如果大家对Unity中如何使用数据库还不是很了解那么请看我之前的这篇文章。Unity3D研究院之使用C＃语言建立本地数据库（二十三）本篇文章我们讨论如何在Unity中打开一个第三方数据库配合Android与编辑器进行同步开发。如下图所示，这个是我目前工程的结构，为了方便调试MOMO使用预定义标签将编辑器与Android平台区分开，方便编辑器与Android平台同时调试。
下图如果看的不清楚，点击图片可查看大图。 不仅在Unity编辑器中可以显示数据库读取的内容，直接编译在真机中也可以显示数据库读取的内容。
按照上图所示我们把第三方数据库放在Plugins->Android->assets中，切记必须放在这里，否无无效，然后是代码。这个第三方数据库是MOMO以前做测试一个号码归属地的时候制作的。所以数据库的内容还是比较大的，蛤蛤。
DbAccess.cs
using UnityEngine;
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 ()
{
}
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);
}
}
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.");
}
public SqliteDataReader ExecuteQuery (string sqlQuery)
{
dbCommand = dbConnection.CreateCommand ();
dbCommand.CommandText = sqlQuery;
reader = dbCommand.ExecuteReader ();
return reader;
}
public SqliteDataReader ReadFullTable (string tableName)
{
string query = "SELECT * FROM " + tableName;
return ExecuteQuery (query);
}
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);
}
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);
}
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];
}
Debug.Log(query);
return ExecuteQuery (query);
}
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);
}
public SqliteDataReader DeleteContents (string tableName)
{
string query = "DELETE FROM " + tableName;
return ExecuteQuery (query);
}
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);
}
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);
}
}
然后是Test.cs直接把它挂在摄像机对象身上。
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using Mono.Data.Sqlite;
public class Test :MonoBehaviour
{
//这三个是从数据库中取得的字段内容
string number = "null";
string city= "null";
string location = "null";
//处理在Android中显示中文
public GUISkin skin;
void Start ()
{
loadSQL ();
}
void loadSQL ()
{
//如果运行在编辑器中
#if UNITY_EDITOR
//通过路径找到第三方数据库
string appDBPath = Application.dataPath + "/Plugins/Android/assets/" + "location.db";
DbAccess db = new DbAccess("URI=file:" + appDBPath);
//如果运行在Android设备中
#elif UNITY_ANDROID
//将第三方数据库拷贝至Android可找到的地方
string appDBPath = Application.persistentDataPath + "/" + "location.db";
//如果已知路径没有地方放数据库，那么我们从Unity中拷贝
if(!File.Exists(appDBPath))
{
//用www先从Unity中下载到数据库
WWW loadDB = new WWW("jar:file://" + Application.dataPath + "!/assets/" + "location.db");
//拷贝至规定的地方
File.WriteAllBytes(appDBPath, loadDB.bytes);
}
//在这里重新得到db对象。
DbAccess db = new DbAccess("URI=file:" + appDBPath);
#endif
using (SqliteDataReader sqReader = db.SelectWhere("location_date",new string[]{"number","city","location"},new string[]{"_id"},new string[]{"="},new string[]{"25"}))
{
while (sqReader.Read())
{
//从数据库中找到对应字段
number = sqReader.GetString(sqReader.GetOrdinal("number"));
city = sqReader.GetString(sqReader.GetOrdinal("city"));
location = sqReader.GetString(sqReader.GetOrdinal("location")) ;
Debug.Log("number =" + number + " city =" + city + " location =" + location );
}
sqReader.Close();
}
db.CloseSqlConnection();
}
void OnGUI()
{
GUI.skin = skin;
GUILayout.Box("number =" + number);
GUILayout.Box("city =" + city);
GUILayout.Box("location =" + location);
}
}
上面代码中我们使用到了预定于标签，用于编译时区分游戏平台与版本。这么一来我们既可以在编辑器中操作数据库也可以在Android中操作数据库一举两得，主要是是Android平台比较特殊，不能从Unity的Assets资源路径中读取二进制文件。说道二进制文件，这里不仅读取第三方数据库还可以读取其它文件，二进制文件都可以读取，比如文本文件、图片、资源等等。需要注意的是你得把你的二进制文件放在Plugins->Android->assets中，然后根据下面的路径就可以在Android中读取。string Path = jar:file://” + Application.dataPath + “!/assets/” + “你的文件“;另外，使用这种方法读取地方放数据库后，是可以继续向数据库执行插入、删除、修改 、查询、等操作，用起来还是比较方便的。Unity预定义标签的种类还有很多，不仅可以区分平台还可以区分版本。
| UNITY_EDITOR | Define for calling Unity Editor scripts from your game code. |
| UNITY_STANDALONE_OSX | Platform define for compiling/executing code specifically for Mac OS (This includes Universal, PPC and Intel architectures). |
| UNITY_DASHBOARD_WIDGET | Platform define when creating code for Mac OS dashboard widgets. |
| UNITY_STANDALONE_WIN | Use this when you want to compile/execute code for Windows stand alone applications. |
| UNITY_WEBPLAYER | Platform define for web player content (this includes Windows and Mac Web player executables). |
| UNITY_WII | Platform define for compiling/executing code for the Wii console. |
| UNITY_IPHONE | Platform define for compiling/executing code for the iPhone platform. |
| UNITY_ANDROID | Platform define for the Android platform. |
| UNITY_PS3 | Platform define for running PlayStation 3 code. |
| UNITY_XBOX360 | Platform define for executing Xbox 360 code. |
| UNITY_NACL | Platform define when compiling code for Google native client (this will be set additionally to UNITY_WEBPLAYER). |
| UNITY_FLASH | Platform define when compiling code for Adobe Flash. |
Note: These defines were introduced at version 3.0.
Also you can compile code selectively depending on the version of the engine you are working on. Currently the supported ones are:
| UNITY_2_6 | Platform define for the major version of Unity 2.6. |
| UNITY_2_6_1 | Platform define for specific version 1 from the major release 2.6. |
| UNITY_3_0 | Platform define for the major version of Unity 3.0. |
| UNITY_3_0_0 | Platform define for the specific version 0 of Unity 3.0. |
| UNITY_3_1 | Platform define for major version of Unity 3.1. |
| UNITY_3_2 | Platform define for major version of Unity 3.2. |
| UNITY_3_3 | Platform define for major version of Unity 3.3. |
| UNITY_3_4 | Platform define for major version of Unity 3.4. |
| UNITY_3_5 | Platform define for major version of Unity 3.5. |
用法就不解释了，地球人都知道。
雨松MOMO希望和大家一起进步，加油～～～最后文本的源码下载：http://vdisk.weibo.com/s/ac3xI
雨松MOMO祝大家学习愉快，哇咔咔，晚安啦啦啦～～
