID列名的大小写很重要,应该降低ase(至少我发现了)
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.channel_selector);

    GridView channel_selector_grid = (GridView) findViewById(R.id.channel_grid);
    sca = getGuideAdapter();
    channel_selector_grid.setAdapter(sca);
}

public SimpleCursorAdapter getGuideAdapter() {
    SimpleCursorAdapter adapter = null;
    SQLiteDatabase db = SQLiteDatabaseHelper.getReadableDatabase();
    Cursor cursor = db.rawQuery("SELECT DISTINCT oid as _id, name, number FROM CHAN_TABLE ORDER BY number", null);
    if (cursor.moveToFirst()) {
        String[] columnNames = { "name" };
        int[] resIds = { R.id.channel_name };
        adapter = new SimpleCursorAdapter(this, R.layout.channel_selector_item, cursor, columnNames, resIds);
    }
    return adapter; 
}