如何在现有数据库中添加新表 [英] how to add a new table in existing database
本文介绍了如何在现有数据库中添加新表的处理方法，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
我试图在数据库中添加一个新表，但是每当我运行我的应用程序时，它都会给我一个错误表名不存在，如何添加一个具有 samoe 字段和函数的表以从用户那里获取数据，即他写在活动的编辑文本中.
i m trying to add a new table in the database,but whenever i run my application,it give me an error tablename doesnot exist,how to add a table that have samoe fields and function to get the data from the user ,that he write in the activity's edittext.
package com.example.smscampaign;
import java.util.ArrayList;
import java.util.List;
import org.w3c.dom.Comment;
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.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelp {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "person_name";
public static final String KEY_SCALE = "scale_person";
public static final String KEY_CONTACTS = "Contacts_person";
public static final String KEY_To_ROWID = "_id";
public static final String KEY_To_NAME = "person_name";
public static final String KEY_To_SCALE = "scale_person";
public static final String KEY_To_CONTACTS = "Contacts_person";
private static final String DATABASE_NAME = "Himani";
static final String DATABASE_TABLE = "peopleTable";
private static final String TABLE_ADD_MESSAGE = "Add_Message";
private static final int DATABASE_VERSION = 1;
private DbHelper ourHepler;
private final Context ourContext;
SQLiteDatabase ourDatabase;
public class DbHelper extends SQLiteOpenHelper {
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL( "CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_SCALE + " TEXT NOT NULL ," + KEY_CONTACTS + ")"
);
String CREATE_ADD_MESSAGE= "CREATE TABLE " + TABLE_ADD_MESSAGE +
"(" + KEY_To_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_To_NAME + " TEXT NOT NULL, " +
KEY_To_SCALE + " TEXT NOT NULL ," + KEY_To_CONTACTS + ")" ;
db.execSQL(CREATE_ADD_MESSAGE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS" + DATABASE_TABLE);
db.execSQL("DROP TABLE IF EXISTS" + TABLE_ADD_MESSAGE);
onCreate(db);
}
}
public DatabaseHelp(Context c) {
ourContext = c;
}
public DatabaseHelp open() throws SQLException {
ourHepler = new DbHelper(ourContext);
ourDatabase = ourHepler.getWritableDatabase();
return this;
}
public void close() {
ourHepler.close();
}
public long entryCreate(String name, String scale, String contacts) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_SCALE, scale);
cv.put(KEY_CONTACTS, contacts);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}
public long entryCreate1(String name, String scale, String contacts) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_To_NAME, name);
cv.put(KEY_To_SCALE, scale);
cv.put(KEY_To_CONTACTS, contacts);
return ourDatabase.insert(TABLE_ADD_MESSAGE, null, cv);
}
public ArrayList<String> getData() {
String[] col = new String[] { KEY_ROWID, KEY_NAME, KEY_SCALE,
KEY_CONTACTS };
Cursor c = ourDatabase.query(DATABASE_TABLE, col, null, null, null,
null, null);
String run = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iScale = c.getColumnIndex(KEY_SCALE);
int iMessage = c.getColumnIndex(KEY_CONTACTS);
ArrayList<String> newList = new ArrayList<String>();
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
newList.add(c.getString(iName));
}
return newList;
}
public ArrayList<String> getData1() {
String[] col = new String[] { KEY_To_ROWID, KEY_To_NAME, KEY_To_SCALE,
KEY_To_CONTACTS };
Cursor c = ourDatabase.query(TABLE_ADD_MESSAGE, col, null, null, null,
null, null);
String run = "";
int iRow = c.getColumnIndex(KEY_To_ROWID);
int iName = c.getColumnIndex(KEY_To_NAME);
int iScale = c.getColumnIndex(KEY_To_SCALE);
int iMessage = c.getColumnIndex(KEY_To_CONTACTS);
ArrayList<String> newList = new ArrayList<String>();
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
newList.add(c.getString(iName));
}
return newList;
}
public Cursor fetchChildren(String KEY_) {
Cursor c = ourDatabase.rawQuery("SELECT * FROM " + DATABASE_TABLE
+ " WHERE person_name = ?", new String[] { KEY_ });
return c;
}
public Cursor fetchChildren1(String KEY_) {
Cursor c = ourDatabase.rawQuery("SELECT * FROM " + DATABASE_TABLE
+ " WHERE person_name = ?", new String[] { KEY_ });
return c;
}
public String getScale(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_ROWID, KEY_NAME, KEY_SCALE,
KEY_CONTACTS };
Cursor c = ourDatabase.query(DATABASE_TABLE, col, KEY_ROWID + "-" + l,
null, null, null, null);
if (c != null) {
c.moveToFirst();
String scale = c.getString(2);
return scale;
}
return null;
}
public String getScale1(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_To_ROWID, KEY_To_NAME, KEY_To_SCALE,
KEY_To_CONTACTS };
Cursor c = ourDatabase.query(TABLE_ADD_MESSAGE, col, KEY_To_ROWID + "-"
+ l, null, null, null, null);
if (c != null) {
c.moveToFirst();
String scale = c.getString(2);
return scale;
}
return null;
}
public String getName(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_ROWID, KEY_NAME, KEY_SCALE,
KEY_CONTACTS };
Cursor c = ourDatabase.query(DATABASE_TABLE, col, KEY_ROWID + "-" + l,
null, null, null, null);
if (c != null) {
c.moveToFirst();
String name = c.getString(1);
return name;
}
return null;
}
public String getName1(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_To_ROWID, KEY_To_NAME, KEY_SCALE,
KEY_To_CONTACTS };
Cursor c = ourDatabase.query(TABLE_ADD_MESSAGE, col, KEY_To_ROWID + "-"
+ l, null, null, null, null);
if (c != null) {
c.moveToFirst();
String name = c.getString(1);
return name;
}
return null;
}
public String getContacts(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_ROWID, KEY_NAME, KEY_SCALE,
KEY_CONTACTS };
Cursor c = ourDatabase.query(DATABASE_TABLE, col, KEY_ROWID + "-" + l,
null, null, null, null);
if (c != null) {
c.moveToFirst();
String contacts = c.getString(3);
return contacts;
}
return null;
}
public String getContacts1(long l) {
// TODO Auto-generated method stub
String[] col = new String[] { KEY_To_ROWID, KEY_To_NAME, KEY_To_SCALE,
KEY_To_CONTACTS };
Cursor c = ourDatabase.query(TABLE_ADD_MESSAGE, col, KEY_To_ROWID + "-"
+ l, null, null, null, null);
if (c != null) {
c.moveToFirst();
String contacts = c.getString(3);
return contacts;
}
return null;
}
public void updateEntry(long lt, String mName, String mScale,
String mContatcs) {
// TODO Auto-generated method stub
ContentValues cvUpdate = new ContentValues();
cvUpdate.put(KEY_NAME, mName);
cvUpdate.put(KEY_SCALE, mScale);
cvUpdate.put(KEY_CONTACTS, mContatcs);
ourDatabase
.update(DATABASE_TABLE, cvUpdate, KEY_ROWID + "-" + lt, null);
}
public void updateEntry1(long lt, String mName, String mScale,
String mContatcs) {
// TODO Auto-generated method stub
ContentValues cvUpdate = new ContentValues();
cvUpdate.put(KEY_To_NAME, mName);
cvUpdate.put(KEY_To_SCALE, mScale);
cvUpdate.put(KEY_To_CONTACTS, mContatcs);
ourDatabase.update(TABLE_ADD_MESSAGE, cvUpdate,
KEY_To_ROWID + "-" + lt, null);
}
public void deleteEntry1(long ltt) throws SQLException {
// TODO Auto-generated method stub
ourDatabase.delete(TABLE_ADD_MESSAGE, KEY_To_ROWID + "=" + ltt, null);
}
public void deleteEntry(long ltt) throws SQLException {
// TODO Auto-generated method stub
ourDatabase.delete(DATABASE_TABLE, KEY_ROWID + "=" + ltt, null);
}
}
总是出现这个错误
> 03-19 16:46:52.396: E/AndroidRuntime(10089):
> java.lang.RuntimeException: Unable to start activity
> ComponentInfo{com.example.smscampaign/com.example.smscampaign.Campaign_Details}:
> android.database.sqlite.SQLiteException: no such table: Add_Message
> (code 1): , while compiling: SELECT _id, name, message, Contacts FROM
> Add_Message
推荐答案
Increment DATABASE_VERSION 所以你的 onUpgrade() 被调用.
Increment DATABASE_VERSION so your onUpgrade() is called.
有关更多信息，请参阅SQLiteOpenHelper onCreate()/onUpgrade() 何时运行?
这篇关于如何在现有数据库中添加新表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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