Unity3D研究院之在Unity中打开第三方数据库配合Android开发（三十二）

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

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

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.

详细内容可以查看官网http://docs.unity3d.com/Documentation/Manual/PlatformDependentCompilation.html

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～～

本文固定链接: https://www.xuanyusong.com/archives/1454
转载请注明: 雨松MOMO 2012年07月05日于雨松MOMO程序研究院发表

最后编辑：2012-08-09

作者：雨松MOMO

专注移动互联网，Unity3D游戏开发

站内专栏 QQ交谈腾讯微博新浪微博

捐赠写博客不易，如果您想请我喝一杯星巴克的话？就进来看吧!