android SQLite数据库应用

android SQLite数据库应用

2011-02-26 15:29 143人阅读评论(0) 收藏举报package cn.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;

public class DatabaseAdapter {

private Context mCtx=null;

private DatabaseHelper dbHelper;

private SQLiteDatabase db=null;

private static final String DATABASE_NAME="accountant.db";

private static final int DATABASE_VERSION=1;

private static final String DATABASE_CREATE_1="CREATE TABLE 'aa' "

public DatabaseAdapter(Context mCtx){

this.mCtx=mCtx;

}

public DatabaseAdapter open()throws SQLException{

dbHelper=new DatabaseHelper(mCtx);

db=dbHelper.getWritableDatabase();

return this;

}

public void close(){

dbHelper.close();

}

/**

* 查询所有数据

* @param TableName 表名

* @param cols 查询列名数组

* @return

*/

public Cursor getAll(String TableName , String[] cols){

return db.query(TableName, cols, null, null, null, null, null);

}

/**

* 查询所有数据

* @param TableName 表名

* @param cols 查询列名数组

* @return

*/

public Cursor getByParams(String TableName , String[] cols , String selection , String[] selectionArgs){

return db.query(TableName, cols, selection, selectionArgs, null, null, null);

}

/**

* 添加数据

* @param note

* @return

*/

public long create(String TableName , ContentValues args){

return db.insert(TableName, null, args);

}

/**

* 删除数据

* @param TableName 表名

* @param rowId Id

* @return

*/

public boolean delete(String TableName , long rowId){

return db.delete(TableName, "id = " +rowId, null)>0;

}

/**

* 更新数据

* @param TableName 表名

* @param rowId id

* @param args 数据集

* @return

*/

public boolean update(String TableName , long rowId,ContentValues args){ return db.update(TableName, args, "id = "+rowId, null)>0;

}

/**

* 按照ID查询数据

* @param TableName 表名

* @param rowId ID

* @param cols 列名数组

* @return

* @throws SQLException

*/

public Cursor get(String TableName , long rowId , String[] cols)throws SQLException{ Cursor mCursor=db.query(true, TableName, cols, "id = "+rowId, null, null, null, null, null);

if(mCursor!=null){

mCursor.moveToFirst();

}

return mCursor;

}

/**

* 按照SQL语句查询数据

* @param sql sql语句

* @param args 参数值

* @return

*/

public Cursor getBySQL(String sql , String[] args){

Cursor mCursor = db.rawQuery(sql, args);

return mCursor;

}

/**

* 关闭数据库连接

*/

public void closeDB(){

if(db!= null || db.isOpen()){

db.close();

}

}

/**

* 打开数据库连接

*/

public void openDB(){

if(db == null || !db.isOpen()){

db=dbHelper.getWritableDatabase();

}

}

private static class DatabaseHelper extends SQLiteOpenHelper{ public DatabaseHelper(Context context) {

super(context, DATABASE_NAME, null, DATABASE_VERSION);

}

public void onCreate(SQLiteDatabase db) {

db.execSQL(DATABASE_CREATE_1);

}

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

onCreate(db);

}

}

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { }

}