android - onCreate或insert上的onCreate问题

Question

我的这段应用程序让我很伤心.要么我的表没有被正确创建，要么insert语句不符合行。我遵循了本教程，它似乎得到了很好的解释http://www.giantflyingsaucer.com/blog/?p=1342，但我似乎找不到我的代码和他们的区别。任何建议都将不胜感激！

以下是我的MainActivity代码：

SQLiteIngAssistant sqlliteIngAssistant；

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    sqlliteIngAssistant = new SQLiteIngAssistant(MainActivity.this);
    sqlliteIngAssistant.openDB();

    sqlliteIngAssistant.insertIng("Foo");
    String[] autofillIngs = sqlliteIngAssistant.getAllIngNames();

}

这里是我的SQL助手：

public class SQLiteIngAssistant extends SQLiteOpenHelper {
    private static final String DB_NAME = "usingsqlite.db";
    private static final int DB_VERSION_NUMBER = 1;
    private static final String DB_TABLE_NAME = "ings";
    private static final String DB_COLUMN_1_NAME = "ing_name";
    private static final String DB_COLUMN_2_NAME = "cons";

    private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
            " (_id string primary key " + DB_COLUMN_1_NAME + ", " + DB_COLUMN_2_NAME + " text not null);)";

    private SQLiteDatabase sqliteDBInstance = null;

    public SQLiteIngAssistant(Context context){
        super(context, DB_NAME, null, DB_VERSION_NUMBER);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
        // TODO: Implement onUpgrade
    }

    @Override
    public void onCreate(SQLiteDatabase sqliteDBInstance){
        Log.i("onCreate", "Creating the database...");
        sqliteDBInstance.execSQL(DB_CREATE_SCRIPT);
    }

    public void openDB() throws SQLException{
        Log.i("openDB", "Checking sqliteDBInstance...");
        if(this.sqliteDBInstance == null){
            Log.i("openDB", "Creating sqliteDBInstance...");
            this.sqliteDBInstance = this.getWritableDatabase();
        }
    }

    public long insertIng(String Name){
        ContentValues contentValues = new ContentValues();
        contentValues.put(DB_COLUMN_1_NAME, Name);
        return this.sqliteDBInstance.insert(DB_TABLE_NAME, null, contentValues);
    }


    public String[] getAllIngNames(){
        Cursor cursor = this.sqliteDBInstance.query(DB_TABLE_NAME, new String[] {DB_COLUMN_1_NAME}, null, null, null, null, null);

        if(cursor.getCount() >0){
            String[] str = new String[cursor.getCount()];
            int i = 0;

            while (cursor.moveToNext()){
                str[i] = cursor.getString(cursor.getColumnIndex(DB_COLUMN_1_NAME));
                i++;
            }
            return str;
        } else {
            return new String[] {};
        }
    }
}

下面是堆栈跟踪：

01-11 19:23:04.382  14630-14630/com.example.ciltkick.nom E/SQLiteDatabase﹕ Error inserting ing_name=Foo
    android.database.sqlite.SQLiteException: table ings has no column named ing_name (code 1): , while compiling: INSERT INTO ings(ing_name) VALUES (?)
            at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
            at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
            at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
            at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
            at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
            at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
            at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1475)
            at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1347)
            at com.example.ciltkick.nom.SQLiteIngAssistant.insertIng(SQLiteIngAssistant.java:61)
            at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:65)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
            at android.app.ActivityThread.access$600(ActivityThread.java:138)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:213)
            at android.app.ActivityThread.main(ActivityThread.java:4787)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
            at dalvik.system.NativeStart.main(Native Method)
01-11 19:23:04.422  14630-14630/com.example.ciltkick.nom E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ciltkick.nom/com.example.ciltkick.nom.MainActivity}: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2071)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
            at android.app.ActivityThread.access$600(ActivityThread.java:138)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:213)
            at android.app.ActivityThread.main(ActivityThread.java:4787)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: android.database.sqlite.SQLiteException: no such column: ing_name (code 1): , while compiling: SELECT ing_name FROM ings
            at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
            at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
            at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
            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:1322)
            at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1169)
            at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1040)
            at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1208)
            at com.example.ciltkick.nom.SQLiteIngAssistant.getAllIngNames(SQLiteIngAssistant.java:89)
            at com.example.ciltkick.nom.MainActivity.onCreate(MainActivity.java:77)
            at android.app.Activity.performCreate(Activity.java:5008)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2035)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2096)
            at android.app.ActivityThread.access$600(ActivityThread.java:138)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1207)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:213)
            at android.app.ActivityThread.main(ActivityThread.java:4787)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:556)
            at dalvik.system.NativeStart.main(Native Method)

Answer 1

私有静态最终字符串DB_CREATE_SCRIPT = "create“+ DB_TABLE_NAME + (_id String主键”+ DB_COLUMN_1_NAME +“、”+ DB_COLUMN_2_NAME +“text not null)；

在上一列def的,与下面的DB_COLUMN_1_NAME之间缺少一个DB_COLUMN_1_NAME。

添加后，卸载您的应用程序重新创建数据库。

我想要DB_COLUMN_1_NAME作为主键的名称，我如何做到这一点？

将其改为类似的

private static final String DB_CREATE_SCRIPT = "create table " + DB_TABLE_NAME +
        " (" + DB_COLUMN_1_NAME + " string primary key," + DB_COLUMN_2_NAME + " text not null);)";

它还移除您以前拥有的主键列_id。

或者我可以不使用主键访问一行？

是的，您可以根据任何标准选择行。不过，请记住，如果您拥有“大量”数据，并且使用非索引列进行查找，那么性能将非常糟糕。主键列将自动编入索引。