Question

我写了一个查询，根据id选择名称和指定字段，然后在片段类中我调用属于相应查询的方法，但不幸的是我得到了Sqlite异常。

数据库方法

public Employee getEmployeeName(int id) {
    SQLiteDatabase db = this.getWritableDatabase();
    Employee employee = new Employee();
    String query ="SELECT  " + KEY_NAME +", " +KEY_DESIG +" FROM " + TABLE_EMPLOYEES+ " WHERE " + KEY_ID + "=" + id;
    Cursor cursor = db.rawQuery(query, null);
    if (cursor.moveToFirst()) {
        do {
            employee.setName(cursor.getString(1));
            employee.setDesignation(cursor.getString(2));
        } while (cursor.moveToNext());
    }
    return employee;

}

从片段中调用

db.getEmployeeName(selectedManager);

异常

01-07 06:02:34.185: E/AndroidRuntime(2386): java.lang.IllegalStateException: Couldn't read row 0, col 2 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.

Answer 1

列索引从零开始。 getString(2)引用第三列，光标只有两列。

更改

employee.setName(cursor.getString(1));
employee.setDesignation(cursor.getString(2));

到

employee.setName(cursor.getString(0));
employee.setDesignation(cursor.getString(1));

Answer 2

试试这个

 if (cursor.moveToFirst()) {
    do {
        employee.setName(cursor.getString(cursor.getColumnIndex(KEY_NAME));
        employee.setDesignation(cursor.getString(cursor.getColumnIndex(KEY_DESIG));
    } while (cursor.moveToNext());
}

使用Cursor

从cursor.getColumnIndex(COLUMN NAME)获取数据

在获取字段时选择“查询”问题

2 个答案: