Unity Sqlite数据库操作

发表于2018-08-02
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Sqlite是一个轻量级数据库,在Unity中可以很方便的使用它。下面就来看下Sqlite数据库的操作。

首先在项目中添加两个动态链接库Mono.Data.Sqlite.dll和System.Data.dll

创建数据库管理脚本,该脚本用来直接操作数据库的操作,可以看作是对数据库操作的sql语句的封装。  
using UnityEngine;
using System.Data;
using System;
using System.Collections;
using Mono.Data.Sqlite;
public class DbAccess
{
    private SqliteConnection dbConnection;
    private SqliteCommand dbCommand;
    private SqliteDataReader reader;
    public DbAccess (string connectionString)
    {
        OpenDB (connectionString);
    }
    public DbAccess ()
    {
    }
    /// <summary>
    /// 打开数据库
    /// </summary>
    /// <param name="connectionString">Connection string.</param>
    public void OpenDB (string connectionString)
    {
        try
        {
            dbConnection = new SqliteConnection (connectionString);
            dbConnection.Open ();
            Debug.Log ("Connected to db");
        }
        catch(Exception e)
        {
            string temp1 = e.ToString();
            Debug.Log(temp1);
        }
    }
    /// <summary>
    /// 关闭数据库
    /// </summary>
    public void CloseSqlConnection ()
    {
        if (dbCommand != null) {
            dbCommand.Dispose ();
        }
        dbCommand = null;
        if (reader != null) {
            reader.Dispose ();
        }
        reader = null;
        if (dbConnection != null) {
            dbConnection.Close ();
        }
        dbConnection = null;
        Debug.Log ("Disconnected from db.");
    }
    /// <summary>
    /// 执行sql语句
    /// </summary>
    /// <returns>The query.</returns>
    /// <param name="sqlQuery">查询语句.</param>
    public SqliteDataReader ExecuteQuery (string sqlQuery)
    {
        Debug.Log ("sql="+sqlQuery);
        dbCommand = dbConnection.CreateCommand ();
        dbCommand.CommandText = sqlQuery;
        reader = dbCommand.ExecuteReader ();
        return reader;
    }
    /// <summary>
    /// 查询整个table的数据
    /// </summary>
    /// <returns>The full table.</returns>
    /// <param name="tableName">表名.</param>
    public SqliteDataReader ReadFullTable (string tableName)
    {
        string query = "SELECT * FROM " + tableName;
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 插入数据
    /// </summary>
    /// <returns>The into.</returns>
    /// <param name="tableName">表名</param>
    /// <param name="values">需要插入的字段内容,注意字符串需要添加单引号 如 ‘name’</param>
    public SqliteDataReader InsertInto (string tableName, string[] values)
    {
        string query = "INSERT INTO " + tableName + " VALUES (" + values[0];
        for (int i = 1; i < values.Length; ++i) {
            query += ", " + values[i];
        }
        query += ")";
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 更新table内容
    /// </summary>
    /// <returns>The into.</returns>
    /// <param name="tableName">Table 名称.</param>
    /// <param name="cols">需要更新的字段名称数组.</param>
    /// <param name="colsvalues">需要更新的字段对应的值.</param>
    /// <param name="selectkey">更新依据的字段.</param>
    /// <param name="selectvalue">更新依据字段对应的值</param>
    public SqliteDataReader UpdateInto (string tableName, string []cols,string []colsvalues,string selectkey,string selectvalue)
    {
        string query = "UPDATE "+tableName+" SET "+cols[0]+" = "+colsvalues[0];
        for (int i = 1; i < colsvalues.Length; ++i) {
            query += ", " +cols[i]+" ="+ colsvalues[i];
        }
        query += " WHERE "+selectkey+" = "+selectvalue+" ";
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 根据删除条件,删除对应的数据
    /// </summary>
    /// <param name="tableName">Table 名称.</param>
    /// <param name="cols">字段数组.</param>
    /// <param name="colsvalues">字段数组对应的值.</param>
    public SqliteDataReader Delete(string tableName,string []cols,string []colsvalues)
    {
        string query = "DELETE FROM "+tableName + " WHERE " +cols[0] +" = " + colsvalues[0];
        for (int i = 1; i < colsvalues.Length; ++i) {
            query += " or " +cols[i]+" = "+ colsvalues[i];
        }
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 插入数据,只插入部分字段的数据
    /// </summary>
    /// <returns>The into specific.</returns>
    /// <param name="tableName">Table 名称.</param>
    /// <param name="cols">需要插入的字段数组.</param>
    /// <param name="values">需要插入的字段数组对应的值.</param>
    public SqliteDataReader InsertIntoSpecific (string tableName, string[] cols, string[] values)
    {
        if (cols.Length != values.Length) {
            throw new SqliteException ("columns.Length != values.Length");
        }
        string query = "INSERT INTO " + tableName + "(" + cols[0];
        for (int i = 1; i < cols.Length; ++i) {
            query += ", " + cols[i];
        }
        query += ") VALUES (" + values[0];
        for (int i = 1; i < values.Length; ++i) {
            query += ", " + values[i];
        }
        query += ")";
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 根据表名,删除该表的全部数据
    /// </summary>
    /// <returns>The contents.</returns>
    /// <param name="tableName">Table name.</param>
    public SqliteDataReader DeleteContents (string tableName)
    {
        string query = "DELETE FROM " + tableName;
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 创建一个数据表
    /// </summary>
    /// <returns>The table.</returns>
    /// <param name="name">Name.</param>
    /// <param name="col">Col.</param>
    /// <param name="colType">Col type.</param>
    public SqliteDataReader CreateTable (string name, string[] col, string[] colType)
    {
        if (col.Length != colType.Length) {
            throw new SqliteException ("columns.Length != colType.Length");
        }
        string query = "CREATE TABLE " + name + " (" + col[0] + " " + colType[0];
        for (int i = 1; i < col.Length; ++i) {
            query += ", " + col[i] + " " + colType[i];
        }
        query += ")";
        return ExecuteQuery (query);
    }
    /// <summary>
    /// 根据条件筛选数据
    /// </summary>
    /// <returns>The where.</returns>
    /// <param name="tableName">Table name.</param>
    /// <param name="items">需要筛选的字段.</param>
    /// <param name="col">筛选条件的健.</param>
    /// <param name="operation">筛选符号,如 >,<,= </param>.</param>
    /// <param name="values">筛选条件的值.</param>
    public SqliteDataReader SelectWhere (string tableName, string[] items, string[] col, string[] operation, string[] values)
    {
        if (col.Length != operation.Length || operation.Length != values.Length) {
            throw new SqliteException ("col.Length != operation.Length != values.Length");
        }
        string query = "SELECT " + items[0];
        for (int i = 1; i < items.Length; ++i) {
            query += ", " + items[i];
        }
        query += " FROM " + tableName + " WHERE " + col[0] + operation[0] + "'" + values[0] + "' ";
        for (int i = 1; i < col.Length; ++i) {
            query += " AND " + col[i] + operation[i] + "'" + values[0] + "' ";
        }
        return ExecuteQuery (query);
    }
}

调用数据库方法,将该脚本挂载到场景中,完成对数据库管理脚本封装方法的调用。  
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Mono.Data.Sqlite;
public class SqliteTest1 : MonoBehaviour {
    string dbPath;
    string dbName;
    DbAccess db;
    // Use this for initialization
    void Start () {
        dbName="userInfo.db";
        dbPath=getPath ();
        if (!System.IO.File.Exists (dbPath)) {
            //创建数据库
            db = new DbAccess ("data source=" + dbPath);
            //创建数据库表,与字段
            SqliteDataReader reader= db.CreateTable ("user", new string[]{ "name", "age", "sex", "adress" }, new string[]{ "text", "integer", "text", "text" });
            if (reader != null)
                Debug.Log ("create tabel success");
            else
                Debug.LogError ("create tabel fail");
        } else db = new DbAccess ("data source=" + dbPath);
        //关闭对象
        //db.CloseSqlConnection();
    }
    string getPath(){
        string path=Application.dataPath+"/"+dbName;
        #if UNITY_EDITOR
        path=Application.streamingAssetsPath+"/"+dbName;
        if (!System.IO.Directory.Exists (path)){
//          System.IO.DirectoryInfo dir=new System.IO.DirectoryInfo(Application.streamingAssetsPath);
//          dir.Create();
            System.IO.Directory.CreateDirectory(Application.streamingAssetsPath);
        }
        #elif UNITY_ANDROID
        path=Application.persistentDataPath+"/"+dbName;
        #elif UNITY_IOS
        path=Application.persistentDataPath+"/"+dbName;
        #endif
        Debug.Log (Application.dataPath);
        Debug.Log (Application.persistentDataPath);
        Debug.Log (Application.temporaryCachePath);
        Debug.Log (path);
        return path;
    }
    void OnDestroy(){
        Debug.Log ("<color=#00ff00>close database</color>");
        //关闭对象
        db.CloseSqlConnection();
    }
    void InsertData(){
        db.InsertInto ("user", new string[]{ "'zhangsan'","11","'man'","'beijing'"});
        db.InsertInto ("user", new string[]{ "'lisi'","11","'woman'","'huoying'"});
    }
        void UpdateData(){
            db.UpdateInto ("user",new string[]{ "age", "sex"}, new string[]{ "82", "'woman'"  },"name","'zhangsan'");
        }
        void DeleteData(){
            db.Delete ("user",new string[]{ "age", "sex"}, new string[]{ "82", "'woman'"  });
    }
        void QueryData(){
            string query = "select * from user where name='zhangsan'";
            SqliteDataReader reader=db.ExecuteQuery (query);
            while(reader.Read()){
                Debug.Log ("name="+reader["name"]);
                Debug.Log ("age="+reader["age"]);
                Debug.Log ("sex="+reader["sex"]);
                Debug.Log ("adress="+reader["adress"]);
            }
        }
        void SelectData(){
        // "select (name,age,sex) from user where age > 20";
        SqliteDataReader reader= db.SelectWhere ("user",new string[]{"name","age","sex"},new string[]{"age"},new string[]{">"},new string[]{"20"});
        while(reader.Read()){
            Debug.Log ("name="+reader["name"]);
            Debug.Log ("age="+reader["age"]);
            Debug.Log ("sex="+reader["sex"]);
        }
        }
        void OnGUI() {
        if (GUI.Button (new Rect (10, 20, 100, 40), "insert data")) {
            InsertData ();
        } else if (GUI.Button (new Rect (10, 80, 100, 40), "delete data")) {
            DeleteData ();
        } else if (GUI.Button (new Rect (10, 120, 100, 40), "updata data")) {
            UpdateData ();
        } else if (GUI.Button (new Rect (10, 180, 100, 40), "query data")) {
            QueryData ();
        } else if (GUI.Button (new Rect (10, 250, 100, 40), "select data")) {
            SelectData ();
        }  
        else if (GUI.Button (new Rect (180, 20, 100, 40), "query all data")) {
        SqliteDataReader reader=    db.ReadFullTable("user");
            int count = 0;
        while(reader.Read()){
                count++;
//          Debug.Log ("name="+reader["name"]);
//          Debug.Log ("age="+reader["age"]);
//          Debug.Log ("sex="+reader["sex"]);
//          Debug.Log ("adress="+reader["adress"]);
            Debug.Log ("name=" + reader ["name"] + ",age=" + reader ["age"] + ",sex=" + reader ["sex"] + ",adress=" + reader ["adress"]);
        }
        Debug.Log ("count="+count);
        }  
    }
}
资源导包时报错:ArgumentException:TheAssemblySystem.ConfigurationisreferencedbySystem.Data(‘Assets/plugins/System.Data.dll’).Butthedllisnotallowedtobeincludedorcouldnotbefound.  

解决方法:在PlaySettings--othersetting中修改ApiCompatibilityLevel改成.NET2.0  
demo下载:http://download.csdn.net/detail/u011484013/9705852  
下载内容是一个unity资源包,拖到项目中之后,创建一个空场景,把SqliteTest1.cs挂载到相机上面,就可以运行测试。
来自:https://blog.csdn.net/u011484013/article/details/53521074

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