【Unity】sqlite数据库在Unity中的使用

导入

mono.data.sqlite.dll
System.data.dll
sqlite3.dll
到Assets/Plugins文件夹

【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