sqlite工具种

package com.asc.db;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * 数据库公共类，提供基本数据库操作 *  * @author raymon *  */public class DBManager {	// 默认数据库	private static final String DB_NAME = "asc.db";	// 数据库版本	private static final int DB_VERSION = 1;	// 执行open()打开数据库时，保存返回的数据库对象	private SQLiteDatabase mSQLiteDatabase = null;	// 由SQLiteOpenHelper继承过来	private DatabaseHelper mDatabaseHelper = null;	// 本地Context对象	private Context mContext = null;		private static DBManager dbConn= null;		// 查询游标对象	private Cursor cursor;	/**	 * SQLiteOpenHelper内部类	 */	private static class DatabaseHelper extends SQLiteOpenHelper {		DatabaseHelper(Context context) {			// 当调用getWritableDatabase()或 getReadableDatabase()方法时,创建一个数据库			super(context, DB_NAME, null, DB_VERSION);		}		@Override		public void onCreate(SQLiteDatabase db) {			db.execSQL("CREATE TABLE ad_record(id PRIMARY KEY NOT NULL, adUrl TEXT, apMac TEXT, createDate DATETIME);");		}		@Override		public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {			db.execSQL("DROP TABLE IF EXISTS ad_record");			onCreate(db);		}	}	/**	 * 构造函数	 * 	 * @param mContext	 */	private DBManager(Context mContext) {		super();		this.mContext = mContext;	}		public static DBManager getInstance(Context mContext){		if (null == dbConn) {			dbConn = new DBManager(mContext);		}		return dbConn;	}	/**	 * 打开数据库	 */	public void open() {		mDatabaseHelper = new DatabaseHelper(mContext);		mSQLiteDatabase = mDatabaseHelper.getWritableDatabase();	}	/**	 * 关闭数据库	 */	public void close() {		if (null != mDatabaseHelper) {			mDatabaseHelper.close();		}		if (null != cursor) {			cursor.close();		}	}	/**	 * 插入数据	 * @param tableName 表名	 * @param nullColumn null	 * @param contentValues 名值对	 * @return 新插入数据的ID，错误返回-1	 * @throws Exception	 */	public long insert(String tableName, String nullColumn,			ContentValues contentValues) throws Exception {		try {			return mSQLiteDatabase.insert(tableName, nullColumn, contentValues);		} catch (Exception e) {			throw e;		}	}	/**	 * 通过主键ID删除数据	 * @param tableName 表名	 * @param key 主键名	 * @param id 主键值	 * @return 受影响的记录数	 * @throws Exception	 */	public long delete(String tableName, String key, int id) throws Exception {		try {			return mSQLiteDatabase.delete(tableName, key + " = " + id, null);		} catch (Exception e) {			throw e;		}	}		/**	 * 查找表的所有数据	 * @param tableName 表名	 * @param columns 如果返回所有列，则填null	 * @return	 * @throws Exception	 */	public Cursor findAll(String tableName, String [] columns) throws Exception{		try {			cursor = mSQLiteDatabase.query(tableName, columns, null, null, null, null, null);			cursor.moveToFirst();			return cursor;		} catch (Exception e) {			throw e;		}	}		/**	 * 根据主键查找数据	 * @param tableName 表名	 * @param key 主键名	 * @param id  主键值	 * @param columns 如果返回所有列，则填null	 * @return Cursor游标	 * @throws Exception 	 */	public Cursor findById(String tableName, String key, int id, String [] columns) throws Exception {		try {			return mSQLiteDatabase.query(tableName, columns, key + " = " + id, null, null, null, null);		} catch (Exception e) {			throw e;		}	}		/**	 * 根据条件查询数据	 * @param tableName 表名	 * @param names 查询条件	 * @param values 查询条件值	 * @param columns 如果返回所有列，则填null	 * @param orderColumn 排序的列	 * @param limit 限制返回数	 * @return Cursor游标	 * @throws Exception	 */	public Cursor find(String tableName, String [] names, String [] values, String [] columns, String orderColumn, String limit) throws Exception{		try {			StringBuffer selection = new StringBuffer();			for (int i = 0; i < names.length; i++) {				selection.append(names[i]);				selection.append(" = ?");				if (i != names.length - 1) {					selection.append(",");				}			}			cursor = mSQLiteDatabase.query(true, tableName, columns, selection.toString(), values, null, null, orderColumn, limit);			cursor.moveToFirst();			return cursor;		} catch (Exception e) {			throw e;		}	}		/**	 * 	 * @param tableName 表名	 * @param names 查询条件	 * @param values 查询条件值	 * @param args 更新列-值对	 * @return true或false	 * @throws Exception	 */	public boolean udpate(String tableName, String [] names, String [] values, ContentValues args) throws Exception{		try {			StringBuffer selection = new StringBuffer();			for (int i = 0; i < names.length; i++) {				selection.append(names[i]);				selection.append(" = ?");				if (i != names.length - 1) {					selection.append(",");				}			}			return mSQLiteDatabase.update(tableName, args, selection.toString(), values) > 0;		} catch (Exception e) {			throw e;		}	}		/**	 * 执行sql语句，包括创建表、删除、插入	 * 	 * @param sql	 */	public void executeSql(String sql) {		mSQLiteDatabase.execSQL(sql);	}}//转载请注明出处：http://forhope.iteye.com/blog/1461412