这是我正在尝试做的,我创建了一个 SQL 数据库来保存一张巨大的饮料表,该表如下所示:
**_ID ALCOHOL TYPE BRAND PRICE**
前任。1 酒 伏特加 斯米尔诺夫 14
这是我的数据库适配器的代码:
package net.learn2develop.Database;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBAdapter {
public static final String KEY_ROWID = "_id";
public static final String KEY_ALCOHOL = "alcohol";
public static final String KEY_TYPE = "type";
public static final String KEY_BRAND = "brand";
public static final String KEY_PRICE = "price";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "booze";
private static final String DATABASE_TABLE = "titles";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE =
"create table titles (_id integer primary key autoincrement, "
+ "alcohol text not null, type text not null, "
+ "brand text not null);" + "price integer not null";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion
+ " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS titles");
onCreate(db);
}
}
//---opens the database---
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
DBHelper.close();
}
//---insert a title into the database---
public long insertTitle(String alcohol, String type, String brand, int price)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_ALCOHOL, alcohol);
initialValues.put(KEY_TYPE, type);
initialValues.put(KEY_BRAND, brand);
initialValues.put(KEY_PRICE, price);
return db.insert(DATABASE_TABLE, null, initialValues);
}
//---deletes a particular title---
public boolean deleteTitle(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID +
"=" + rowId, null) > 0;
}
//---retrieves all the titles---
public Cursor getAllTitles()
{
return db.query(DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_ALCOHOL,
KEY_TYPE,
KEY_BRAND,
KEY_PRICE},
null,
null,
null,
null,
null);
}
//---retrieves a particular title---
public Cursor getTitle(long rowId) throws SQLException
{
Cursor mCursor =
db.query(true, DATABASE_TABLE, new String[] {
KEY_ROWID,
KEY_ALCOHOL,
KEY_TYPE,
KEY_BRAND,
KEY_PRICE
},
KEY_ROWID + "=" + rowId,
null,
null,
null,
null,
null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
//---updates a title---
public boolean updateTitle(long rowId, String alcohol,
String type, String brand, int price)
{
ContentValues args = new ContentValues();
args.put(KEY_ALCOHOL, alcohol);
args.put(KEY_TYPE, type);
args.put(KEY_BRAND, brand);
args.put(KEY_PRICE, price);
return db.update(DATABASE_TABLE, args,
KEY_ROWID + "=" + rowId, null) > 0;
}
}
现在我知道我可以通过调用将它们单独添加到我的主要活动中:
//---add 2 titles---
db.open();
long id;
id = db.insertTitle(
"Liquor",
"Vodka",
"Smirnoff",
"14");
id = db.insertTitle(
"Liquor",
"Rum",
"Captain Morgan",
"20");
db.close();
问题是我有数百个要添加....将它们全部添加到数据库中的最佳方法是什么?提前感谢你们的任何帮助!我还在学习,我以前从未使用过数据库,所以我现在失去了仪式。