Unity2D教程：配置SQLite，并在安卓运行（附带SQLite常用操作）

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教程总目录

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配置SQLite是我遇到的Gradle以外的最恶心的事情了。

环境： Unity2019版本，.NET2.0

电脑篇

• 导入两个dll文件，Mono.Data.Sqlite.dll以及SQLite3.dll，放到Asset/Plugins下面。

• Mono.Data.Sqlite.dll在Unity安装目录下面找一个，SQLite3.dll网上下一个

• 我有.Net 2.0版本的你们可以试试
  https://pan.baidu.com/s/10zfaiH_kY0NP5ub_WfH_fQ，提取码9ls3

• 代码内using一下

using Mono.Data.Sqlite;

• 至此应该可以正常使用了

安卓篇

• 在电脑配置的基础上，你需要额外两个单单适用于Android的文件：libsqlite3.so和System.Data.dll。
• System.Data.dll在Editor\Data\MonoBleedingEdge\lib\mono\2.0-api下面，libsqlite3.so网上下。
• 这两个文件上面的链接里面也有
• 然后你会发现Unity报错，说什么和另外一个同名了，所以你需要在Unity内对这两个文件进行配置：
  
  
• 还有一个就是比较重要的就是在Build Setting-Player-Other里面，写入权限改为SDCard，也就是文件写入权限。这样在创建数据库时，可以直接使用Directory.CreateDirectory创建目录。
  

常用操作

/* 
 *  Author : Jk_Chen
 */

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

public class SQL
{
    /// <summary>
    /// 单例模式
    /// </summary>
    private SQL() { }
    public static readonly SQL instance = new SQL();

    private SqliteConnection conn;

    //——————————————————————————————数据库——————————————————————————————//

    string path = Config.instance.databasePath;

    /// <summary>
    /// 创建数据库
    /// </summary>
    /// <param name="dbName">数据库的名字，不用加.db</param>
    public void CreatDatabase(string dbName)
    {
        dbName += ".db";
        Debug.Log(path + dbName);
        if (!Directory.Exists(path))
        {
            Debug.Log("Create Database at " + path);
            Directory.CreateDirectory(path);
        }
        if (!File.Exists(path + dbName))
        {
            SqliteConnection.CreateFile(path + dbName);
        }
    }

    /// <summary>
    /// 打开数据库
    /// </summary>
    /// <param name="dbName">数据库的名字，不用加.db</param>
    public void OpenDataBase(string dbName)
    {
        dbName += ".db";
        Debug.Log(path + dbName);
        string connectionString = @"Data Source = " + path + dbName;
        try
        {
            conn = new SqliteConnection(connectionString);
            conn.Open();
            Debug.Log("Connected");
        }
        catch (Exception e)
        {
            Debug.Log(e.ToString());
        }
    }

    /// <summary>
    /// 关闭数据库
    /// </summary>
    public void CloseDataBase()
    {
        if (conn != null)
        {
            conn.Close();
        }
        conn = null;
        Debug.Log("Disconnected");
    }

    /// <summary>
    /// 删除数据库
    /// </summary>
    /// <param name="dbName">数据库名字</param>
    /// <returns>删除成功返回1，否则返回0</returns>
    public int DeleteDataBase(string dbName)
    {
        dbName += ".db";
        if (System.IO.File.Exists(path + dbName))
        {
            System.IO.File.Delete(path + dbName);
            return 1;
        }
        return 0;
    }

    //——————————————————————————————基础操作——————————————————————————————//

    /// <summary>
    /// Log
    /// </summary>
    /// <param name="x"></param>
    public void Log(string x)
    {
        Debug.Log("SqliteLog: " + x);
    }

    /// <summary>
    /// 非查询操作
    /// </summary>
    /// <param name="sql"></param>
    /// <param name="parameters"></param>
    /// <returns>返回影响条数</returns>
    public int ExecuteNonQuery(string sql, params SqliteParameter[] parameters)
    {
        int res = -1;
        try
        {
            SqliteCommand comm = new SqliteCommand(sql, conn);
            if (parameters.Length > 0)
                comm.Parameters.AddRange(parameters);

            res = comm.ExecuteNonQuery();
            Log("change lines " + res);
        }
        catch (SqliteException ex)
        {
            Log(ex.Message);
        }
        return res;
    }

    /// <summary>
    /// 执行查询语句，返回第一行的第一列
    /// </summary>
    /// <param name="sql"></param>
    /// <returns></returns>
    public object ExecuteScalar(string sql, params SqliteParameter[] parameters)
    {
        object res = null;
        try
        {
            SqliteCommand comm = new SqliteCommand(sql, conn);
            if (parameters.Length > 0)
                comm.Parameters.AddRange(parameters);
            res = comm.ExecuteScalar();
            Log("Find" + res.ToString());
        }
        catch (SqliteException ex)
        {
            Log(ex.Message);
        }
        return res;
    }

    /// <summary>
    /// 执行查询语句，返回SqliteDataReader
    /// </summary>
    /// <param name="sql"></param>
    /// <returns></returns>
    public SqliteDataReader ExecuteReader(string sql, params SqliteParameter[] parameters)
    {
        SqliteDataReader res = null;
        try
        {
            SqliteCommand comm = new SqliteCommand(sql, conn);
            if (parameters.Length > 0)
                comm.Parameters.AddRange(parameters);
            res = comm.ExecuteReader();
        }
        catch (SqliteException ex)
        {
            Log(ex.Message);
        }
        return res;
    }

    /// <summary>
    /// 显示所有查询结果，包括表头
    /// </summary>
    /// <param name="sql"></param>
    public void ShowAllOfDataReader(string sql, params SqliteParameter[] parameters)
    {
        using (var sdr = ExecuteReader(sql,parameters))
        {
            string s = "";
            for (int i = 0; i < sdr.FieldCount; i++)
            {
                s += sdr.GetName(i) + " ";
            }
            s += '\n';
            while (sdr.Read())
            {
                for (int i = 0; i < sdr.FieldCount; i++)
                {
                    s += sdr[i] + " ";
                }
                s += '\n';
            }
            Log(s);
        }
    }

    //——————————————————————————————表相关——————————————————————————————//

    /// <summary>
    /// 通过列名和列类型创建表
    /// </summary>
    /// <param name="name">表的名称</param>
    /// <param name="col">列名</param>
    /// <param name="colType">列类型</param>
    /// <returns></returns>
    public int CreateTable(string tbName, string[] col, string[] colType)
    {
        if (col.Length != colType.Length)
        {
            throw new SqliteException("columns.Length != colType.Length");
        }
        string sql = "CREATE TABLE " + tbName + " (" + col[0] + " " + colType[0] + " PRIMARY KEY";
        for (int i = 1; i < col.Length; ++i)
        {
            sql += ", " + col[i] + " " + colType[i];
        }
        sql += ")";
        return ExecuteNonQuery(sql);
    }

    /// <summary>
    /// 删除表
    /// </summary>
    /// <param name="tbName"></param>
    /// <returns></returns>
    public int DropTable(string tbName)
    {
        string sql = "Drop table if exists " + tbName;
        return ExecuteNonQuery(sql);
    }

    /// <summary>
    /// 查看所有表的结构
    /// </summary>
    public void ShowTablesInfo()
    {
        string sql = "SELECT type as 类别,name as 名称,sql as 结构 FROM sqlite_master WHERE type='table'";
        ShowAllOfDataReader(sql);
    }

    /// <summary>
    /// 查看单张表的结构
    /// </summary>
    public void ShowTableInfo(string tbName)
    {
        string sql = string.Format("SELECT type as 类别,name as 名称,sql as 结构 FROM sqlite_master WHERE type='table' AND name='{0}'",tbName);
        ShowAllOfDataReader(sql);
    }

    /// <summary>
    /// 查看表是否存在
    /// </summary>
    public bool CheckTableExist(string tbName)
    {
        string sql = string.Format("SELECT count(*) FROM sqlite_master WHERE type='table' AND name='{0}'", tbName);
        int ct = int.Parse(ExecuteScalar(sql).ToString());
        return ct > 0;
    }

    public void ShowAllInTable(string tbName)
    {
        string sql = "Select * From " + tbName;
        ShowAllOfDataReader(sql);
    }

    /// <summary>
    /// CSharp类型转化为SQLite类别
    /// </summary>
    /// <param name="type">c#中的类别</param>
    /// <returns>SQLite中对应的类别</returns>
    string CSharpToSQLite(Type type)
    {
        string result = "Text";
        if (type == typeof(Int32))
        {
            result = "INT";
        }
        else if (type == typeof(String))
        {
            result = "Text";
        }
        else if (type == typeof(Single))
        {
            result = "Real";
        }
        else if (type == typeof(Boolean))
        {
            result = "INT";
        }
        else if (type == typeof(DateTime))
        {
            result = "DATETIME";
        }
        return result;
    }
}