Android之Sqlite数据库

数据库访问完毕后，游标必须也记得关闭

import com.huangzhong.love_power_model.UserInfoDto;
import java.util.ArrayList;
import java.util.List;
import android.app.AlertDialog;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class UserInfoDao{

    private static final int MODE_PRIVATE = 0x0;
    private static final String DATABASE = "lovepower";
    private static SQLiteDatabase db;

    public static void insert(Context context,UserInfoDto model) {
        //Id,UserName,Birthday,PhoneNumber,QQ,Address,CreateDate
        Cursor cursor;
        int count = ;
        try {
             db = context.openOrCreateDatabase(DATABASE, MODE_PRIVATE, null);
             //db.execSQL("drop table UserInfo ;");
             String sqlCheckExsit = "select count(*) as c from Sqlite_master  where type ='table' and name ='UserInfo' ";
             cursor = db.rawQuery(sqlCheckExsit, null);   

             if(cursor.moveToNext()){
                     count = cursor.getInt();
                     if(count <= ){
                             db.execSQL("Create table UserInfo (Id text not null,UserName text,Birthday text,PhoneNumber text,QQ text,Address text,CreateDate text);");
                             Log.e("insertSql", "");
                     }
             }
             String insertSql = "insert into UserInfo (Id,UserName,Birthday,PhoneNumber,QQ,Address,CreateDate) " +
                        "values('" + model.getId() + "', '"
                        + model.getUserName()+"','"
                        + model.getBirthday()+"','"
                        + model.getPhoneNumber()+"','"
                        + model.getQQ()+"','"
                        + model.getAddress()+"','"
                        + model.getCreateDate() + "');";
                db.execSQL(insertSql);
                cursor.close();
            Log.e("insertSql", "ok");
        }
        finally {

            db.close();
        }
    }

    /**
     * 查询
     * @param context 上下文
     * @param sql       SQl查询语句
     * @param fields  字段名集合
     * @return    查询结果集 List<String>类型
     */
    public static List<UserInfoDto> query(Context context, String sql) {
        Log.e("UserInfoDto", "取数据");
        List<UserInfoDto> dataList = new ArrayList<UserInfoDto>();
        Cursor cursor;//Id,UserName,Birthday,PhoneNumber,QQ,Address,CreateDate
        try {
            db = context.openOrCreateDatabase(DATABASE, MODE_PRIVATE, null);
            cursor = db.rawQuery(sql, null);
            if (cursor != null) {
                while (cursor.moveToNext()) {
                    UserInfoDto model =new UserInfoDto();
                    model.setId(cursor.getString(cursor.getColumnIndex("Id")));
                    model.setUserName(cursor.getString(cursor.getColumnIndex("UserName")));
                    model.setBirthday(cursor.getString(cursor.getColumnIndex("Birthday")));
                    model.setPhoneNumber(cursor.getString(cursor.getColumnIndex("PhoneNumber")));
                    model.setQQ(cursor.getString(cursor.getColumnIndex("QQ")));
                    model.setAddress(cursor.getString(cursor.getColumnIndex("Address")));
                    model.setCreateDate(cursor.getString(cursor.getColumnIndex("CreateDate")));
                    dataList.add(model);
                }
                cursor.close();//游标必须关闭
            }
        }catch(Exception e) {
            new AlertDialog.Builder(context).setIcon(android.R.drawable.ic_dialog_alert).setTitle("数据库连接错误：")
            .setMessage("数据访问异常。").show();
        } finally {
            db.close();
        }
        return dataList;
    }

    /**
     * 数据记录总条数
     * @param context 上下文
     * @param sql      SQL查询语句
     * @return          记录条数
     */
    public static int getCount(Context context, String sql) {

        int totalCounty = ;
        try {
            db = context.openOrCreateDatabase(DATABASE, MODE_PRIVATE, null);
            Cursor cursor = db.rawQuery(sql, null);
            cursor.moveToFirst();
            totalCounty = cursor.getInt();
            cursor.close();//游标必须关闭
        } catch (Exception e) {
            new AlertDialog.Builder(context)
                    .setIcon(android.R.drawable.ic_dialog_alert)
                    .setTitle("数据库连接错误：").setMessage("数据访问异常。").show();
        } finally {
            db.close();
        }
        return totalCounty;
    }
}

数据访问层

public class UserInfoDto {
    //Id,UserName,Birthday,PhoneNumber,QQ,Address,CreateDate
    private String Id;
    private String UserName;
    private String Birthday;
    private String PhoneNumber;
    private String QQ;
    private String Address;
    private String CreateDate;
    public String getId() {
        return Id;
    }
    public void setId(String id) {
        Id = id;
    }
    public String getUserName() {
        return UserName;
    }
    public void setUserName(String userName) {
        UserName = userName;
    }
    public String getBirthday() {
        return Birthday;
    }
    public void setBirthday(String birthday) {
        Birthday = birthday;
    }
    public String getPhoneNumber() {
        return PhoneNumber;
    }
    public void setPhoneNumber(String phoneNumber) {
        PhoneNumber = phoneNumber;
    }
    public String getQQ() {
        return QQ;
    }
    public void setQQ(String qQ) {
        QQ = qQ;
    }
    public String getAddress() {
        return Address;
    }
    public void setAddress(String address) {
        Address = address;
    }
    public String getCreateDate() {
        return CreateDate;
    }
    public void setCreateDate(String createDate) {
        CreateDate = createDate;
    }
}

实体层