Unity Sqlite的使用与简单封装

本文主要是介绍Unity Sqlite的使用与简单封装，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

并不是要介绍网上一搜一大片的Sqlite在Unity中的用法，而是想介绍下不一样的封装。另外对Unity和C#中的反射也并不熟练，所以难免疏漏。

Unity中使用Sqlite

所需文件

Mono.Data.Sqlite.dll
Mono.Data.dll
Sqlite3.dll       （32位/64位）

前两个文件在 \Unity\Editor\Data\MonoBleedingEdge\lib\mono\2.0 这个目下可以找到

后一个文件Sqlite 可以在这儿下载 https://sourceforge.net/projects/sqlitebrowser/ 需要注意下载对应的32位或者64位

将上面的三个文件拷贝至文件夹 Asset\Plugins 下。如果是用在Android上，还需要一个 libsqlite3.so 文件，放在 Asset\Plugins\Android\ 下，文件可以在下面的链接的文章中下载到。http://blog.csdn.net/qinyuanpei/article/details/46812655#t1

不知道为啥编辑器没有自动添加引用，所以使用时记得添加下面的几个引用。

：unity`SqliteConnection' could not be found.
using Mono.Data.Sqlite; ：The type ornamespace name `Exception' could not be found.
using System;：The type ornamespace name `SqliteDataReader' could not be found.
using System.IO;

简单使用

如果只是想简单的用用，下面的代码是一个使用示例。

来源：http://answers.unity3d.com/questions/743400/database-sqlite-setup-for-unity.html

    string conn = "URI=file:" + Application.dataPath + "/PickAndPlaceDatabase.s3db"; //Path to database.SqliteConnection dbconn;dbconn =  new SqliteConnection(conn);dbconn.Open(); //Open connection to the database.SqliteCommand dbcmd = dbconn.CreateCommand();string sqlQuery = "SELECT value,name, randomSequence " + "FROM PlaceSequence";dbcmd.CommandText = sqlQuery;SqliteDataReader reader = dbcmd.ExecuteReader();while (reader.Read()){int value = reader.GetInt32(0);string name = reader.GetString(1);int rand = reader.GetInt32(2);Debug.Log( "value= "+value+"  name ="+name+"  random ="+  rand);}reader.Close();reader = null;dbcmd.Dispose();dbcmd = null;dbconn.Close();dbconn = null;}

封装 DbUtil (反射)

如何在Unity上使用用上Sqlite 在这里不做过多的讨论，因为上面的两个链接里已经有详细的描述了。这里讨论下另外的写法。

保存数据时，我并不希望每次保存数据时都去写一遍Sql，而是希望更简洁的操作。我不想去关心我是在操作那个类的数据类，里面有哪些字段等等的封装。

比如创建两张不同的表：

dbUtil.CreateTable(new Pen());
dbUtil.CreateTable(new Person());

插入一条记录：

dbUtil.Insert(new Pen() { Id = 1, name = "钢笔1", color = "red", size = 1.123 });

插入链表：

dbUtil.InsertList(personList);
dbUtil.InsertList(penList);

不需要再去关心是哪个类，实体类有哪些字段等，就保存到数据库了。以前做Android开发的时候有很多开源框架可以使用，比如 xUtils 等。在Unity这用Sqlite似乎需求比较少，所以自己动手写个简单点的。用反射似乎效率会比较低，反射虽然慢，但对我们来说足以够快了。况且数据库操作不都是放到另外的线程里去的么？

Column.cs

首先要完成上面的操作，重要的一点就是拼接Sql语句，那就要先拿到类的相关信息。Sqlite 支持四中类型，blob用的少，不管了。另外三个 int对应integer，string对应text，double对应real。代码如下：

namespace Liangddyy.Util
{/// <summary>/// 反射字段/// </summary>public class Column{//Column Valueprivate readonly MyProperty property;public string columnName;public Type columnType;public Column(Type ColumnType, string ColumnName, object value){this.columnType = ColumnType;this.columnName = ColumnName;if (ColumnType == typeof(string)){string v = Convert.ToString(value);property = new MyProperty<string>();((MyProperty<string>) property).SetValue(v);}else if (ColumnType == typeof(double)){double v = Convert.ToDouble(value);property = new MyProperty<double>();((MyProperty<double>) property).SetValue(v);}else if (ColumnType == typeof(int)){int v = Convert.ToInt32(value);property = new MyProperty<int>();((MyProperty<int>) property).SetValue(v);}}public string TableType{get{if (IsPrimaryKey)return "INTEGER PRIMARY KEY";return To_TableType(columnType);}}public bool IsPrimaryKey{// 转换小写get{return (columnName.ToLower().StartsWith("id") || columnName.ToLower().StartsWith("_id")) &&(columnType == typeof(int));}}public object ColumnValue{get{if (property == null) return null;if (columnType == typeof(double))return ((MyProperty<double>) property).GetValue();if (columnType == typeof(string))return ((MyProperty<string>) property).GetValue();if (columnType == typeof(int))return ((MyProperty<int>) property).GetValue();return null;}}public string To_TableType(Type type){if (type == typeof(double)) return ColType.REAL.ToString();if (type == typeof(int)) return ColType.INTEGER.ToString();if (type == typeof(string)) return ColType.TEXT.ToString();throw new Exception("Wrong Type");}}/// <summary>/// 枚举数据库Sqlite支持的几种类型/// </summary>public enum ColType{INTEGER,TEXT,REAL,BLOB}public class MyProperty{}public class MyProperty<T> : MyProperty{private readonly bool _isValue;private bool _changing;private T _value;public MyProperty(){
#if UNITY_FLASH_isValue = false;
#else_isValue = typeof(T).IsValueType;
#endif}public MyProperty(T value): this(){_value = value;}public bool IsOfType(Type t){return t == typeof(T);}public T GetValue(){return _value;}protected virtual bool IsValueDifferent(T value){return !_value.Equals(value);}private bool IsClassDifferent(T value){return !_value.Equals(value);}public virtual void SetValue(T value){if (_changing)return;_changing = true;bool changed;if (_isValue)changed = IsValueDifferent(value);elsechanged = ((value == null) && (_value != null)) ||((value != null) && (_value == null)) ||((_value != null) && IsClassDifferent(value));if (changed)_value = value;_changing = false;}}
}

DbUtil.cs

注意事项写在后面。

namespace Liangddyy.Util
{/// <summary>///     自己写的Sqlite封装类/// </summary>public class DbUtil{
#if UNITY_ANDROIDprivate static string path = "URI=file:" + Application.dataPath;
#endif
#if UNITY_IPHONEprivate static string path = "data source=" + Application.persistentDataPath;
#endif
#if UNITY_STANDALONE_WINprivate static readonly string path = "data source=" + Application.dataPath;
#endifprivate static readonly string dbName = "/test01.db";private static DbUtil dbUtil;private SqliteConnection dbConnection;private SqliteCommand dbCmd;private SqliteTransaction dbTransaction;private SqliteDataReader dbReader;public static DbUtil getInstance(){if (dbUtil == null)dbUtil = new DbUtil(path + dbName);return dbUtil;}private DbUtil(string connectionStr){try{dbConnection = new SqliteConnection(connectionStr);}catch (Exception e){Debug.LogError(e.Message);}}public SqliteDataReader ExecuteQuery(string queryString){dbCmd = dbConnection.CreateCommand();dbCmd.CommandText = queryString;dbReader = dbCmd.ExecuteReader();return dbReader;}public int ExecuteSql(string sqlStr){if (dbConnection.State == ConnectionState.Closed)dbConnection.Open();dbCmd = dbConnection.CreateCommand();dbCmd.CommandText = sqlStr;return dbCmd.ExecuteNonQuery();}private int ExecuteSql(SqliteCommand sqlCmd){return dbCmd.ExecuteNonQuery();}public void CreateTable<T>(T arg){this.ExecuteSql(GetCmdCreateTable(arg));}public void Insert<T>(T record){dbCmd = dbConnection.CreateCommand();this.ExecuteSql(GetCmdInsert<T>(record, dbCmd));}public void InsertList<T>(List<T> Records){dbTransaction = dbConnection.BeginTransaction();try{for (var i = 0; i < Records.Count; i++)Insert(Records[i]);dbTransaction.Commit();}catch (Exception){dbTransaction.Rollback();throw;}}public void InsertArray<T>(T[] Records){dbTransaction = dbConnection.BeginTransaction();try{for (var i = 0; i < Records.Length; i++)Insert(Records[i]);dbTransaction.Commit();}catch (Exception){dbTransaction.Rollback();throw;}}public void Update<T>(T arg){dbCmd = dbConnection.CreateCommand();this.ExecuteSql(GetCmdUpdate(arg, dbCmd));}/// <summary>///     关闭数据库连接 销毁连接/// </summary>public void CloseConnection(){//销毁Commandif (dbCmd != null)dbCmd.Cancel();dbCmd = null;//销毁Readerif (dbReader != null)dbReader.Close();dbReader = null;//销毁Connectionif (dbConnection != null)dbConnection.Close();dbConnection = null;}/// <summary>/// 更新的sql语句/// </summary>/// <typeparam name="T"></typeparam>/// <param name="arg">The argument.</param>/// <param name="cmd">The command.</param>/// <returns></returns>private SqliteCommand GetCmdUpdate<T>(T arg, SqliteCommand cmd){Type type = arg.GetType();var TableName = type.Name;Column[] Columns = GetColumnsByType(arg);if ((Columns == null) || (Columns.Length < 1)){Debug.LogError("Type is Wrong");return null;}Column key = null;Column[] normal = null;//Debug.Log("Now Insert:" + TableName);var RowLength = Columns.Length;normal = GetNormalColumn(Columns);cmd.CommandText = "UPDATE " + TableName + " SET " + normal[0].columnName + " = @" + normal[0].columnName;for (var i = 1; i < normal.Length; i++)cmd.CommandText += "," + normal[i].columnName + " = @" + normal[i].columnName;key = GetPrimaryColumn(Columns);cmd.CommandText += " WHERE " + key.columnName + " = @" + key.columnName + ";";for (var i = 0; i < RowLength; i++)cmd.Parameters.Add(new SqliteParameter("@" + Columns[i].columnName, Columns[i].ColumnValue));return cmd;}/// <summary>///     获取主键/// </summary>/// <param name="Columns">The columns.</param>/// <returns></returns>private Column GetPrimaryColumn(Column[] Columns){foreach (var item in Columns)if (item.IsPrimaryKey) return item;return null;}/// <summary>///     获取普通字段/// </summary>/// <param name="Columns">The columns.</param>/// <returns></returns>private Column[] GetNormalColumn(Column[] Columns){var tmp = new List<Column>();foreach (var item in Columns)if (!item.IsPrimaryKey)tmp.Add(item);return tmp.ToArray();}/// <summary>///     获取类的相关字段信息。/// </summary>/// <param name="arg">The argument.</param>/// <returns></returns>private Column[] GetColumnsByType<T>(T arg){FieldInfo[] fieldsThis =arg.GetType().GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);FieldInfo[] fieldsBase =arg.GetType().BaseType.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);FieldInfo[] fields = new FieldInfo[fieldsBase.Length + fieldsThis.Length];Array.Copy(fieldsBase, 0, fields, 0, fieldsBase.Length);Array.Copy(fieldsThis, 0, fields, fieldsBase.Length, fieldsThis.Length);int field_len = fields.Length;if ((fields == null) || (field_len < 1))return null;Column[] tableType = new Column[field_len];for (int i = 0; i < field_len; i++){String Cur_Name = fields[i].Name;Type Cur_Type = fields[i].FieldType;var Value = fields[i].GetValue(arg);tableType[i] = new Column(Cur_Type, Cur_Name, Value);}return tableType;}/// <summary>/// 建表Sql/// </summary>/// <typeparam name="T"></typeparam>/// <param name="arg">The argument.</param>/// <returns></returns>private string GetCmdCreateTable<T>(T arg){Type type = arg.GetType();string TableName = type.Name;Column[] columns = GetColumnsByType(arg);if ((columns == null) || (columns.Length < 1)){Debug.LogError("Type is Wrong");//todo 异常处理return null;}Debug.Log("NowCreate:" + TableName);string queryCreate = "CREATE TABLE IF NOT EXISTS " + TableName + "(" + columns[0].columnName + " " +columns[0].TableType;for (var i = 1; i < columns.Length; i++)queryCreate += ", " + columns[i].columnName + " " + columns[i].TableType;queryCreate += ");";return queryCreate;}/// <summary>/// 获取一条插入sql语句/// </summary>/// <typeparam name="T"></typeparam>/// <param name="record">The record.</param>/// <param name="cmd">The command.</param>/// <returns></returns>private SqliteCommand GetCmdInsert<T>(T record, SqliteCommand cmd){Type type = record.GetType();string TableName = type.Name;Column[] columns = GetColumnsByType(record);if ((columns == null) || (columns.Length < 1)){Debug.LogError("Type is Wrong");return null;}int RowLength = columns.Length;cmd.CommandText = "INSERT INTO " + TableName + "(" + columns[0].columnName;for (var i = 1; i < RowLength; i++)cmd.CommandText += "," + columns[i].columnName;cmd.CommandText += ") VALUES (@" + columns[0].columnName;for (var i = 1; i < RowLength; i++)cmd.CommandText += ",@" + columns[i].columnName;cmd.CommandText += ");";for (var i = 0; i < RowLength; i++)cmd.Parameters.Add(new SqliteParameter("@" + columns[i].columnName, columns[i].ColumnValue));return cmd;}}
}

注意事项

1 不同平台下数据库文件的路径不同，所以要判断一下。

#if UNITY_ANDROIDprivate static string path = "URI=file:" + Application.dataPath;
#endif
#if UNITY_IPHONEprivate static string path = "data source=" + Application.persistentDataPath;
#endif
#if UNITY_STANDALONE_WINprivate static readonly string path = "data source=" + Application.dataPath;
#endif

2 获取当前类的字段信息

GetType().GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);

获取父类的字段信息（BaseType）

arg.GetType().BaseType.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);

主要注意的是：

BindingFlags.Public 只能拿到public字段，而往往我们写实体类时，都是私有属性，然后Get/Set 所以必须加上BindingFlags.NonPublic 才能获取私有属性。

3 拼接Sql语句时切忌直接用String 拼接。

否则可能会有下面类似的报错：

SqliteException: SQLite error Insufficient parameters supplied to the command ...

正确写法类似于下面或者上面贴出的代码中拼接Sql部分。

command.CommandText = "INSERT INTO [User] (UserPK ,Name ,Password   ,Category ,ContactFK) VALUES ( @UserPK , @Name , @Password ,        @Category , @ContactFK)";
command.Parameters.Add(new SqliteParameter("@Name", "Has"));
...

优雅的使用

BaiduShurufa_2016-12-9_15-22-22

（截图是因为这里不必要的代码很长，这个代码又没有什么意思。）

建了三个类，为了区别，另外两个类属性一个是private，一个是public。（Get/Set隐藏了）。

随便绑定个脚本Start里放上下面的代码测试一下

DbUtil dbUtil = DbUtil.getInstance();dbUtil.CreateTable(new Person());//建表dbUtil.CreateTable(new Pen());dbUtil.Insert(new Pen() { Id = 1, name = "钢笔1", color = "red", size = 1.123 });//插入dbUtil.Insert(new Person() { Id = 1, Name = "liangddyy", Email = "hehe" });List<Pen> penList = new List<Pen>();List<Person> personList = new List<Person>();for (int i = 5; i < 20; i++){Pen pen = new Pen() {Id = i, name = "钢笔1", color = "red", size = 1.123};Person person = new Person() {Id = i, Name = "liang", Email = "你好"};personList.Add(person);penList.Add(pen);}dbUtil.InsertList(penList);//插入链表dbUtil.InsertList(personList);dbUtil.Update(new Person() { Id =  1, Name = "梁先生", Email = "这条记录被修改了哈哈" });dbUtil.CloseConnection();

打开 Sqlite数据库文件