Android数据库(SqlLite)操作和db文件查看

操作步骤很简单，首先导入sqlLite 的DB文件(即File Explorer   /data /data/)，然后进行各种sql操作。

下面是我的代码：

package com.xiaoshan.udp.client.db;

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;

/**
 * 数据库常用操作的封装类
 *
 * @author 单红宇
 *
 */
public class DBHelper {

	private static DatabaseHelper mDbHelper;
	private static SQLiteDatabase mDb;

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

	private static final int DATABASE_VERSION = 1;

	private final Context mCtx;

	private static class DatabaseHelper extends SQLiteOpenHelper {

		DatabaseHelper(Context context) {
			super(context, DATABASE_NAME, null, DATABASE_VERSION);
		}

		@Override
		public void onCreate(SQLiteDatabase db) {
		}

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

	public DBHelper(Context ctx) {
		this.mCtx = ctx;
	}

	public DBHelper open() throws SQLException {
		mDbHelper = new DatabaseHelper(mCtx);
		mDb = mDbHelper.getWritableDatabase();
		return this;
	}

	/**
	 * 关闭数据源
	 *
	 * @author SHANHY
	 */
	public void closeConnection() {
		if (mDb != null && mDb.isOpen())
			mDb.close();
		if (mDbHelper != null)
			mDbHelper.close();
	}

	/**
	 * 插入数据 参数
	 *
	 * @param tableName
	 *            表名
	 * @param initialValues
	 *            要插入的列对应值
	 * @return
	 * @author SHANHY
	 */
	public long insert(String tableName, ContentValues initialValues) {

		return mDb.insert(tableName, null, initialValues);
	}

	/**
	 * 删除数据
	 *
	 * @param tableName
	 *            表名
	 * @param deleteCondition
	 *            条件
	 * @param deleteArgs
	 *            条件对应的值（如果deleteCondition中有“？”号，将用此数组中的值替换，一一对应）
	 * @return
	 * @author SHANHY
	 */
	public boolean delete(String tableName, String deleteCondition, String[] deleteArgs) {

		return mDb.delete(tableName, deleteCondition, deleteArgs) > 0;
	}

	/**
	 * 更新数据
	 *
	 * @param tableName
	 *            表名
	 * @param initialValues
	 *            要更新的列
	 * @param selection
	 *            更新的条件
	 * @param selectArgs
	 *            更新条件中的“？”对应的值
	 * @return
	 * @author SHANHY
	 */
	public boolean update(String tableName, ContentValues initialValues, String selection, String[] selectArgs) {
		return mDb.update(tableName, initialValues, selection, selectArgs) > 0;
	}

	/**
	 * 取得一个列表
	 *
	 * @param distinct
	 *            是否去重复
	 * @param tableName
	 *            表名
	 * @param columns
	 *            要返回的列
	 * @param selection
	 *            条件
	 * @param selectionArgs
	 *            条件中“？”的参数值
	 * @param groupBy
	 *            分组
	 * @param having
	 *            分组过滤条件
	 * @param orderBy
	 *            排序
	 * @return
	 * @author SHANHY
	 */
	public Cursor findList(boolean distinct, String tableName, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit) {

		return mDb.query(distinct, tableName, columns, selection, selectionArgs, groupBy, having, orderBy, limit);
	}

	/**
	 * 取得单行记录
	 *
	 * @param tableName
	 *            表名
	 * @param columns
	 *            获取的列数组
	 * @param selection
	 *            条件
	 * @param selectionArgs
	 *            条件中“？”对应的值
	 * @param groupBy
	 *            分组
	 * @param having
	 *            分组条件
	 * @param orderBy
	 *            排序
	 * @param limit
	 *            数据区间
	 * @param distinct
	 *            是否去重复
	 * @return
	 * @throws SQLException
	 * @author SHANHY
	 */
	public Cursor findOne(boolean distinct,String tableName, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit) throws SQLException {

		Cursor mCursor = findList(distinct, tableName, columns, selection, selectionArgs, groupBy, having, orderBy, limit);

		if (mCursor != null) {
			mCursor.moveToFirst();
		}
		return mCursor;

	}

	/**
	 * 执行SQL(带参数)
	 *
	 * @param sql
	 * @param args
	 *            SQL中“？”参数值
	 * @author SHANHY
	 */
	public void execSQL(String sql, Object[] args) {
		mDb.execSQL(sql, args);

	}

	/**
	 * 执行SQL
	 *
	 * @param sql
	 * @author SHANHY
	 */
	public void execSQL(String sql) {
		mDb.execSQL(sql);

	}

	/**
	 * 判断某张表是否存在
	 *
	 * @param tabName
	 *            表名
	 * @return
	 */
	public boolean isTableExist(String tableName) {
		boolean result = false;
		if (tableName == null) {
			return false;
		}

		try {
			Cursor cursor = null;
			String sql = "select count(1) as c from sqlite_master where type ='table' and name ='" + tableName.trim() + "'";
			cursor = mDb.rawQuery(sql, null);
			if (cursor.moveToNext()) {
				int count = cursor.getInt(0);
				if (count > 0) {
					result = true;
				}
			}

			cursor.close();
		} catch (Exception e) {
		}
		return result;
	}

	/**
	 * 判断某张表中是否存在某字段(注，该方法无法判断表是否存在，因此应与isTableExist一起使用)
	 *
	 * @param tabName
	 *            表名
	 * @param columnName
	 *            列名
	 * @return
	 */
	public boolean isColumnExist(String tableName, String columnName) {
		boolean result = false;
		if (tableName == null) {
			return false;
		}

		try {
			Cursor cursor = null;
			String sql = "select count(1) as c from sqlite_master where type ='table' and name ='" + tableName.trim() + "' and sql like '%" + columnName.trim() + "%'";
			cursor = mDb.rawQuery(sql, null);
			if (cursor.moveToNext()) {
				int count = cursor.getInt(0);
				if (count > 0) {
					result = true;
				}
			}

			cursor.close();
		} catch (Exception e) {
		}
		return result;
	}

}

测试类的代码：

package com.xiaoshan.udp.client.db;

import android.content.ContentValues;
import android.database.Cursor;
import android.test.AndroidTestCase;

/**
 * 单元测试操作sqlLite的各种sql
 *
 * @author 单红宇
 */
public class TestSqlLite extends AndroidTestCase {

	/**
	 * 创建表
	 *
	 * @throws Exception
	 */
	public void createTable() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();

		String deleteSql = "drop table if exists user ";
		dbHelper.execSQL(deleteSql);

		// id是自动增长的主键，username和 password为字段名， text为字段的类型
		String sql = "CREATE TABLE user (id integer primary key autoincrement, username text, password text)";
		dbHelper.execSQL(sql);
		dbHelper.closeConnection();
	}

	/**
	 * 插入数据
	 *
	 * @throws Exception
	 */
	public void insert() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();

		ContentValues values = new ContentValues(); // 相当于map

		values.put("username", "test");
		values.put("password", "123456");

		dbHelper.insert("user", values);

		dbHelper.closeConnection();
	}

	/**
	 * 更新数据
	 *
	 * @throws Exception
	 */
	public void update() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();
		ContentValues initialValues = new ContentValues();
		initialValues.put("username", "changename"); // 更新的字段和值
		// 第三个参数为条件语句
		dbHelper.update("user", initialValues, "id = ?", new String[] { "1" });

		dbHelper.closeConnection();
	}

	/**
	 * 删除数据
	 *
	 * @throws Exception
	 */
	public void delete() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();

		dbHelper.delete("user", "id =?'", new String[] { "1" });

		dbHelper.closeConnection();
	}

	/**
	 * 增加字段
	 *
	 * @throws Exception
	 */
	public void addColumn() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();

		String updateSql = "alter table user add company text";
		dbHelper.execSQL(updateSql);

		dbHelper.closeConnection();
	}

	/**
	 * 查询列表
	 *
	 * @throws Exception
	 */
	public void selectList() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();

		Cursor returnCursor = dbHelper.findList(false, "user", new String[] { "id", "username", "password" }, "username?", new String[] { "test" }, null, null, "id desc", null);
		while (returnCursor.moveToNext()) {
			String id = returnCursor.getString(returnCursor.getColumnIndexOrThrow("id"));
			String username = returnCursor.getString(returnCursor.getColumnIndexOrThrow("username"));
			String password = returnCursor.getString(returnCursor.getColumnIndexOrThrow("password"));
			System.out.println("id=" + id + ";username=" + username + ";" + password + ";\n");
		}

		dbHelper.closeConnection();
	}

	/**
	 * 某一条信息
	 *
	 * @throws Exception
	 */
	public void selectInfo() throws Exception {
		DBHelper dbHelper = new DBHelper(this.getContext());
		dbHelper.open();
		Cursor returnCursor = dbHelper.findOne(false,"user", new String[] { "id", "username", "password" }, "id = '1'", null, null, null, "id desc",null);
		if (returnCursor != null) {
			String id = returnCursor.getString(returnCursor.getColumnIndexOrThrow("id"));
			String username = returnCursor.getString(returnCursor.getColumnIndexOrThrow("username"));
			String password = returnCursor.getString(returnCursor.getColumnIndexOrThrow("password"));
			System.out.println("id=" + id + ";username=" + username + ";" + password + ";\n");
		}
	}
}

另外，sqllite数据库的db文件可以直接使用工具查看，具体工具是SQLiteSpy

如上代码和SQLiteSpy.exe查看下载地址为：http://download.csdn.net/detail/catoop/4319241