嗨，我刚刚进入android编程我想在android应用程序中使用sqlite数据库来处理一些与数据库相关的东西。我正在开发应用程序，就像它将从家里扫描一些wifi设备到那里供应商ID应该在列表视图中显示按下列表中的任何项目它应该发送一些udp按摩到该受尊重的设备得到响应udp按摩它应该再创建一个listview为那个回应。我已经实现了Udp相关的东西和扫描wifi设备相关的东西，但只有这是剩下的是获取设备我需要存储该设备进一步udp相关的东西和维护数据库可以任何人有最好的建议。
lass IP_Channal_DB extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "note.db";
private static final String Table_NAME = "Ip_channal_Table";
private static final String Col_1 = "ID";
private static final String Col_2 = "IP_Address";
private static final String Col_3 = "Flag";
private static final String Col_4 = "Channal_1";
private static final String Col_5 = "Channal_2";
private static final String Col_6 = "Channal_3";
private static final String Col_7 = "Channal_4";
private static final int SCHEMA_VERSION = 1;
private static final String DATABASE_CREATE = "CREATE TABLE " + Table_NAME + " (" + Col_1 + " integer PRIMARY KEY autoincrement," + Col_2 + "TEXT," + Col_3 + "TEXT," + Col_4 + "TEXT," + Col_5 + "TEXT," + Col_6 + "TEXT," + Col_7 + "TEXT,)";
public IP_Channal_DB(Context context) {
super(context, DATABASE_NAME, null, SCHEMA_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.v("MainActivity","creating table");
db.execSQL(DATABASE_CREATE);
//db.execSQL("CREATE TABLE "+Table_NAME+"("+Col_1+" INTEGER PRIMARY KEY AUTOINCREMENT,"+Col_2+" TEXT,"+Col_3+"INTEGER,"+Col_4+" TEXT,"+Col_5+" TEXT,"+Col_6+" TEXT,"+Col_7+" TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
/* public Cursor getAll_IP()
{
return (getReadableDatabase().rawQuery("SELECT "+Col_1+", "+Col_2+" FROM "+Table_NAME,null));
}*/
public Cursor getAll_IP()
{
SQLiteDatabase db=this.getReadableDatabase();
Cursor cur=db.rawQuery("SELECT "+Col_1+" as _id, "+Col_2+" from "+Table_NAME,new String [] {});
return cur;
}
}
和logcat窗口是
03-31 14:39:36.547 1681-1681/com.example.admin.myhome E/SQLiteLog: (1) no such table: Ip_channal_Table
03-31 14:39:36.557 1681-1681/com.example.admin.myhome E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.admin.myhome, PID: 1681
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.admin.myhome/com.example.admin.myhome.MainActivity}: android.database.sqlite.SQLiteException: no such table: Ip_channal_Table (code 1): , while compiling: SELECT ID as _id, IP_Address from Ip_channal_Table
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2348)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2410)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4019)
at android.app.ActivityThread.access$900(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1319)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5345)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:947)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:742)
Caused by: android.database.sqlite.SQLiteException: no such table: Ip_channal_Table (code 1): , while compiling: SELECT ID as _id, IP_Address from Ip_channal_Table
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1316)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1255)
at com.example.admin.myhome.IP_Channal_DB.getAll_IP(NoteHolder.java:52)
at com.example.admin.myhome.MainActivity$override.onCreate(MainActivity.java:131)
at com.example.admin.myhome.MainActivity$override.access$dispatch(MainActivity.java)
at com.example.admin.myhome.MainActivity.onCreate(MainActivity.java:0)
at android.app.Activity.performCreate(Activity.java:6012)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2292)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2410)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4019)
at android.app.ActivityThread.access$900(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1319)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5345)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:947)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:742)
答案 0 :(得分：1)
我开发了一个我在主应用程序中使用的示例项目。我希望这对你也有帮助。
<强> DataBaseHandler.java
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
public class DataBaseHandler extends SQLiteOpenHelper {
public String BooksTable="Books";
public String Book_Id="id";
public String BookAuther="BookAuther";
public String BookTitle="BookTitle";
private final int DB_Version=1;
public DataBaseHandler(Context context,String DBName,int DBVersion){
super(context, DBName,null,DBVersion);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("Create Table " + BooksTable + "(" + Book_Id + " INTEGER PRIMARY KEY, " + BookAuther + " Text, " + BookTitle + " Text);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public void addBook(Book book){
SQLiteDatabase db=this.getWritableDatabase();
ContentValues cv=new ContentValues();
cv.put(Book_Id,book.getId());
cv.put(BookAuther,book.getAuthor());
cv.put(BookTitle,book.getTitle());
db.insert(BooksTable, null, cv);
db.close();
}
public ArrayList<Book> fetchAllBooks(){
ArrayList<Book> booksList = new ArrayList<Book>();
SQLiteDatabase db=this.getReadableDatabase();
Cursor c= db.query(BooksTable, null, null, null, null, null, null);
c.moveToFirst();
while (!c.isAfterLast()){
Book book = new Book();
book.setId(c.getInt(0));
book.setAuthor(c.getString(1));
book.setTitle(c.getString(2));
booksList.add(book);
c.moveToNext();
}
db.close();
return booksList;
}
}
<强> Book.java
public class Book {
private int id;
private String author;
private String title;
public void setId(int id) {
this.id = id;
}
public void setAuthor(String author) {
this.author = author;
}
public void setTitle(String title) {
this.title = title;
}
public int getId() {
return id;
}
public String getAuthor() {
return author;
}
public String getTitle() {
return title;
}
}
<强> MainActivity.java
DataBaseHandler db=new DataBaseHandler(getApplicationContext(),"DB_Name",1);
Book book=new Book();
book.setId(1);
book.setTitle("My Title");
book.setAuthor("Name of Author");
db.addBook(book);