UE4連接Mysql數據庫解決方案

第一步：請閱讀http://user.qzone.qq.com/378100977/blog/1430883016這位仁兄的鏈接，經過我的實際測試。這篇文章的代碼沒有問題。

第二步：這篇文章中未解決的問題：

程序可以編譯，但是鏈接找不到libmysql。解決的辦法就是將libmysql.dll放到Binaries中。

文章中使用了絕對路徑，比較LOW，估計作者也是稀裏糊塗，沒有深究。我們要相對路徑！！！ 做法：將文章中的PrivateIncludePaths改成PublicIncludePaths.爲什麼這麼改就可以了。可以看一下這兩個函數的註釋！有些朋友使用比較新的UE版本，可能會遇到RulesCompiler.GetModuleFileName(String)已過時的問題，解決辦法如下：

RulesAssembly RA;
FileReference CheckProjectFile;
UProjectInfo.TryGetProjectForTarget("工程名", out CheckProjectFile);
RA = RulesCompiler.CreateProjectRulesAssembly(CheckProjectFile);
FileReference FR = RA.GetModuleFileName(this.GetType().Name);
string ModulePath = Path.GetDirectoryName(FR.CanonicalName);

第三步：到這一步，很多新手花了很多時間，欣喜若狂。被UE折騰的扎耳撓思。終於編譯，調用沒有問題了。謝天謝天。那麼問題來了，這時候發現 讀取MYSQL中的中文數據後顯示的都是亂碼！！(如果你MySQL還沒連上，請不用往下看了。。)

亂碼問題：

中文亂碼無非就是編碼格式問題。MySQL現在默認都是UTF8編碼。不存在語言障礙。那爲什麼還是亂碼呢？當然，還是編碼問題！

解決亂碼問題：

在mysql_real_connect後，程序中設置編碼爲mysql_set_character_set(mysql, "utf8");【可能有人問，MySQL不是默認UTF8嗎？爲什麼還要設置？sorry,就得設置，否則無法正確顯示。修改MySQL配置文件也不行】。

將讀出的數據使用UTF8_TO_TCHAR（）函數轉碼。到此，中文亂碼問題解決。有了TCHAR，就擁有了FString.什麼都不怕了！

第四步：如何訪問MySQL數據庫，使用語句還是存儲過程？我的建議是，都搞搞。那個爽，用那個。存儲過程是MSSQL的TSQL集合，訪問數據庫效 率高，速度快！以前MySQL都沒有，終於良心發現，加上了。在目前的高版本中基本都支持。那麼問題來了，怎麼調用呢？請百度，大把的文章！

using System.IO;

namespace UnrealBuildTool.Rules
{
    public class MySQLSupport : ModuleRules
    {
        public MySQLSupport(ReadOnlyTargetRules Target) : base(Target)
        {
            PrivateDependencyModuleNames.AddRange(
                new string[] {
                "Core",
                "CoreUObject",
                "Engine",
                }
            );
            RulesAssembly RA;
            FileReference CheckProjectFile;
            UProjectInfo.TryGetProjectForTarget("VRHome", out CheckProjectFile);
            RA = RulesCompiler.CreateProjectRulesAssembly(CheckProjectFile);
            FileReference FR = RA.GetModuleFileName(this.GetType().Name);
            string ModulePath = Path.GetDirectoryName(FR.CanonicalName);

            //string ModulePath = Path.GetDirectoryName(RulesCompiler.GetModuleFilename(this.GetType().Name));         // gets the directory path of this module        
            string ThirdPartyPath = Path.GetFullPath(Path.Combine(ModulePath, "../../ThirdParty/"));                 // gets the ThirdParty folder directory path        
            string MySQLConnectorPath = ThirdPartyPath + "MySQL Connector.C6.1/";                                    // gets the MySQL Connector.C 6.1 folder path        
            string MySQLConnectorLibraryPath = MySQLConnectorPath + "lib/";                                          // gets the path of the lib folder        
            string MySQLConnectorIncludePath = MySQLConnectorPath + "include/";                                      // gets the path of the include folder        
            string MySQLConnectorImportLibraryName = Path.Combine(MySQLConnectorLibraryPath, "libmysql.lib");        // gets the file path and name of the libmysql.lib static import library        
            string MySQLConnectorDLLName = Path.Combine(MySQLConnectorLibraryPath, "libmysql.dll");                  // gets the file path and name of libmysql.dll        
            if (!File.Exists(MySQLConnectorImportLibraryName))                                                       // check to ensure the static import lib can be located, or else we'll be in trouble        
            {
                throw new BuildException(string.Format("{0} could not be found.", MySQLConnectorImportLibraryName));        // log an error message explaining what went wrong if not found        
            }
            if (!File.Exists(MySQLConnectorDLLName))                                                                 // check to make sure the dll can be located or else we'll be in trouble        
            {
                throw new BuildException(string.Format("{0} could not be found.", MySQLConnectorDLLName));           // log an error message explaining what went wrong if not found        
            }

            PublicIncludePaths.Add(MySQLConnectorIncludePath);                                                       // add the "include" folder to our dependencies. I've chosen PrivateIncludePaths since I hide the mysql headers from external code        
            PublicLibraryPaths.Add(MySQLConnectorLibraryPath);                                                       // add the "lib" folder to our dependencies        
            PublicAdditionalLibraries.Add(MySQLConnectorImportLibraryName);                                          // add libmysql.lib static import library as a dependency        
            PublicDelayLoadDLLs.Add(MySQLConnectorDLLName);                                                          // add libmysql.dll as a dll    
            RuntimeDependencies.Add(new RuntimeDependency("$(ProjectDir)/Binaries/Win64/libmysql.dll"));             // 自動添加libmysql.dll到指定的打包目錄中
        }
    }
}