我建立了一个表public static final String CREATE_BOOK = "create table Book(" + "id integer primary key autoincrement," + "author text," + "price real," + "pages integer," + "name text," + "category_id integer)";
之后建立了一个Button传入数据
add_data.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SQLiteDatabase db = dbhelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("author", "jose");
values.put("name", "Thank you!");
values.put("pages", 999);
values.put("price", 99.9);
db.insert("Book", null, values); }
});
之后建立另一个按钮用来索引表
query_data.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SQLiteDatabase db = dbhelper.getWritableDatabase();
Cursor cursor = db.query("Book", null, null, null, null, null, null);
if(cursor.moveToFirst()){
do {
String name = cursor.getString(cursor.getColumnIndex("name"));
String author = cursor.getString(cursor.getColumnIndex("author"));
int pages = cursor.getInt(cursor.getColumnIndex("pages"));
double price = cursor.getDouble(cursor.getColumnIndex("price"));
Log.d("MainActivity", "book name is" + name);
Log.d("MainActivity", "book author is" + author);
Log.d("MainActivity", "book pages is" + pages);
Log.d("MainActivity", "book prices is" + price);
}while (cursor.moveToNext());
}
cursor.close();
}
});
但是调试时报错Failed to read row 0, column -1 from a CursorWindow which has 1 rows, 5 columns. Make sure the Cursor is initialized correctly before accessing data from it.
我将传入数据时的name和author的顺序交换之后发现就可以运行了,请教一下各位大神这是什么原因?
欢迎选择我的课程,让我们一起见证您的进步~~