这是错误...
12-17 17:17:30.729: E/SQLiteDatabase(21112): Error inserting nome=categoriaTest
12-17 17:17:30.729: E/SQLiteDatabase(21112): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.database.sqlite.SQLiteStatement.native_executeInsert(Native Method)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.database.sqlite.SQLiteStatement.executeInsert(SQLiteStatement.java:113)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1844)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1717)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at com.ggservice.democracy.pollDataSource.createCategoria(pollDataSource.java:40)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at com.ggservice.democracy.MainActivity.onClick(MainActivity.java:44)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at java.lang.reflect.Method.invokeNative(Native Method)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at java.lang.reflect.Method.invoke(Method.java:511)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.view.View$1.onClick(View.java:3064)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.view.View.performClick(View.java:3591)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.view.View$PerformClick.run(View.java:14263)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.os.Handler.handleCallback(Handler.java:605)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.os.Handler.dispatchMessage(Handler.java:92)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.os.Looper.loop(Looper.java:137)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at android.app.ActivityThread.main(ActivityThread.java:4507)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at java.lang.reflect.Method.invokeNative(Native Method)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at java.lang.reflect.Method.invoke(Method.java:511)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
12-17 17:17:30.729: E/SQLiteDatabase(21112): at dalvik.system.NativeStart.main(Native Method)
虽然，应该这样做的按钮就像：
public void onClick(View view) {
@SuppressWarnings("unchecked")
ArrayAdapter<categorie> adapter = (ArrayAdapter<categorie>) getListAdapter();
categorie categoria = null;
switch (view.getId()) {
case R.id.add:
// Save the new comment to the database
categoria = datasource.createCategoria("categoriaTest");
adapter.add(categoria);
break;
}
adapter.notifyDataSetChanged();
}
，createCategoria就像：
public categorie createCategoria(String categoria) {
ContentValues values = new ContentValues();
values.put(MySQLiteHelper.COLUMN_NOME, categoria);
long insertId = database.insert(MySQLiteHelper.TABLE_CATEGORIE, null,
values);
Cursor cursor = database.query(MySQLiteHelper.TABLE_CATEGORIE,
allCategorieColumns, MySQLiteHelper.COLUMN_ID + " = " + insertId, null,
null, null, null);
cursor.moveToFirst();
categorie newCategoria = cursorToCategorie(cursor);
cursor.close();
return newCategoria;
}
SQliteHelper：
public class MySQLiteHelper extends SQLiteOpenHelper {
public static final String TABLE_CATEGORIE = "categorie";
public static final String TABLE_SONDAGGI = "sondaggi";
public static final String TABLE_TESTORISPOSTE = "testo_risposte";
public static final String TABLE_RISPOSTE = "risposte";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_NOME = "nome";
public static final String COLUMN_PREF = "preferita";
public static final String COLUMN_CATID = "catid";
public static final String COLUMN_DOMANDA = "domanda";
public static final String COLUMN_SONDID = "sondid";
public static final String COLUMN_RISPOSTA = "risposta";
public static final String COLUMN_RISID = "risid";
public static final String COLUMN_SELEZIONATA = "selezionata";
private static final String DATABASE_NAME = "democracy.db";
private static final int DATABASE_VERSION = 2;
// Database creation sql statement
private static final String DATABASE_CREATE_CATEGORIE = "create table "
+ TABLE_CATEGORIE + "(" + COLUMN_ID
+ " integer primary key autoincrement, " + COLUMN_PREF
+ " integer not null, " + COLUMN_NOME
+ " text not null);";
private static final String DATABASE_CREATE_SONDAGGI = "create table "
+ TABLE_SONDAGGI + "(" + COLUMN_ID
+ " integer primary key autoincrement, " + COLUMN_CATID
+ " integer not null, "+ COLUMN_DOMANDA +" text not null);";
private static final String DATABASE_CREATE_TESTORISPOSTE = "create table "
+ TABLE_TESTORISPOSTE + "(" + COLUMN_ID
+ " integer primary key autoincrement, " + COLUMN_SONDID
+ " integer not null, "+ COLUMN_SELEZIONATA
+ " integer not null, "+ COLUMN_RISPOSTA +" text not null);";
public MySQLiteHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL(DATABASE_CREATE_CATEGORIE);
database.execSQL(DATABASE_CREATE_SONDAGGI);
database.execSQL(DATABASE_CREATE_TESTORISPOSTE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(MySQLiteHelper.class.getName(),
"Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CATEGORIE);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_SONDAGGI);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_TESTORISPOSTE);
onCreate(db);
}
}
我不知道你是否还需要更多东西，我在android上是一个相当的菜鸟，但我想要了解，我实际上是想通过添加实际应用中的“转换”教程更多的桌子，制作一个好的DAO等等...... 你有什么建议吗？ 附：有没有办法“看”我可能“在设备中”创建的数据库？
答案 0 :(得分：1)
问题是您的列COLUMN_PREF不能为空，并且您通过不插入任何内容在方法中插入null：
COLUMN_PREF + " integer not null,"
-
ContentValues values = new ContentValues();
values.put(MySQLiteHelper.COLUMN_NOME, categoria);
long insertId = database.insert(MySQLiteHelper.TABLE_CATEGORIE, null, values);
只需将该值添加到插入或删除'not null'子句。