无法在 SQLite Android Eclipse 中创建超过 2 列？

Posted 2023-04-19

【中文标题】无法在 SQLite Android Eclipse 中创建超过 2 列？

【英文标题】：Unable to make more than 2 columns in SQLite Android Eclipse?

【发布时间】：2015-03-24 00:45:26

【问题描述】：

为什么当我的列超过 3 列时，应用程序会崩溃？我尝试通过注释掉一列来调试它，它运行得很好。在对其进行了更多调试后，我发现问题可能出在“populateListview”上，因为我能够运行该应用程序，但现在它不会显示任何内容。为什么你认为我不能用超过 3 列运行它？

这是我的 dbAdapter：

// Field Names:
public static final String KEY_ROWID = "_id";
public static final String KEY_INGREDIENTNAME = "ingredientname";
public static final String KEY_IMAGE = "image";
public static final String KEY_DETAILS = "details";

public static final String[] ALL_KEYS = new String[] KEY_ROWID, KEY_INGREDIENTNAME, KEY_IMAGE, KEY_DETAILS;

// Column Numbers for each Field Name:
public static final int COL_ROWID = 0;
public static final int COL_INGREDIENTNAME = 1;
public static final int COL_IMAGE = 2;
public static final int COL_DETAILS = 3;

//SQL statement to create database
private static final String DATABASE_CREATE_SQL = 
        "CREATE TABLE " + DATABASE_TABLE 
        + " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
        + KEY_INGREDIENTNAME + " TEXT NOT NULL, "
        + KEY_IMAGE + " TEXT"
        + KEY_DETAILS + " TEXT"
        + ");";

// Add a new set of values to be inserted into the database.
public long insertRow(String ingredientname, String image, String detailsValue) 
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_INGREDIENTNAME, ingredientname);
    initialValues.put(KEY_IMAGE, image);
    initialValues.put(KEY_DETAILS, detailsValue);

    // Insert the data into the database.
    return db.insert(DATABASE_TABLE, null, initialValues);


// Return all data in the database.
public Cursor getAllRows() 
    String where = null;
    Cursor c =  db.query(true, DATABASE_TABLE, ALL_KEYS, where, null, null, null, null, null);
    if (c != null) 
        c.moveToFirst();

    
    return c;

这是我的 populateListView 代码：

    private void populateListView() 
    Cursor cursor = myDb.getAllRows();
    String[] fromFieldNames = new String[]  //DBAdapter.KEY_ROWID,
            DBAdapter.KEY_INGREDIENTNAME ;
    int[] toViewIDs = new int[]  //R.id.textViewItemNumber,
            R.id.textViewItemTask ;
    SimpleCursorAdapter myCursorAdapter;
    myCursorAdapter = new SimpleCursorAdapter(getBaseContext(),
            R.layout.item_layout, cursor, fromFieldNames, toViewIDs, 0);
    ListView myList = (ListView) findViewById(R.id.listViewTask);
    myList.setAdapter(myCursorAdapter);

【问题讨论】：

您在日志中遇到的错误是什么。发布您的日志和导致错误的行

【参考方案1】：

你错过了一个逗号，这里：

private static final String DATABASE_CREATE_SQL = 
        "CREATE TABLE " + DATABASE_TABLE 
        + " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
        + KEY_INGREDIENTNAME + " TEXT NOT NULL, "
        + KEY_IMAGE + " TEXT"
        + KEY_DETAILS + " TEXT"
        + ");";

应该是

private static final String DATABASE_CREATE_SQL = 
        "CREATE TABLE " + DATABASE_TABLE 
        + " (" + KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
        + KEY_INGREDIENTNAME + " TEXT NOT NULL, "
        + KEY_IMAGE + " TEXT,"
        + KEY_DETAILS + " TEXT"
        + ");";

【讨论】：

为什么？这只是分心。