【Unity】sqlite数据库在Unity中的使用

【Windows电脑】

mono.data.sqlite.dll和System.data.dll在Unity\Editor\Data\MonoBleedingEdge\lib\mono\2.0

sqlite3.dll需要下载：https://www.sqlite.org/download.html

window电脑下载：Precompiled Binaries for Windows（注意32位和64位）

下载完之后打开压缩包将sqlite.dll导入到Assets/Plugins文件夹下

【Mac电脑】

mono.data.sqlite.dll和System.data.dll在/Applications/Unity/Unity.app（右键显示包内容）/Contents/MonoBleedingEdge/lib/mono

sqlite3.dll需要下载：https://www.sqlite.org/download.html

Mac电脑下载：Precompiled Binaries for Mac OS X (x86)

下载完之后打开压缩包将sqlite.dll导入到Assets/Plugins文件夹下

简单的封装了一个SQLite的工具类，其中很多地方都没有完善，希望和大家共同学习和进步，同学们完善之后也希望贡献一下代码

using UnityEngine;  
using System.Collections;  
using Mono.Data.Sqlite;  
public class SQLite  ｛  
    public SqliteConnection connection;  
    private SqliteCommand command;  
    public SQLite(string path)  
    ｛  
        connection = new SqliteConnection (path);   // 创建SQLite对象的同时，创建SqliteConnection对象  
        connection.Open ();                         // 打开数据库链接  
        Command();  
    ｝  
    public SqliteCommand  Command()  
    ｛  
        command = connection.CreateCommand ();  
        return command;  
    ｝  
    // 【增加数据】  
    public SqliteDataReader InsertData(string table_name,string [] fieldNames,object [] values)  
    ｛  
        // 如果字段的个数，和数据的个数不相等，无法执行插入的语句，所以返回一个null  
        if (fieldNames.Length != values.Length) ｛  
            return null;  
        ｝  
        command.CommandText = "insert into "   table_name   "(";  
        for (int i = 0; i < fieldNames.Length; i ) ｛  
            command.CommandText  = fieldNames[i];  
            if (i < fieldNames.Length-1) ｛  
                command.CommandText  = ",";  
            ｝  
        ｝  
        command.CommandText  = ")"   "values (";  
        for (int i = 0; i < values.Length; i ) ｛  
            command.CommandText  = values [i];  
            if (i < values.Length - 1) ｛  
                command.CommandText  = ",";  
            ｝  
        ｝  
        command.CommandText  = ")";  
        Debug.Log (command.CommandText);  
        return command.ExecuteReader ();  
    ｝  
    // 【删除数据】  
    public SqliteDataReader DeleteData(string table_name,string [] conditions)  
    ｛  
        command.CommandText = "delete from "   table_name   " where "   conditions [0];  
        for (int i = 1; i < conditions.Length; i ) ｛  
            // or：表示或者  
            // and：表示并且  
            command.CommandText  = " or "  conditions[i];  
        ｝  
        return command.ExecuteReader ();  
    ｝  
    // 【修改数据】  
    public SqliteDataReader UpdateData(string table_name,string []values,string [] conditions)  
    ｛  
        command.CommandText = "update "   table_name   " set "   values [0];  
        for (int i = 1; i < values.Length; i ) ｛  
            command.CommandText  = ","   values [i];  
        ｝  
        command.CommandText  = " where "   conditions[0];  
        for (int i = 1; i < conditions.Length; i ) ｛  
            command.CommandText  = " or "   conditions [i];   
        ｝  
        return command.ExecuteReader ();  
    ｝  
    // 【查询数据】  
    public SqliteDataReader SelectData(string table_name,string [] fields)  
    ｛  
        command.CommandText = "select "   fields [0];  
        for (int i = 1; i < fields.Length; i ) ｛  
            command.CommandText  = ","   fields [i];  
        ｝  
        command.CommandText  = " from "   table_name;  
        return command.ExecuteReader ();  
    ｝  
    // 【查询整张表的数据】  
    public SqliteDataReader SelectFullTableData(string table_name)  
    ｛  
        command.CommandText = "select * from "   table_name;  
        return command.ExecuteReader ();  
    ｝  
    // 【关闭数据库】  
    public void CloseDataBase()  
    ｛  
        connection.Close ();  
        command.Cancel ();  
    ｝  
｝  

简单的使用一下封装的代码

using UnityEngine;  
using System.Collections;  
using Mono.Data.Sqlite;  
public class Test : MonoBehaviour ｛  
    // Use this for initialization  
    void Start () ｛  
        // 数据库文件的具体路径，有的是.sqlite/.db  
        string path = "data source ="   Application.streamingAssetsPath   "/"   "database0117.sqlite";  
        SQLite sql = new SQLite (path);  
        SqliteDataReader reader1 = sql.InsertData ("FirstTable", new string[]｛ "name", "score" ｝, new object[]｛"'Sivan'",99｝);  
        // 读取到的信息使用之后需要关闭  
        reader1.Close ();  
        SqliteDataReader reader2 = sql.DeleteData ("FirstTable", new string[]｛"name = 'LONG'" ｝);  
        reader2.Close ();  
        sql.CloseDataBase ();  
    ｝  
    // Update is called once per frame  
    void Update () ｛  
    ｝  
｝  

有几个需要注意的地方

1.封装的每一个语句的方法返回值都是SqliteDataReader（执行命令的方法有三个，封装的时候选择了返回内容最多的一个）

2.参数是字符串的时候，通过object数组添加数组元素的时候需要使用new object[]｛"'Sivan'",99｝

3.SqliteDataReader使用之后需要关闭！

4.数据库使用完之后必须关闭！

各平台下数据库存储的绝对路径

PC："data source="   Application.streamingAssetsPath  "/dataBase.db";

Mac："data source="  Application.streamingAssetsPath  "/dataBase.db";

Android："URI=file:" Application.persistentDataPath "/dataBase.db";

iOS："data source=" Application.persistentDataPath "/dataBase.db";

数据库文件可以是.db或者.sqlite