Unity数据读取与存储_数据库SQLite

什么是SQLite

1. SQLite是一款轻型的数据库


2. SQLite的设计目标是嵌入式的


3. SQLite占用资源非常的低


4. SQLite能够支持Windows/Linux/Unix等等主流的操作系统

准备工作

安装SQLiteManager

在Unity中导入

Mono.Data.Sqlite.dll

sqlite3.dll

System.Data.dll

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Mono.Data.Sqlite;
using System;
using UnityEngine.UI;

public class StudentManager : MonoBehaviour {
    //输出文字
    public Text UItext;
    //数据库地址
    string path;
    //连接
    public SqliteConnection connection;
    //命令行
    public SqliteCommand command;
    //数据库操作类
    public SqliteDataReader reader;

	// Use this for initialization
	void Start () {
        //初始化地址
        path = "Data source = " + Application.dataPath + "/Student.sqlite";
        //创建连接
        connection = new SqliteConnection(path);
    }
    //OnGUI按钮
    private void OnGUI()
    {
        if (GUILayout.Button("           创建          "))
        {
            CreateDataBase();
            //关闭数据库
            Dispose();
        }
        if (GUILayout.Button("           添加           "))
        {
            Dispose();
            AddStudent();
            //关闭数据库
            Dispose();
        }
        if (GUILayout.Button("           查询           "))
        {
            Dispose();
            UItext.text = SelectStudent();
            //关闭数据库
            Dispose();

        }

        if (GUILayout.Button("           查询 2          "))
        {
            Dispose();
            UItext.text = SelectStudent2();
            //关闭数据库
            Dispose();

        }
        if (GUILayout.Button("           修改           "))
        {
            Dispose();
            UpdateStudent();
            //关闭数据库
            Dispose();

        }
        if (GUILayout.Button("           删除           "))
        {
            DeleteStudent();
            Dispose();

        }

    }
    private void Dispose()
    {
        if (command != null)
        {
            command.Dispose();
            command = null;
        }
        if (reader != null)
        {
            reader.Close();
            reader = null;
        }
        connection.Close();

    }
    private void DeleteStudent()
    {

        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();
        //编辑命令_删除单数
        string commandtext0 = "Delete From Student where rowid%2 != 0";
        //commandtext0 = "Delete From Student ";
        command.CommandText = commandtext0;
        //执行命令
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;
    }

    private void UpdateStudent()
    {

        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();
        //编辑命令_修改年龄
        string commandtext0 = "Update Student set Sage = '18' where Sname = '杨文川' ";
        command.CommandText = commandtext0;
        //执行命令
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;

    }

    //
    //查询
    private string SelectStudent()
    {
        //创建返回对象
        string text = "";
        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();

        //编辑命令_名字
        string commandtext0 = "select  \"Sname\" ,\"Sid\"  ,\"Sage\" from Student";
        command.CommandText = commandtext0;
        //保存信息
        reader = command.ExecuteReader();
        //创建字典
        Dictionary dic = new Dictionary();
        for (int i = 0; i < 20; i++)
        {
            if (reader.Read())
            {
                print(reader.GetString(2));
                dic.Add("学生:"+(i+1).ToString()+"的id为"+reader.GetString(1).ToString(), reader.GetString(0));
            }
      

        }
        foreach(KeyValuePair item in dic)
        {
            text += item.Key;
            text += "name:" + item.Value +"\n";
        }
        //清除命令
        command.Dispose();
        command = null;
        //关闭SqliteDataReader
        reader.Close();
        reader = null;
       
        //返回字符串
        return text;
    }

    //查询2
    private string SelectStudent2()
    {
        //创建返回对象
        string text = "";
        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();
        //编辑命令
        string commandtext = "select * from student where Sage>=12 and Sage<18";
        command.CommandText = commandtext;
        //保存信息
        reader = command.ExecuteReader();
        for (int i = 0; i < 20; i++)
        {
            if (reader.Read())
            {
                for (int a = 0; a < reader.FieldCount; a++)
                {
                    text += reader.GetString(a);
                }
            }
        }
        //清除命令
        command.Dispose();
        command = null;
        //返回字符串

        return text;

    }

    //添加
    private void AddStudent()
    {
        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();
        //编辑命令
        string commandtext0 = "insert into student (Sid,Sname,Ssex, Sage, Sdept)values('171111-1','杨文博','男','16','vr')";
        command.CommandText = commandtext0;
        //无返回值
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;
      
        //创建命令行
        command = connection.CreateCommand();
        string commandtext1 = "insert into student (Sid,Sname,Ssex, Sage, Sdept)values('171111-2','李枭','男','16','vr')";
        command.CommandText = commandtext1;
        //无返回值
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;
      
        //创建命令行
        command = connection.CreateCommand();
        string commandtext2 = "insert into student (Sid,Sname,Ssex, Sage, Sdept)values('171111-3','袁喆','女','16','vr')";
        command.CommandText = commandtext2;
        //无返回值
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;

        //创建命令行
        command = connection.CreateCommand();
        string commandtext3 = "insert into student (Sid,Sname,Ssex, Sage, Sdept)values('171111-4','杨文川','男','16','vr')";
        command.CommandText = commandtext3;
        //无返回值
        command.ExecuteNonQuery();
        //清除命令
        command.Dispose();
        command = null;
    }

    //创建数据库，检查数据库是否存在
    void CreateDataBase()
    {
        //打开数据库
        connection.Open();
        //创建命令行
        command = connection.CreateCommand();
        //编辑命令
        string commandtext0 = "Select count(*) from sqlite_master where type = \'table\' and name = \'Student\'";
        command.CommandText = commandtext0;
        //保存获取信息
        reader = command.ExecuteReader();
        //设置是否存在表student
        bool isExit = false;
        //读取数据库
        while (reader.Read())
        {
            for (int i = 0; i < reader.FieldCount; i++)
            {
                if (reader.GetValue(i).ToString() != "0")
                {
                    isExit = true;
                    Debug.Log("已存在");
                }
            }
        }
        //清除命令
        command.Dispose();
        command = null;
        //关闭SqliteDataReader
        reader.Close();

        //如果不存在Student该表
        if (!isExit)
        {
            string commandtext1 = "Create Table Student(Sid text,Sname text,Ssex text, Sage text, Sdept text)";

            command = connection.CreateCommand();
            command.CommandText = commandtext1;
            //无返回值
            command.ExecuteNonQuery();
            command.Dispose();
            command = null;
            Debug.Log("创建完成");
        }

    }

	// Update is called once per frame
	void Update () {
		
	}
}