Question

尝试刷新目录项表..只是一个基本的数据库操作我遇到了一个奇怪的行为

String purgeItems ="DELETE FROM CatalogItems";

String count = "SELECT * FROM CatalogItems";

SQLiteDatabase db = mDb.getWritableDatabase(); // mDb extends SQLiteOpenHelper

db.beginTransaction();
db.rawQuery(purgeItems,null);
db.setTransactionSuccessful();
db.endTransaction();

Cursor c = db.rawQuery(count, null);
Log.e(TAG, "CatalogItems after purge " + String.valueOf(c.getCount()));

返回642：原始表行计数

......！也许我累了^^。它可以与其他表格一起使用..

SQLiteOpenHelper（mDb）创建表代码

private void createTables(SQLiteDatabase db) {
    // --- CATALOG ITEMS ---
    String catalogItemsTable = "CREATE TABLE CatalogItems (" +
            "idCatalogItem      INT(11) PRIMARY KEY, " +
            "idCatalog  INT(11), " +
            "idProduct  INT(11), " +
            "image     BLOB, " +
            "price     FLOAT, " +
            "quantity     INT(11), " +
            "unit     VARCHAR(5), " +
            "status  INT(11), " +
            "extras   VARCHAR(512) " +
            ");" ;

db.execSQL(catalogItemsTable);
Log.i(TAG, "table CatalogItems created");

Answer 1

rawQuery适用于返回行的查询。而是使用：

db.execSQL(purgeItems);

Android SQliteOpenHelper删除语句问题

1 个答案: