Android 升级我的SQLite数据库
我是SQLite的新手。Android 升级我的SQLite数据库,android,sqlite,android-sqlite,Android,Sqlite,Android Sqlite,我是SQLite的新手。 如何升级数据库 我以前的数据库版本中有7个问题。 今天我添加了大约13个新的,总共20个。 我使用addQuestion方法添加了它们。 但是,它不起作用 我一直在修补我的onUpgrade。 我做错了什么事 public class QuizHelper extends SQLiteOpenHelper { private static final int DATABASE_VERSION = 1; private static final Stri
如何升级数据库 我以前的数据库版本中有7个问题。
今天我添加了大约13个新的,总共20个。
我使用addQuestion方法添加了它们。
但是,它不起作用 我一直在修补我的onUpgrade。
我做错了什么事
public class QuizHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "creativequestion";
private static final String TABLE_QUEST = "quest";
private static final String KEY_ID = "qid";
private static final String KEY_QUEST = "question";
private SQLiteDatabase dbase;
public QuizHelper(Context context) {
super( context, DATABASE_NAME, null, DATABASE_VERSION );
}
@Override
public void onCreate(SQLiteDatabase db) {
dbase = db;
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST + " ( " + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUEST + " TEXT)";
db.execSQL( sql );
addQuestion();
}
private void addQuestion() {
QuestionFaci q1 = new QuestionFaci( "OTHER USES: Name other uses of a Hammer. \n\n Example: Stir a soup." );
this.addQuestion(q1);
QuestionFaci q2 = new QuestionFaci( "RHYMES: Words that rhymes with Rice. \n\n Example: Ice" );
this.addQuestion(q2);
QuestionFaci q3 = new QuestionFaci( "WITH: I can cook eggs with... \n\n Example: A Piece of Plywood" );
this.addQuestion(q3);
QuestionFaci q4 = new QuestionFaci( "WITHOUT: I can wash my clothes without... \n\n Example: My Aunt" );
this.addQuestion(q4);
QuestionFaci q5 = new QuestionFaci( "I WILL: If I was Bill Gates, I will... \n\n Example: Buy a spaceship" );
this.addQuestion(q5);
QuestionFaci q6 = new QuestionFaci( "CREATE A MOVIE TITLE: A NIGHT \n\n Example: To Remember" );
this.addQuestion(q6);
QuestionFaci q7 = new QuestionFaci( "OTHER NAMES: Other names of a cow \n\n Example: Milk giver" );
this.addQuestion(q7);
QuestionFaci q8 = new QuestionFaci( "OTHER USES: Name other uses of a Cowboy Boots. \n\n Example: Pound a nail." );
this.addQuestion(q8);
QuestionFaci q9 = new QuestionFaci( "RHYMES: Bake a. \n\n Example: Flake." );
this.addQuestion(q9);
QuestionFaci q10 = new QuestionFaci( "I WILL: I will drive a helicopter \n\n Example: with eyes closed" );
this.addQuestion(q10);
QuestionFaci q11 = new QuestionFaci( "CREATE A TITLE: The Greatest \n\n Example: Heist" );
this.addQuestion(q11);
QuestionFaci q12 = new QuestionFaci( "CHANGE AN INGREDIENT: --- Cookie \n\n Example: Orange Chip" );
this.addQuestion(q12);
QuestionFaci q13 = new QuestionFaci( "FINISH ME: Can you remember the times when.. \n\n Example: push me over a cliff" );
this.addQuestion(q13);
QuestionFaci q14 = new QuestionFaci( "OTHER NAMES: Ball bearings \n\n Example: Mommy's new bangles" );
this.addQuestion(q14);
QuestionFaci q15 = new QuestionFaci( "FINISH ME: The donut rolls \n\n Example: down the hill" );
this.addQuestion(q15);
QuestionFaci q16 = new QuestionFaci( "RHYMES: Flip the \n\n Example: clip" );
this.addQuestion(q16);
QuestionFaci q17 = new QuestionFaci( "OTHER NAMES: Police \n\n Example: civilian peacekeeper" );
this.addQuestion(q17);
QuestionFaci q18 = new QuestionFaci( "CREATE A TITLE: Go Go \n\n Example: Changin" );
this.addQuestion(q18);
QuestionFaci q19 = new QuestionFaci( "I WILL: I will distribute screwdrivers \n\n Example: to all drivers" );
this.addQuestion(q19);
QuestionFaci q20 = new QuestionFaci( "CREATE A DISH: Chicken --- Soup \n\n Example: Dumpling" );
this.addQuestion(q20);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
String upgradeQuery = "ALTER TABLE quest ADD COLUMN question TEXT";
if(newV>oldV)
db.execSQL( upgradeQuery );
onCreate( db );
}
private void addQuestion(QuestionFaci quest) {
ContentValues values = new ContentValues( );
values.put(KEY_QUEST, quest.getQUESTION());
dbase.insert( TABLE_QUEST, null, values );
}
public List<QuestionFaci> getAllQuestions(){
List<QuestionFaci> quesList = new ArrayList<QuestionFaci>( );
String selectQuery = "SELECT * FROM " + TABLE_QUEST;
dbase = this.getReadableDatabase();
Cursor cursor = dbase.rawQuery( selectQuery, null );
if (cursor.moveToFirst()){
do{
QuestionFaci quest = new QuestionFaci( );
quest.setID( cursor.getInt( 0 ) );
quest.setQUESTION( cursor.getString( 1 ) );
quesList.add(quest);
} while (cursor.moveToNext());
}
return quesList;
}
}
public类QuizHelper扩展了SQLiteOpenHelper{
私有静态最终int数据库_VERSION=1;
私有静态最终字符串数据库\u NAME=“creativequestion”;
私有静态最终字符串表_QUEST=“QUEST”;
私有静态最终字符串密钥\u ID=“qid”;
私有静态最终字符串密钥\u QUEST=“question”;
专用数据库数据库;
公共QuizHelper(上下文){
super(上下文、数据库名称、null、数据库版本);
}
@凌驾
public void onCreate(SQLiteDatabase db){
dbase=db;
String sql=“如果不存在创建表”+表任务+”(“+KEY\u ID+”整型主键自动递增“+KEY\u任务+”文本)”;
execSQL(sql);
添加问题();
}
私人问题{
QuestionFaci q1=new QuestionFaci(“其他用途:命名锤子的其他用途。\n\n示例:搅拌汤”);
这个问题(q1);
QuestionFaci q2=新的QuestionFaci(“押韵:与Rice押韵的单词。\n\n示例:Ice”);
这个问题(q2);
QuestionFaci q3=新的QuestionFaci(“使用:我可以使用…\n\n示例:一块胶合板来煮鸡蛋”);
这个问题(第三季度);
QuestionFaci q4=新的QuestionFaci(“没有:我可以不洗衣服…\n\n示例:我的阿姨”);
这个问题(第四季度);
QuestionFaci q5=新的QuestionFaci(“我会:如果我是比尔·盖茨,我会…\n\n示例:买一艘宇宙飞船”);
这个问题(q5);
QuestionFaci q6=新建QuestionFaci(“创建电影标题:夜晚\n\n示例:记住”);
这个问题(q6);
QuestionFaci q7=新的QuestionFaci(“其他名称:奶牛的其他名称\n\n示例:送奶人”);
这个问题(q7);
QuestionFaci q8=新的QuestionFaci(“其他用途:命名牛仔靴的其他用途。\n\n示例:敲打钉子”);
这个问题(q8);
QuestionFaci q9=新的QuestionFaci(“押韵:烘焙a.\n\n示例:薄片”);
这个问题(q9);
QuestionFaci q10=新的QuestionFaci(“我将:我将驾驶直升机\n\n示例:闭上眼睛”);
本.补充质询(q10);
QuestionFaci q11=新的QuestionFaci(“创建一个标题:最伟大的\n\n示例:抢劫”);
本问题(q11);
QuestionFaci q12=新的QuestionFaci(“更改成分:---饼干\n\n示例:橙色芯片”);
本条问题(q12);
QuestionFaci q13=新的QuestionFaci(“完成我:你还记得….\n\n示例:将我推下悬崖的时间吗”);
本问题(第13题);
QuestionFaci q14=新的QuestionFaci(“其他名称:滚珠轴承\n\n示例:妈妈的新手镯”);
本.补充质询(问题14);
QuestionFaci q15=新的QuestionFaci(“完成我:甜甜圈滚动\n\n示例:下山”);
本.补充质询(第15题);
QuestionFaci q16=新的QuestionFaci(“押韵:翻转\n\n示例:剪辑”);
本.补充质询(第16题);
QuestionFaci q17=新的QuestionFaci(“其他名称:警察\n\n示例:文职维和人员”);
本.补充质询(第17题);
QuestionFaci q18=新建QuestionFaci(“创建标题:Go-Go\n\n示例:Changin”);
本.补充质询(第18题);
QuestionFaci q19=新的QuestionFaci(“我将:我将分发螺丝刀\n\n示例:所有螺丝刀”);
本.补充质询(第19题);
QuestionFaci q20=新的QuestionFaci(“创建一道菜:鸡肉---汤\n\n示例:饺子”);
这个问题(q20);
}
@凌驾
public void onUpgrade(SQLiteDatabase db、intoldv、intnewv){
String upgradeQuery=“ALTER TABLE quest ADD COLUMN quest TEXT”;
如果(新值>旧值)
execSQL(升级查询);
onCreate(db);
}
私人问题(提问){
ContentValues=新的ContentValues();
value.put(KEY_QUEST,QUEST.getQUESTION());
insert(TABLE_QUEST,null,value);
}
公共列表getAllQuestions(){
List quesList=newarraylist();
String selectQuery=“SELECT*FROM”+表格任务;
dbase=this.getReadableDatabase();
Cursor Cursor=dbase.rawQuery(selectQuery,null);
if(cursor.moveToFirst()){
做{
QuestionFaci quest=新的QuestionFaci();
setID(cursor.getInt(0));
setquest.setQUESTION(cursor.getString(1));
添加(任务);
}while(cursor.moveToNext());
}
返回任务列表;
}
}
您应该将数据库版本
变量增加到例如2。这将调用onUpgrade
方法
这不是最好的方法,但如果当前数据库的版本更高,您可以直接删除表,然后调用onCreate()
如前所述,如果保存的数据很简单,则可以擦除数据库,然后重新创建它。如果有其他数据,可能是用户结果、用户进度或其他任何数据,则需要在onUpgrade中正确处理更新 我通常做的是使用onUpgrade从android资源中读取迁移文件。这些文件将具有数据库模式更改(如果需要)和在版本之间迁移数据库所需的任何更新语句。我宁愿不要下面的case语句,也不要动态地寻找迁移,但这是一个必要的缺点,允许我在必要时定制和调整每个迁移
@Override
public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, int oldVersion, int newVersion)
{
AppLog.i(TAG, "onUpgrade, oldVersion=["+oldVersion+"], newVersion=["+newVersion+"]");
try
{
// Simply loop round until newest version has been reached and add the appropriate migration
while (++oldVersion <= newVersion)
{
switch (oldVersion)
{
// The version in the case statement is the new (target) version. So case 2: will be an upgrade from 2 to 3.
case 2: {
UpgradeUtils.addUpgrade(oldVersion);
break;
}
case 3: {
UpgradeUtils.addUpgrade(oldVersion);
break;
}
case 7: {
UpgradeUtils.addUpgrade(oldVersion);
}
case 8: {
UpgradeUtils.addUpgrade(oldVersion);
}
}
}
// Get all the available updates
final List<String> availableUpdates = UpgradeUtils.availableUpdates(DatabaseHelper.context.getResources());
AppLog.d(TAG, "Found a total of " + availableUpdates.size() +" update statements" );
for (final String statement : availableUpdates)
{
db.beginTransaction();
try {
AppLog.d(TAG, "Executing statement: " + statement);
db.execSQL(statement);
db.setTransactionSuccessful();
}
finally {
db.endTransaction();
}
}
}
catch (Exception e)
{
Log.e(TAG,"Error executing sql while upgrading database", e);
}
}
@覆盖
公共空间升级(SQLi)
@Override
public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, int oldVersion, int newVersion)
{
AppLog.i(TAG, "onUpgrade, oldVersion=["+oldVersion+"], newVersion=["+newVersion+"]");
try
{
// Simply loop round until newest version has been reached and add the appropriate migration
while (++oldVersion <= newVersion)
{
switch (oldVersion)
{
// The version in the case statement is the new (target) version. So case 2: will be an upgrade from 2 to 3.
case 2: {
UpgradeUtils.addUpgrade(oldVersion);
break;
}
case 3: {
UpgradeUtils.addUpgrade(oldVersion);
break;
}
case 7: {
UpgradeUtils.addUpgrade(oldVersion);
}
case 8: {
UpgradeUtils.addUpgrade(oldVersion);
}
}
}
// Get all the available updates
final List<String> availableUpdates = UpgradeUtils.availableUpdates(DatabaseHelper.context.getResources());
AppLog.d(TAG, "Found a total of " + availableUpdates.size() +" update statements" );
for (final String statement : availableUpdates)
{
db.beginTransaction();
try {
AppLog.d(TAG, "Executing statement: " + statement);
db.execSQL(statement);
db.setTransactionSuccessful();
}
finally {
db.endTransaction();
}
}
}
catch (Exception e)
{
Log.e(TAG,"Error executing sql while upgrading database", e);
}
}
public class UpgradeUtils
{
private static final String TAG = "UpgradeHelper";
protected static final Set<Integer> mVersionSet;
static
{
mVersionSet = new LinkedHashSet<Integer>();
}
public static final void addUpgrade(final int version)
{
AppLog.d(TAG, "Adding " + version + " to upgrade path");
mVersionSet.add(version);
}
public static List<String> availableUpdates(final Resources resources)
{
final List<String> updates = new ArrayList<String>();
for (Integer version : mVersionSet)
{
// Migration files are kept in assets/updates/migration-X.sql
String fileName = String.format("updates/migration-%s.sql", version);
AppLog.d(TAG, "Adding db version [" + version + "] to update list, loading file ["+ fileName +"]" );
final String sqlStatements = DBUtils.loadAssetFile(resources, fileName);
final String[] splitSql = sqlStatements.split("\\r?\\n");
for (final String sql : splitSql)
{
if (DBUtils.isNotComment(sql))
{
updates.add(sql);
}
}
}
return updates;
}