Android Sqlite数据库操作

Android中的数据存储方式有:SharedPreferences 首选项,文件,网络,sqllite;

很多时候开发APP时需要缓存数据,其中以SQL为最常用了. 在此记录一下sql的各种方法.

　 创建本地数据库与表时,需要写一个数据库帮助类继承SQLiteOpenHelper类.

public class DbHelper extends SQLiteOpenHelper

重写方法onCreate(),onUpgrade();

/**
* 首次创建数据库时调用 第一次调用后不再调用
*
* */
@Override
public void onCreate(SQLiteDatabase sdb) {}

/** 此方法用于数据更新表结构 */
@Override
public void onUpgrade(SQLiteDatabase sdb, int oldVersion, int newVersion) {
Log.i(TAG, "更新表结构...");
}

贴一个使用实例:

/**
* @category 入库记录
*
* */
public class DbPutStorage {
private static final String TAG = "DbPutStorage";

private DbHelper helper;
private SQLiteDatabase db;

private static final String TABLE_NAME = "putStorage";

private static DbPutStorage dbPutStorage;

public static DbPutStorage getInstance(Context mContext) {
if (null == dbPutStorage) {
dbPutStorage = new DbPutStorage(mContext);
}
return dbPutStorage;
}

public DbPutStorage(Context mContext) {
helper = new DbHelper(mContext);
// 因为getWritableDatabase内部调用了mContext.openOrCreateDatabase(mName, 0,
// mFactory);
// 所以要确保context已初始化,我们可以把实例化DBManager的步骤放在Activity的onCreate里
db = helper.getWritableDatabase();
}

/**
* 添加一条数据
*
* @param status:上传状态(0:未上传,1:已上传),logoNo:订单标识
* */
public synchronized void addSingle(String logoNo,String _id,
String name, String description, String productCode, String order,
String price, String originalPrice, double quantiy,int status) {
db = helper.getWritableDatabase();
Log.i(TAG, "添加单条数据到临时表");
ContentValues cv = new ContentValues();
cv.put("logoNo", logoNo);
cv.put("pro_id", _id);
cv.put("name", name);
cv.put("description", description);
cv.put("productCode", productCode);
cv.put("orderNo", order);
cv.put("price", price);
cv.put("originalPrice", originalPrice);
cv.put("quantiy", quantiy);
cv.put("status", status);
db.insert(TABLE_NAME, null, cv);
cv.clear();
}

/**
* 查询所有数据
*
* */
public Cursor selectAll() {
db = helper.getWritableDatabase();
Cursor c = db.query(TABLE_NAME, null, null, null, null, null, null);
return c;
}

/**
* 修改某条数据状态
*
* */
public void updateStatus(String pro_id){
db = helper.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("status", 1);
String[] args = {String.valueOf(pro_id)};
db.update(TABLE_NAME, cv, "pro_id=?",args);
}

/**
* 通过rawQuery实现参数查询
*
* @category 根据商品code查询详情
* */
public Cursor queryByCode(String search_context) {
db = helper.getWritableDatabase();
String sql = "select * from " + TABLE_NAME + " where productCode=?";
String[] selectionArgs = new String[] { search_context };
Cursor cursor = db.rawQuery(sql, selectionArgs);
Log.i(TAG, "根据商品code(" + search_context + ")查询" + cursor.getCount());
return cursor;
}

/**
* 通过rawQuery实现参数查询
*
* @category 根据时间date查询详情
* */
public Cursor queryByDate(String search_context) {
db = helper.getWritableDatabase();
String sql = "select * from " + TABLE_NAME + " where date=?";
String[] selectionArgs = new String[] { search_context };
Cursor cursor = db.rawQuery(sql, selectionArgs);
Log.i(TAG, "根据时间date(" + search_context + ")查询" + cursor.getCount());
return cursor;
}

/**
* 通过rawQuery实现模糊参数查询
*
* @category 根据商品名称查询
* */
public Cursor queryName(String search_context) {

db = helper.getWritableDatabase();
String sql = "select * from " + TABLE_NAME + " where name like ?";
String[] selectionArgs = new String[] { "%" + search_context + "%" };
Cursor cursor = db.rawQuery(sql, selectionArgs);
// if (cursor.moveToFirst()) {
// return cursor;
// }
Log.i(TAG, "根据商品名称查询" + cursor.getCount());
return cursor;
}

/**
* 通过rawQuery实现模糊参数查询
*
* @category 根据商品标签查询
* */
public Cursor queryTagId(String search_context) {

db = helper.getWritableDatabase();
String sql = "select * from " + TABLE_NAME + " where productTag like ?";
String[] selectionArgs = new String[] { "%" + search_context + "%" };
Cursor cursor = db.rawQuery(sql, selectionArgs);
Log.i(TAG, "根据商品标签查询" + cursor.getCount());
return cursor;
}

/**
* 通过rawQuery实现模糊参数查询
*
* @category 根据商品名称或者商品code模糊查询
* */
public Cursor query(String search_context) {
db = helper.getWritableDatabase();
String sql = "select * from " + TABLE_NAME
+ " where  name like ? or productCode like ?";
String[] selectionArgs = new String[] { "%" + search_context + "%",
"%" + search_context + "%" };
Cursor cursor = db.rawQuery(sql, selectionArgs);
Log.i(TAG, "模糊查询" + cursor.getCount());
return cursor;
}

/**
* 判断该条记录是否已存在
*
* */
public boolean judgeCode(String code) {
db = helper.getWritableDatabase();
Cursor c = db.rawQuery("select * from " + TABLE_NAME
+ " where productCode=?", new String[] { code });
if (c.moveToFirst()) {
int i = c.getCount();
if (i > 0) {
return true;
}
}
return false;
}

/**
* 删除一条指定数据
*
* */
public void deleteCodeSingle(String productCode) {
db = helper.getWritableDatabase();
String whereClause = "productCode=?";// 删除的条件
String[] whereArgs = { productCode };// 删除的条件参数
Log.i(TAG, "删除一条指定数据");
db.delete(TABLE_NAME, whereClause, whereArgs);// 执行删除
}

/**
* 删除状态为已上传的数据
*
* */
public void deleteStatus(String status){
db = helper.getWritableDatabase();
String whereClause = "status=?";// 删除的条件
String[] whereArgs = { status };// 删除的条件参数
Log.i(TAG, "删除一条已上传的数据");
db.delete(TABLE_NAME, whereClause, whereArgs);// 执行删除
}

/**
* 删除全部数据
*
* */
public void deleteTableData() {
db = helper.getWritableDatabase();
String sql = "delete  from " + TABLE_NAME;// 删除操作的SQL语句
Log.i(TAG, "删除sql所有数据...");
db.execSQL(sql);// 执行删除操作
}

/**
* close database 关闭数据库
*/
public void closeDB() {
db = helper.getWritableDatabase();
db.close();
}
}