unity之连接SQLite数据库_怎么确认unity连接上sqlite

创建数据库，可以选择SQLiteManager或者其他的sqlite工具，我创建了一个MyDataBase.sqlite，里面含有一个People表，内含2列，分别为name 和sex

为其添加2个字段

准备工作就做完了，下面就可以写代码了

打开unity, 把Mono.Data.Sqlite文件和System.Data.dll放到Assets目录下，在unity5.1的版本还要额外导入一个sqlite3.dll文件

与数据库有关的类

https://msdn.microsoft.com/zh-cn/library/system.data.sqlclient.sqlconnection(v=vs.110).aspx

using UnityEngine;
using System.Collections;
using Mono.Data.Sqlite;
using System.Data.SqlClient;
 
public class Mydata  {
     private SqliteConnection sqlConnection;
    private SqliteCommand sqlCommand;//数据库指令对象，也就是来执行SQLite语句的
    private SqliteDataReader sqlReader;//数据库读取对象，
    private string dataName = "Data Source = " + Application.dataPath + "/MyDataBase.sqlite";//你数据库所在的位置
 
    public Mydata() {
 
        sqlConnection = new SqliteConnection(dataName);
        sqlConnection.Open();
 
    
    }
 
 
    public  void OpenData(){
       sqlConnection = new SqliteConnection(dataName);
        sqlConnection.Open();
    
    }
 
    public void QueryAll(){
        OpenData();
        sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "SELECT * FROM People;";
        sqlCommand.ExecuteNonQuery();//执行语句
        sqlReader = sqlCommand.ExecuteReader();//读取
        ShowData();
        Close();
       
    
    }
 
    public void QueryOne() {
        OpenData();
        //查询name列，可能有多个值
        sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "Select  name from People;";
        sqlCommand.ExecuteNonQuery();
        sqlReader = sqlCommand.ExecuteReader();
        ShowData();
        Close();
        Debug.Log("**********************************");
 
    
    
    }
 
    public void QuerySpecalData() { 
    //查询满足条件的一个值
        OpenData();
        sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "select sex from People where name = 'cb';";
        sqlCommand.ExecuteNonQuery();
        sqlReader = sqlCommand.ExecuteReader();
        sqlReader.Read();
        Debug.Log(  sqlReader.GetValue(0));
        Close();
        Debug.Log("**********************************");
      
    
    
    }
 
 
    //插入
    public void InsertData() {
        OpenData();
        //Reader如果不管，就执行不了新的读取操作
        sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "insert into People values('bb','m');";
    
         int n =  sqlCommand.ExecuteNonQuery();
        Debug.Log(n);
    
        //一个SqliteCommand只能执行一条语句，如果想要在次执行，必须重新创建
        sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "select name  from People where sex = m;";
        sqlCommand.ExecuteNonQuery();
        sqlReader = sqlCommand.ExecuteReader();
        sqlReader.Read();
        Debug.Log(sqlReader.GetValue(0));
        Close();
        Debug.Log("**********************************");
 
    
    
    }
 
 
   public  void updateData() {
       OpenData();
       sqlCommand = sqlConnection.CreateCommand();
        sqlCommand.CommandText = "update people  set name = 'mm' where name = 'bb';";
       int n = sqlCommand.ExecuteNonQuery();
       Debug.Log(n);
       sqlCommand = sqlConnection.CreateCommand();
       sqlCommand.CommandText = "select  name from People;";
       sqlCommand.ExecuteNonQuery();
       sqlReader = sqlCommand.ExecuteReader();
       ShowData();
       Close();
       Debug.Log("**********************************");
    
    }
 
   public void delectData() {
       OpenData();
       sqlCommand = sqlConnection.CreateCommand();
       sqlCommand.CommandText = "delete from People where name = 'wal';";
       sqlCommand.ExecuteNonQuery();
 
       sqlCommand = sqlConnection.CreateCommand();
       sqlCommand.CommandText = "select name from People;";
       sqlCommand.ExecuteNonQuery();
       sqlReader = sqlCommand.ExecuteReader();
      ShowData();
      Close();
      Debug.Log("**********************************");
   }
 
 
    public void ShowData() { 
    
    while(sqlReader.Read()){
        for (int i = 0; i < sqlReader.FieldCount; i++)
        {
            if (sqlReader.GetValue(i) == null)
            {
                Debug.Log("该列值为null");
            }
            else
            {
                Debug.Log(sqlReader.GetValue(i));
            }
        }
    
    
    }
    
    }
 
    public void Close() { 
    
    if(sqlReader!=null){
 
        sqlReader.Dispose();//释放所占用的资源
    }
        if(sqlCommand!=null){
            sqlCommand.Dispose();
        }
 
        if(sqlConnection!=null){
            sqlConnection.Close();//关闭数据库
        }
    
    }
 
	
}

using UnityEngine;
using System.Collections;
 
public class Test : MonoBehaviour {
 
    Mydata mydata;
	void Start () {
        mydata = new Mydata();
        mydata.QueryAll();
        mydata.QueryOne();
        mydata.QuerySpecalData();
        mydata.InsertData();
        mydata.updateData();
        mydata.delectData();
	}
	
 
	void Update () {
	
	}
}

1.sqliteReader,sqliteCommand用过一次必须要关，否则不能接受新的指令

2.sqlite不支持删除整列...
3.如果数据库的位置获取错误，可能出现找不到表的情况，先检查数据库里有没有这个表，再检查代码中获取数据库所在位置的地方是否正确