在code错误查看sqlLite数据库 [英] error in code to view sqlLite Database

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问题描述

我想用光标来查看一个TextView数据库的内容,但是当我尝试运行应用程序崩溃......我不能确定它的误差

 包aditya.testapp;

进口android.content.ContentValues​​;
进口android.content.Context;
进口android.database.Cursor;
进口android.database.SQLException;
进口android.database.sqlite.SQLiteDatabase;
进口android.database.sqlite.SQLiteOpenHelper;

公共类SQLDATA {

公共静态最后弦乐KEY_ROWID =_id;
公共静态最后弦乐KEY_NAME =persons_name;
公共静态最后弦乐KEY_NUMBER =persons_number;

私有静态最后弦乐DATABASE_NAME =DataDb;
私有静态最后弦乐DATABASE_TABLE =peopleTable;
私有静态最终诠释DATABASE_VERSION = 2;

私人DbHelper ourHelper;
私人最终语境ourContext;
私人SQLiteDatabase ourDatabase;

//XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

私有静态类DbHelper扩展SQLiteOpenHelper {

    公共DbHelper(上下文的背景下){
        超(背景下,DATABASE_NAME,空,DATABASE_VERSION);
        // TODO自动生成构造函数存根
    }


    // onCreate方法仅在创建数据库时,使用一次....其他时间onUpgrade梅索德使用
    @覆盖
    公共无效的onCreate(SQLiteDatabase DB){
        // TODO自动生成方法存根
        db.execSQL(CREATE TABLE+ DATABASE_TABLE +(+
        KEY_ROWID +INTEGER PRIMARY KEY,+
        KEY_NAME +TEXT NOT NULL,+
        KEY_NUMBER +TEXT NOT NULL);
                );
    }

    @覆盖
    公共无效onUpgrade(SQLiteDatabase分贝,INT oldVersion,诠释静态网页){
        // TODO自动生成方法存根
        db.execSQL(DROP TABLE IF EXISTS+ DATABASE_TABLE);
        的onCreate(DB);
    }}

//初始化背景下ourContext
公共SQLDATA(上下文C){
    ourContext = C;
    }
// XX
公共SQLDATA的open()抛出的SQLException {
    ourHelper =新DbHelper(ourContext);
    ourDatabase = ourHelper.getWritableDatabase();
    回到这一点;
}
公共无效的close(){
    ourHelper.close();
}

众长createEntry(字符串名称,串号){
    // TODO自动生成方法存根
    //表ContentValues​​用来束代替
    ContentValues​​ CV =新ContentValues​​();
    cv.put(KEY_NAME,姓名);
    cv.put(KEY_NUMBER,数量);
    返回ourDatabase.insert(DATABASE_TABLE,空,CV);
}

公共字符串的getData(){

    // TODO自动生成方法存根
    的String []列=新的String [] {KEY_ROWID,KEY_NAME,KEY_NUMBER};
    光标C = ourDatabase.query(DATABASE_TABLE,列,NULL,NULL,NULL,NULL,NULL);
    字符串结果=;

    INT iRow = c.getColumnIndex(KEY_ROWID);
    INT INAME = c.getColumnIndex(KEY_NAME);
    INT i编号= c.getColumnIndex(KEY_NUMBER);

    为(c.moveToFirst();!c.isAfterLast(); c.moveToNext()){
        结果=结果+ c.getString(iRow)++ c.getString(INAME)++ c.getString(i编号)+/ N的;
    }
    c.close();
    返回结果;


}
}
 

和此code是对于被用于查看数据库中的类

 进口android.app.Activity;
进口android.os.Bundle;
进口android.widget.TextView;

公共类SqlView延伸活动{
@覆盖
保护无效的onCreate(包savedInstanceState){
    // TODO自动生成方法存根
    super.onCreate(savedInstanceState);
    的setContentView(R.layout.sqlview);
    TextView的lblSqlInfo =(TextView中)findViewById(R.id.lblSqlInfo);
    SQLDATA信息=新SQLDATA(本);
    info.open();
    字符串数据= info.getData(); //的getData是SQLDATA类中的方法
    info.close();
    lblSqlInfo.setText(数据);
}
 

}

请帮忙找出错误....日志猫显示此错误

  12月10日至22日:51:56.483:E / AndroidRuntime(1815):致命异常:主要
12月10号至22日:51:56.483:E / AndroidRuntime(1815):java.lang.RuntimeException的:无法启动的活动ComponentInfo {aditya.testapp / aditya.testapp.SqlView}:android.database.sqlite.SQLiteException:没有这样的列:_id(code 1):在编制:选择_id,persons_name,persons_number从peopleTable
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.ActivityThread.access $ 600(ActivityThread.java:141)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.ActivityThread $ H.handleMessage(ActivityThread.java:1234)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.os.Handler.dispatchMessage(Handler.java:99)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.os.Looper.loop(Looper.java:137)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.ActivityThread.main(ActivityThread.java:5041)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在java.lang.reflect.Method.invokeNative(本机方法)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在java.lang.reflect.Method.invoke(Method.java:511)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:793)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在dalvik.system.NativeStart.main(本机方法)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):android.database.sqlite.SQLiteException:没有这样的列:_id(code1):由引起的,而编译:选择_id,persons_name,persons_number从peopleTable
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteConnection.native prepareStatement(本机方法)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteConnection.acquire preparedStatement(SQLiteConnection.java:882)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteConnection prepare(SQLiteConnection.java:493)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteSession prepare(SQLiteSession.java:588)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteProgram< INIT>(SQLiteProgram.java:58)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteQuery< INIT>(SQLiteQuery.java:37)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在aditya.testapp.SqlData.getData(SqlData.java:79)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在aditya.testapp.SqlView.onCreate(SqlView.java:16)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.Activity.performCreate(Activity.java:5104)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
12月10号至22日:51:56.483:E / AndroidRuntime(1815):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
    12月10号至22日:51:56.483:E / AndroidRuntime(1815):11 ...更多
 

解决方案

  android.database.sqlite.SQLiteException:没有这样的列:_id(code 1):在编制:选择_id,persons_name,persons_number从peopleTable
 

您的表没有一个名为 _id 列。添加它,并重新创建数据库。或者从您的选择列中删除。

好像有在的onCreate SQL语法问题()

  db.execSQL(CREATE TABLE+ DATABASE_TABLE +(+
KEY_ROWID +INTEGER PRIMARY KEY,+
KEY_NAME +TEXT NOT NULL,+
KEY_NUMBER +TEXT NOT NULL);
 

应该有列名和类型,如:

之间的空间

  db.execSQL(CREATE TABLE+ DATABASE_TABLE +(+
KEY_ROWID +INTEGER PRIMARY KEY,+
KEY_NAME +TEXT NOT NULL,+
KEY_NUMBER +TEXT NOT NULL);
 

这是因为例如一个棘手的问题 _idINTEGER PRIMARY KEY 是一个有效的列规范,它只是不指定指定的列 _id

在改变这样的模式,记得撞了数据库的版本号。

I am trying to view the contents of a database in a TextView by using Cursor but when i try running the app crashes...I cannot identify it the error

package aditya.testapp;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class SqlData {

public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "persons_name";
public static final String KEY_NUMBER = "persons_number";

private static final String DATABASE_NAME = "DataDb";
private static final String DATABASE_TABLE = "peopleTable";
private static final int DATABASE_VERSION =  2 ;

private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;

//XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

private static class DbHelper extends SQLiteOpenHelper{

    public DbHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        // TODO Auto-generated constructor stub
    }


    // onCreate method only used once when a database is created....other times onUpgrade methode is used
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
        KEY_ROWID + "INTEGER PRIMARY KEY, " +
        KEY_NAME + "TEXT NOT NULL, " +
        KEY_NUMBER + "TEXT NOT NULL);"
                );
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
        onCreate(db);
    }}

// initializing context ourContext
public SqlData (Context c){
    ourContext = c;
    }
//XX
public SqlData open() throws SQLException{
    ourHelper = new DbHelper(ourContext);
    ourDatabase = ourHelper.getWritableDatabase();
    return this;
}
public void close(){
    ourHelper.close(); 
}

public long createEntry(String name, String number) {
    // TODO Auto-generated method stub
    // in table ContentValues is used instead of bundle
    ContentValues cv = new ContentValues();
    cv.put(KEY_NAME, name);
    cv.put(KEY_NUMBER, number);
    return ourDatabase.insert(DATABASE_TABLE, null, cv);
}

public String getData() {

    // TODO Auto-generated method stub
    String[] columns = new String[]{KEY_ROWID , KEY_NAME , KEY_NUMBER};
    Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
    String result = "";

    int iRow = c.getColumnIndex(KEY_ROWID);
    int iName = c.getColumnIndex(KEY_NAME);
    int iNumber = c.getColumnIndex(KEY_NUMBER);

    for( c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
        result = result + c.getString(iRow) + "   " + c.getString(iName) + "    " + c.getString(iNumber) + "/n";
    } 
    c.close();
    return result;


}
}

and this code is for the class which is used to view the database

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class SqlView extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.sqlview);
    TextView lblSqlInfo = (TextView) findViewById(R.id.lblSqlInfo);
    SqlData info = new SqlData(this);
    info.open();
    String data = info.getData();    // getData is a method in SqlData class
    info.close();
    lblSqlInfo.setText(data);
}

}

Please help to find out the error.... The log cat shows this error

10-22 12:51:56.483: E/AndroidRuntime(1815): FATAL EXCEPTION: main
10-22 12:51:56.483: E/AndroidRuntime(1815): java.lang.RuntimeException: Unable to start activity ComponentInfo{aditya.testapp/aditya.testapp.SqlView}: android.database.sqlite.SQLiteException: no such column: _id (code 1): , while compiling: SELECT _id, persons_name, persons_number FROM peopleTable
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.os.Looper.loop(Looper.java:137)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.ActivityThread.main(ActivityThread.java:5041)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at java.lang.reflect.Method.invokeNative(Native Method)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at java.lang.reflect.Method.invoke(Method.java:511)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at dalvik.system.NativeStart.main(Native Method)
10-22 12:51:56.483: E/AndroidRuntime(1815): Caused by: android.database.sqlite.SQLiteException: no such column: _id (code 1): , while compiling: SELECT _id, persons_name, persons_number FROM peopleTable
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at aditya.testapp.SqlData.getData(SqlData.java:79)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at aditya.testapp.SqlView.onCreate(SqlView.java:16)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.Activity.performCreate(Activity.java:5104)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
10-22 12:51:56.483: E/AndroidRuntime(1815):     at   android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
    10-22 12:51:56.483: E/AndroidRuntime(1815):     ... 11 more

解决方案

android.database.sqlite.SQLiteException: no such column: _id (code 1): , while compiling: SELECT _id, persons_name, persons_number FROM peopleTable

Your table doesn't have a column called _id. Add it there and recreate the database. Or remove it from your selection columns.

Seems like there are SQL syntax problems in onCreate():

db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + "INTEGER PRIMARY KEY, " +
KEY_NAME + "TEXT NOT NULL, " +
KEY_NUMBER + "TEXT NOT NULL);"

There should be space between column name and type, e.g.

db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_NUMBER + " TEXT NOT NULL);"

This is a tricky issue since e.g. _idINTEGER PRIMARY KEY is a valid column specification, it just doesn't specify a column named _id.

When changing the schema like this, remember to bump up the database version number.

这篇关于在code错误查看sqlLite数据库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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