'_id'不存在，尽管ID列已更改为_id [英] column '_id' does not exist although ID have changed to _id
本文介绍了'_id'不存在，尽管ID列已更改为_id的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有我的 ID 重命名为 _id ，但仍获得列'_id'不存在 ...难道我错过了什么？
MyDatabaseelper.java
公共类MyDatabaseHelper扩展SQLiteOpenHelper {
公共静态最终诠释DATABASE_VERSION = 1;
公共静态最后弦乐DATABASE_NAME =alm.db;
公共静态最后弦乐TABLE_INFO =信息;
公共静态最后弦乐TABLE_WORKFORCE =劳动力;
公共静态最后弦乐TABLE_WORKDETAILS =WorkDetails;
公共静态最后弦乐分包商=分包商;
公共静态最后弦乐NumberOfPerson =NumberOfPerson;
公共静态最后弦乐NUMBEROFHOURS =NUMBEROFHOURS;
公共静态最后弦乐ID =_ ID;
公共静态最后弦乐TimeIn_Info =timeIn_Info;
公共静态最后弦乐TimeOut_Info =timeOut_Info; 公共无效的onCreate（SQLiteDatabase DB）{
db.execSQL（CREATE TABLE+ TABLE_INFO +（ID INTEGER PRIMARY KEY，Name文本，天气文本，日期DATETIME，状态文本，TimeIn_Info约会时，TimeOut_Info DATETIME））;
db.execSQL（CREATE TABLE+ TABLE_WORKFORCE +（ID INTEGER PRIMARY KEY，分包商TEXT，NumberOfPerson INTEGER，NUMBEROFHOURS TEXT，INTEGER TInfo_id，外键（TInfo_id）参考+ TABLE_INFO +（ID）））;}
ListDisplay.java
公共类ListDisplay扩展AppCompatActivity {
InfoAPI sqlcon;
私人SimpleCursorAdapter DataAdapter的;
公共无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.listdisplay1）;
sqlcon =新InfoAPI（本）;
最后弦乐名1 = getIntent（）getExtras（）的getString（名称）。;
BuildList（名称1）;
} 公共无效BuildList（字符串名称）{
最后弦乐名1 =名称;
sqlcon.open（）;
光标光标= sqlcon.readEntry（名称1）; 的String [] =列新的String [] {
MyDatabaseHelper.Weather,MyDatabaseHelper.Date,MyDatabaseHelper.Status,MyDatabaseHelper.TimeIn,MyDatabaseHelper.TimeOut
}; INT []为= INT新[] {
R.id.weather，R.id.date，R.id.status，R.id.in，R.id.out
}; //创建使用光标指向所希望的数据的转接器
//以及布局信息
DataAdapter的=新SimpleCursorAdapter（
对此，R.layout.listdispaly，
光标，
列，
至，
0）; ListView控件的ListView =（ListView控件）findViewById（R.id.listView1）;
//指定适配器的ListView
listView.setAdapter（DataAdapter的）;
}}
InfoAPI.java
公共光标readEntry（字符串名称）
{
光标C = database.rawQuery（SELECT天气，日期，状态，TimeIn_Info，TimeOut_Info FROM+ MyDatabaseHelper.TABLE_INFO +其中name =？，新的String [] {将String.valueOf（名）}，NULL）; 如果（C！= NULL）{
c.moveToFirst（）;
}
返回℃;
}
}
LogCat中错误
产生的原因：java.lang.IllegalArgumentException异常：列'_id'不存在
在android.database.AbstractCursor.getColumnIndexOrThrow（AbstractCursor.java:333）
在android.widget.CursorAdapter.init（CursorAdapter.java:180）
在android.widget.CursorAdapter＆LT;＆初始化GT;（CursorAdapter.java:157）
在android.widget.ResourceCursorAdapter＆LT;＆初始化GT;（ResourceCursorAdapter.java:96）
在android.widget.SimpleCursorAdapter＆LT;＆初始化GT;（SimpleCursorAdapter.java:104）
在com.example.project.project.ListDisplay.BuildList（ListDisplay.java:49）
在com.example.project.project.ListDisplay.onCreate（ListDisplay.java:31）
在android.app.Activity.performCreate（Activity.java:6237）
在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1107）
在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2369）
在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2476）
在android.app.ActivityThread.-wrap11（ActivityThread.java）
在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1344）
解决方案
在创建表的查询仍在使用ID（硬codeD字符串）
公共无效的onCreate（SQLiteDatabase DB）{
db.execSQL（CREATE TABLE+ TABLE_INFO +（+ ID +INTEGER PRIMARY KEY，Name文本，天气文本，日期DATETIME，状态文本，TimeIn_Info约会时，TimeOut_Info DATETIME））;
db.execSQL（CREATE TABLE+ TABLE_WORKFORCE +（+ ID +INTEGER PRIMARY KEY，分包商TEXT，NumberOfPerson INTEGER，NUMBEROFHOURS TEXT，INTEGER TInfo_id，外键（TInfo_id）参考+ TABLE_INFO +（ID））） ;
}
你将不得不迫使你要么分贝完全地卸载从您的设备的应用程序，然后重新安装或递增版本的升级。
的 SimpleCursorAdapter 希望 _id 中的光标。它添加到查询，例如
光标C = database.rawQuery（选择_id，天气，日期，状态，TimeIn_Info，TimeOut_Info FROM+ MyDatabaseHelper.TABLE_INFO +其中name =？，新的String [] {将String.valueOf（名）}，NULL）;
I have rename my ID to _id, but still get column '_id' does not exist ...Have I missed anything?
MyDatabaseelper.java
public class MyDatabaseHelper extends SQLiteOpenHelper {
public static final int DATABASE_VERSION=1;
public static final String DATABASE_NAME="alm.db";
public static final String TABLE_INFO="Information";
public static final String TABLE_WORKFORCE="WorkForce";
public static final String TABLE_WORKDETAILS="WorkDetails";
public static final String Subcontractors="Subcontractors";
public static final String NumberOfPerson="NumberOfPerson";
public static final String NumberOfHours="NumberOfHours";
public static final String ID="_id";
public static final String TimeIn_Info="timeIn_Info";
public static final String TimeOut_Info="timeOut_Info";
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_INFO + "(ID INTEGER PRIMARY KEY ,Name TEXT,Weather TEXT, Date DATETIME, Status Text, TimeIn_Info DATE TIME, TimeOut_Info DATETIME)");
db.execSQL("create table " + TABLE_WORKFORCE + "(ID INTEGER PRIMARY KEY ,Subcontractors TEXT,NumberOfPerson INTEGER,NumberOfHours TEXT, TInfo_id INTEGER, FOREIGN KEY(TInfo_id) REFERENCES "+TABLE_INFO+"(ID))");
}
ListDisplay.java
public class ListDisplay extends AppCompatActivity {
InfoAPI sqlcon;
private SimpleCursorAdapter dataAdapter;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listdisplay1);
sqlcon = new InfoAPI(this);
final String name1 = getIntent().getExtras().getString("name");
BuildList(name1);
}
public void BuildList(String name) {
final String name1 = name;
sqlcon.open();
Cursor cursor=sqlcon.readEntry(name1);
String[] columns=new String[]{
MyDatabaseHelper.Weather,MyDatabaseHelper.Date,MyDatabaseHelper.Status,MyDatabaseHelper.TimeIn,MyDatabaseHelper.TimeOut
};
int[] to=new int[]{
R.id.weather,R.id.date,R.id.status,R.id.in,R.id.out
};
// create the adapter using the cursor pointing to the desired data
//as well as the layout information
dataAdapter = new SimpleCursorAdapter(
this, R.layout.listdispaly,
cursor,
columns,
to,
0);
ListView listView = (ListView) findViewById(R.id.listView1);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
}
}
InfoAPI.java
public Cursor readEntry(String name)
{
Cursor c=database.rawQuery("SELECT Weather, Date, Status, TimeIn_Info, TimeOut_Info FROM " + MyDatabaseHelper.TABLE_INFO + " WHERE Name = ?", new String[]{String.valueOf(name)}, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
}
LogCat Error
Caused by: java.lang.IllegalArgumentException: column '_id' does not exist
at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:333)
at android.widget.CursorAdapter.init(CursorAdapter.java:180)
at android.widget.CursorAdapter.<init>(CursorAdapter.java:157)
at android.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:96)
at android.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:104)
at com.example.project.project.ListDisplay.BuildList(ListDisplay.java:49)
at com.example.project.project.ListDisplay.onCreate(ListDisplay.java:31)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
解决方案
you create table queries are still using "ID" (hard-coded string)
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_INFO + " ( " + ID + " INTEGER PRIMARY KEY ,Name TEXT,Weather TEXT, Date DATETIME, Status Text, TimeIn_Info DATE TIME, TimeOut_Info DATETIME)");
db.execSQL("create table " + TABLE_WORKFORCE + " ( " + ID + " INTEGER PRIMARY KEY ,Subcontractors TEXT,NumberOfPerson INTEGER,NumberOfHours TEXT, TInfo_id INTEGER, FOREIGN KEY(TInfo_id) REFERENCES "+TABLE_INFO+"(ID))");
}
you will have to force an upgrade of your db either uninstalling completly the app from your device and reinstalling it again or incrementing VERSION.
The SimpleCursorAdapter wants the _id in the cursor. Add it to the query, E.g.
Cursor c=database.rawQuery("SELECT _id, Weather, Date, Status, TimeIn_Info, TimeOut_Info FROM " + MyDatabaseHelper.TABLE_INFO + " WHERE Name = ?", new String[]{String.valueOf(name)}, null);
这篇关于'_id'不存在，尽管ID列已更改为_id的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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