Android 如何在sqlite中匹配两个表的列,以及如何根据匹配检索数据?
这是我的两张桌子-Android 如何在sqlite中匹配两个表的列,以及如何根据匹配检索数据?,android,Android,这是我的两张桌子- private static final String SQL_CREATE_RETAIL_DB_PRODUCT = "CREATE TABLE " + DatabaseContract.RetailDatabaseEntry.TABLE_NAME_PRODUCT + " (" + DatabaseContract.RetailDatabaseEntry.COLU
private static final String SQL_CREATE_RETAIL_DB_PRODUCT =
"CREATE TABLE " + DatabaseContract.RetailDatabaseEntry.TABLE_NAME_PRODUCT + " (" +
DatabaseContract.RetailDatabaseEntry.COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
DatabaseContract.RetailDatabaseEntry.COLUMN_PRODUCT_ID + INTEGER_TYPE + COMMA_SEP +
DatabaseContract.RetailDatabaseEntry.COLUMN_NAME + TEXT_TYPE + COMMA_SEP +
DatabaseContract.RetailDatabaseEntry.COLUMN_IMAGE + BLOB_TYPE + COMMA_SEP +
DatabaseContract.RetailDatabaseEntry.COLUMN_QUANTITY + INTEGER_TYPE + COMMA_SEP +
DatabaseContract.RetailDatabaseEntry.COLUMN_PRICE + INTEGER_TYPE +
" )";
private static final String SQL_CREATE_RETAIL_DB_SCAN =
"CREATE TABLE " + DatabaseContract.RetailDatabaseEntry.TABLE_NAME_SCAN + " (" +
DatabaseContract.RetailDatabaseEntry.COLUMN_PRODUCTID_ID + INTEGER_TYPE + ")";
我想将product table的列productid与scan table的productid匹配。
根据匹配情况,我必须检索数据
由于我是android新手,请向我推荐解决方案。从第一个表中检索产品id的值,并使用where子句示例select*from where productid=(第一个表的产品id)在第二个表中进行查询如何从select查询中的第一个表中获取产品id值。我不知道,因为我是android中sqlite数据库的新手。u告诉我如何检索数据。但告诉我如何匹配这两个列。DatabaseHelper dbhelper=新DatabaseHelper(上下文);dbHelper=新的DatabaseHelper(此);db=dbHelper.getReadableDatabase();Cursor Cursor=db.query(TableName,null,null,null,null,null);而(cursor.moveToNext(){productId=cursor.getString(cursor.getColumnIndex(productId));}您可以在第二个表中使用产品id,如db.query(TableName,null,“productId=?”,新字符串[]{productId of first table},null,null); if(cursor.moveToFirst()){get all column value