Android开始之数据库存储 SQLite

--------------------DBHelper---------------------------

package com.example.android_sqlite_demo1.db;

import android.content.Context;
import android.database.DatabaseErrorHandler;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;

public class DBHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "mydb.db";// 数据库名字.db结束
    private static final int VERSION = 2;// 数据库版本

    public DBHelper(Context contex) {
        super(contex, DB_NAME, null, VERSION);
        // TODO Auto-generated constructor stub
    }

    // .SQLite数据类型：varchar int long float boolean text blob clob: 类型不确认
    // 主键：整型，自动增长；其他用varchar
    // onCreate先执行，且只被执行一次
    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String sql = "create table person(pid integer primary key autoincrement,name varchar(64),address varchar(64))";
        db.execSQL(sql);// 执行
    }

    // 数据库版本更新：增加字段，更改。增删表。：VERSION = 2新版本
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        String sql = "alter table person add age integer";
        db.execSQL(sql);
    }

    // 每次insert 都调用
    public void onOpen(SQLiteDatabase db) {
        super.onOpen(db);
        System.out.println("---->>onopen..");

    }
}

---------------------------DBManager-----------------------------------------

package com.example.android_sqlite_demo1.db;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.R.integer;
import android.R.string;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.UrlQuerySanitizer.ValueSanitizer;

public class DBManager {
    private SQLiteDatabase database;
    private DBHelper helper;

    public DBManager(Context context) {
        // TODO Auto-generated constructor stub
        helper = new DBHelper(context);
        //database = helper.getWritableDatabase();
        
        
        
        // helper.getReadableDatabase();
        // helper.getWritableDatabase();
    }

    // 实现对数据库的添加，删除和修改功能
    public boolean updateBySQL(String sql, Object[] bindArgs) {
        boolean flag = false;

        try {

            database.execSQL(sql, bindArgs);
            flag = true;
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        } 
        
        return flag;
    }
    //获得数据库的连接
    public void getDataBaseConn(){
        database = helper.getWritableDatabase();
        
        
    }
    public void releaseConn(){
        
        if(database!=null){database.close();}
        
    }
    

    // 插入
    public boolean insert(String table, String nullColumnHack,
            ContentValues values) {
        boolean flag = false;
        // insert into tableName(a,b,c)values(?,?,?);
        long id = database.insert(table, nullColumnHack, values);
        flag = (id > 0 ? true : false);
        return flag;

    }

    // tableName set name=?,address=?,age=? where pid=?
    public boolean update(String table, ContentValues values,
            String whereClause, String[] whereArgs) {
        boolean flag = false;
        int count = database.update(table, values, whereClause, whereArgs);
        flag = (count > 0 ? true : false);
        return flag;
    }

    // delete from tableName where pid=?
    public boolean delete(String table, String whereClause, String[] whereArgs) {
        boolean flag = false;
        int count = database.delete(table, whereClause, whereArgs);
        flag = (count > 0 ? true : false);
        return flag;
    }

    // sql标准：select [distinct][列名].. from tableName
    // [where][selection][selectionArgs][groupBy][ having][orderBy][limit]
    // [distinct] 去掉重复记录
    // table： 表名columns： 列名 selection ：查询的过滤条件 selectionArgs：
    // 过滤条件的值 groupBy：分组 having：对分组进行条件过滤 orderBy：排序 limit：分页

    public Cursor query(boolean distinct, String table, String[] columns,
            String selection, String[] selectionArgs, String groupBy,
            String having, String orderBy, String limit) {
        Cursor cursor = null;
        cursor = database.query(distinct, table, columns, selection,
                selectionArgs, groupBy, having, orderBy, limit);
        return cursor;
    }

    // 对数据库的某一行记录查询
    public Map<String, String> queryBySQL(String sql, String[] selectionArgs) {
        Map<String, String> map = new HashMap<String, String>();
        Cursor cursor = database.rawQuery(sql, selectionArgs);
        int cols_len = cursor.getColumnCount();// 列数
        while (cursor.moveToNext()) {

            // System.out.println("---->>"+cursor.getString(cursor.getColumnIndex("name")));
            // System.out.println("---->>"+cursor.getString(cursor.getColumnIndex("address")));
            // System.out.println("---->>"+cursor.getInt(cursor.getColumnIndex("age")));
            for (int i = 0; i < cols_len; i++) {
                String cols_name = cursor.getColumnName(i);
                String cols_value = cursor.getString(cursor
                        .getColumnIndex(cols_name));
                if (cols_value == null) {
                    cols_value = "";

                }
                map.put(cols_name, cols_value);
            }
        }
        return map;
    }

    // 对数据库的整个记录查询
    public List<Map<String, String>> queryMultiMaps(String sql,
            String[] selectionArgs) {
        List<Map<String, String>> list = new ArrayList<Map<String, String>>();
        Cursor cursor = database.rawQuery(sql, selectionArgs);
        int cols_len = cursor.getColumnCount();
        while (cursor.moveToNext()) {
            Map<String, String> map = new HashMap<String, String>();
            for (int i = 0; i < cols_len; i++) {
                String cols_name = cursor.getColumnName(i);
                String cols_value = cursor.getString(cursor
                        .getColumnIndex(cols_name));
                if (cols_value == null) {
                    cols_value = "";

                }
                map.put(cols_name, cols_value);
            }
            list.add(map);
        }
        return list;

    }

    public Cursor queryMultiCursor(String sql, String[] selectionArgs) {
        Cursor cursor = database.rawQuery(sql, selectionArgs);
        return cursor;

    }

    // cls:通过反射获得数据库的查询记录
    // 声明Class的属性必须为String类型
    public <T> T querySingleCursor(String sql, String[] selectionArgs,
            Class<T> cls) {
        T t = null;

        Cursor cursor = database.rawQuery(sql, selectionArgs);
        int cols_len = cursor.getColumnCount();// 列数
        while (cursor.moveToNext()) {
            try {
                t = cls.newInstance();

                for (int i = 0; i < cols_len; i++) {
                    String cols_name = cursor.getColumnName(i);
                    String cols_value = cursor.getString(cursor
                            .getColumnIndex(cols_name));
                    if (cols_value == null) {
                        cols_value = "";

                    }
                    Field field = cls.getDeclaredField(cols_name);
                    field.setAccessible(true);
                    field.set(t, cols_value);
                }
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
            }
        }
        return t;
    }

    public <T> List<T> querMultiCursor(String sql, String[] selectionArgs,
            Class<T> cls) {

        List<T> list = new ArrayList<T>();
        Cursor cursor = database.rawQuery(sql, selectionArgs);
        int cols_len = cursor.getColumnCount();// 列数
        while (cursor.moveToNext()) {
            try {
                T t = cls.newInstance();

                for (int i = 0; i < cols_len; i++) {
                    String cols_name = cursor.getColumnName(i);
                    String cols_value = cursor.getString(cursor
                            .getColumnIndex(cols_name));
                    if (cols_value == null) {
                        cols_value = "";

                    }

                    Field field = cls.getDeclaredField(cols_name);
                    field.setAccessible(true);
                    field.set(t, cols_value);
                    list.add(t);
                }
            } catch (Exception e) {
                // TODO: handle exception
                e.printStackTrace();
            }
        }
        return list;
    }
}

--------------------------单元测试------------------------------------------

package com.example.android_sqlite_demo1;

import java.util.List;

public class MyText extends AndroidTestCase {

    public MyText() {
        // TODO Auto-generated constructor stub
    }

    public void initTable() {
        DBHelper dbManager = new DBHelper(getContext());
        dbManager.getReadableDatabase();
        // dbManager.getWritableDatabase();

    }

    public void insert() {
        String sql = "insert into person(name,address,age)values(?,?,?)";
        Object[] bindArgs = { "张三", "重庆", 34 };
        DBManager manager = new DBManager(getContext());
        manager.updateBySQL(sql, bindArgs);
    }

    public void update() {
        String sql = "update person set name=?,address=?,age=? where pid=?";
        Object[] bindArgs = { "zy", "河北", 21, 1 };
        DBManager manager = new DBManager(getContext());
        manager.updateBySQL(sql, bindArgs);
    }

    public void delete() {
        String sql = "delete from person  where pid=?";
        Object[] bindArgs = { 1 };
        DBManager manager = new DBManager(getContext());
        manager.updateBySQL(sql, bindArgs);
    }

    public void query() {
        String sql = "select * from person ";
        DBManager manager = new DBManager(getContext());
        manager.queryBySQL(sql, null);
    }

    public void query2() {
        String sql = "select * from person where pid=?";
        DBManager manager = new DBManager(getContext());
        Map<String, String> map = manager.queryBySQL(sql, new String[] { "1" });
        System.out.println("---->>" + map.get("name"));
        System.out.println("---->>" + map.get("address"));
        System.out.println("---->>" + map.get("age"));
    }

    public void query3() {
        String sql = "select * from person where name like ?";
        DBManager manager = new DBManager(getContext());
        List<Map<String, String>> list = manager.queryMultiMaps(sql,
                new String[] { "%张%" });
        for (Map<String, String> map2 : list) {

            System.out.println("---->>" + map2.get("name"));
            System.out.println("---->>" + map2.get("address"));
            System.out.println("---->>" + map2.get("age"));

        }

    }

    public void insert2() {

        DBManager manager = new DBManager(getContext());
        ContentValues values = new ContentValues();
        values.put("name", "xx");
        values.put("address", "xxx");
        values.put("age", 44);

        manager.insert("person", null, values);
    }

    public void update2() {

        DBManager manager = new DBManager(getContext());
        ContentValues values = new ContentValues();
        values.put("name", "ff");
        values.put("address", "ffff");
        values.put("age", 44);
        manager.update("person", values, "pid=? ", new String[] { "5" });
    }

    public void delete2() {

        DBManager manager = new DBManager(getContext());
        manager.delete("person", "pid=?", new String[] { "5" });
    }
    
    public void query4() {

        DBManager manager = new DBManager(getContext());
        manager.getDataBaseConn();
        Cursor cursor=manager.query(false,"person", null, null, null, null, null, null,null);
    while(cursor.moveToNext()){
        
        System.out.println("---->>"+cursor.getString(cursor.getColumnIndex("name")));
    }
    manager.releaseConn();
    }
}

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