android - SQLite 约束异常 : UNIQUE constraint failed

Question

我查看了其他主题，但在代码中找不到我的错误。这是我创建数据库的代码

public class DBHelper extends SQLiteOpenHelper {

    //data base name
    private static final String DATABASE_NAME = "roomatesDB";

    //data base version
    private static final int DATABASE_VERSION = 1;

    //tables name
    public static final String APARTMENT_TABLE = "apartment";
    public static final String ROOMATE_TABLE = "roomate";
    public static final String SHOPCART_TABLE = "shopcart";
    public static final String ITEMS_TABLE = "items";

    //common column
    public static final String APARTMENT_NUMBER_COLUMN = "apartmentNum";

    //roomates table columns
    public static final String FIRST_NAME_COLUMN = "firstName";
    public static final String LAST_NAME_COLUMN = "lastName";
    public static final String PHONE_NUMBER_COLUMN = "phoneNumber";

    //shop cart table columns
    public static final String NUMBER_COLUMN = "number";
    public static final String LIST_NAME_COLUMN = "name";

    //item table
    public static final String PRICE_COLUMN = "price";
    public static final String ITEM_NAME_COLUMN = "name";

    //query for creating roomate table
    public static final String CREATE_ROOMATE_TABLE = "CREATE TABLE "
            + ROOMATE_TABLE + "(" + FIRST_NAME_COLUMN + " TEXT, "
            + LAST_NAME_COLUMN + " TEXT, " + PHONE_NUMBER_COLUMN + " TEXT, "
            + APARTMENT_NUMBER_COLUMN + " INTEGER, "
            + "FOREIGN KEY(" + APARTMENT_NUMBER_COLUMN + ") REFERENCES "
            + APARTMENT_TABLE + "(apartmentNum) " + ")";

    //query for crating shop cart table
    public static final String CREATE_SHOPLIST_TABLE = "CREATE TABLE "
            + SHOPCART_TABLE + "(" + NUMBER_COLUMN + " INTEGER PRIMARY KEY,"
            + LIST_NAME_COLUMN + " TEXT, "
            + APARTMENT_NUMBER_COLUMN + " INTEGER, "
            + "FOREIGN KEY(" + APARTMENT_NUMBER_COLUMN + ") REFERENCES "
            + APARTMENT_TABLE + "(apartmentNum) " + ")";

    //query for creating shop item table
    public static final String CREATE_SHOPITEM_TABLE = "CREATE TABLE "
            + ITEMS_TABLE + "(" + ITEM_NAME_COLUMN + " TEXT,"
            + PRICE_COLUMN + " DOUBLE, "
            + NUMBER_COLUMN + " INT, "
            + "FOREIGN KEY(" + NUMBER_COLUMN + ") REFERENCES "
            + SHOPCART_TABLE + "(number) " + ")";

    //query for creating apartment table
    public static final String CREATE_APARTMENT_TABLE = "CREATE TABLE "
            + APARTMENT_TABLE + "(" + APARTMENT_NUMBER_COLUMN + " INTEGER PRIMARY KEY"
            + ")";


    public DBHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_APARTMENT_TABLE);
        db.execSQL(CREATE_ROOMATE_TABLE);
        db.execSQL(CREATE_SHOPLIST_TABLE);
        db.execSQL(CREATE_SHOPITEM_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + APARTMENT_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + ROOMATE_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + SHOPCART_TABLE);
        db.execSQL("DROP TABLE IF EXISTS " + ITEMS_TABLE);

        onCreate(db);

    }

并检查我是否尝试在 Activity 上执行这些功能

public void createApartment() {
    SQLiteDatabase db = this.getWritableDatabase();



    ContentValues values = new ContentValues();
    values.put(APARTMENT_NUMBER_COLUMN, 1);
    // Inserting Row
    db.insert(APARTMENT_TABLE, null, values);
    db.close(); // Closing database connection
}

public void addRoomate(RoomateModel r) {
        SQLiteDatabase db = this.getWritableDatabase();

        int i = 1;

        ContentValues values = new ContentValues();
        values.put(FIRST_NAME_COLUMN, r.getName()); // Contact Name
        values.put(LAST_NAME_COLUMN, r.getLastName());
        values.put(PHONE_NUMBER_COLUMN, r.getPhoneNumber()); // Contact Phone Number
        values.put(APARTMENT_NUMBER_COLUMN, i);
        // Inserting Row
        db.insert(ROOMATE_TABLE, null, values);
        db.close(); // Closing database connection
    }

    public RoomateModel getRoomates() {
        RoomateModel r = null;
        SQLiteDatabase db = this.getReadableDatabase();
        String query = "SELECT * FROM " + ROOMATE_TABLE + " WHERE 1";

        Cursor c = db.rawQuery(query, null);
        c.moveToFirst();
        while (!c.isAfterLast()) {
            String name = c.getString(0);
            String lastName = c.getString(1);
            String phoneNumber = c.getString(2);
            r = new RoomateModel(name, lastName, phoneNumber);
        }
        if (r == null) {
            r = new RoomateModel("bla", "bla", "bla");
        }

        return r;
    }

应用程序在加载 Activity 之前崩溃主题错误这是日志:

Error Code : 1555 (SQLITE_CONSTRAINT_PRIMARYKEY)
Caused By : Abort due to constraint violation.
(UNIQUE constraint failed: apartment.apartmentNum (code 1555))
#################################################################
at android.database.sqlite.SQLiteConnection.nativeExecuteForLastInsertedRowId(Native Method)
at android.database.sqlite.SQLiteConnection.executeForLastInsertedRowId(SQLiteConnection.java:952)
at android.database.sqlite.SQLiteSession.executeForLastInsertedRowId(SQLiteSession.java:788)
at android.database.sqlite.SQLiteStatement.executeInsert(SQLiteStatement.java:86)
at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1609)
at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1479)
at atoa.roomates.SupportOperations.DBHelper.createApartment(DBHelper.java:106)
at atoa.roomates.QA.getRoomate(QA.java:49)
at atoa.roomates.QA.onCreate(QA.java:42)

Answer 1

您的表上有一个主键，因此它必须是唯一值。

public static final String CREATE_APARTMENT_TABLE = "CREATE TABLE "
        + APARTMENT_TABLE + "(" + APARTMENT_NUMBER_COLUMN + " INTEGER PRIMARY KEY"
        + ")";

然而，您总是在该列中插入值 1。

values.put(APARTMENT_NUMBER_COLUMN, 1);
// Inserting Row
db.insert(APARTMENT_TABLE, null, values);

有几种方法可以解决这个问题，但您应该从使用不同的数字开始，而不是总是使用 1