UE4 MySQL插件使用

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注意：该项目仅用于个人学习和demo使用，不可应用实际项目中，无论是安全性和性能都不符合需求

Update To 2.0

修复了一些bool返回结果错误的bug

优化了代码的可读性

更新了新的2.0方法 《SelectOnTableToMap》 取代 1.0方法《SelectOnTableData》

SelectOnTableToMap 采用了TMap<FString, FString>存取数据库查询返回结果集的一整行数据，采用TArray的结构保存

在虚幻中TArray，TMap无法作为参数和返回值，所以TArray，TMap会用Struct封装起来使用

Update To 3.0

修复了 2.0 里 《SelectOnTableToMap》只能读取数据库返回的结果集一行数据的bug

修复了虚幻引擎打包提示了类似".lib"的错误

更换了MySQL第三方库为第三方的MariaDB的库

插件支持UE5.1版的项目打包

[目前插件仅支持Win64或Win32打包，以后会支持到Linux] !!!更新个屁啊，写个WebSocket服务器在客户端和数据库之间做转发才是正道，这种用第三方库做插件的纯纯乐子!!!

1. 插件获取

GitHub URL = MySQL Plugin

2. 插件安装

1. 新建UE4项目，类型随意
2. 在项目根目录中新建文件夹Plugins
3. 将FH_MySQL复制到Plugins中
4. 重新打开UE4项目

3. 插件API

3.1 连接数据库

• 返回一个MySQL Connector

  /*
   * Connection == MySQL Object
   * @return *UFH_ConnectionObject == MySQL Connector
  */
  UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
  static UFH_ConnectionObject *ConnectToMySQL(FString Host, FString UserName, FString PassWord, FString DBName,
                                              int32 Port, FString &ConnectMessage);

3.2 获得连接状态

• 返回bool，正在连接返回true

  /*
   * ConnectionObject == MySQL Object
   * @return bool == ConnectionState
  */
  UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
  static bool GetConnectionState(UFH_ConnectionObject *ConnectionObject);

3.3 关闭数据库连接

• 肯定会关掉，默认返回true

  /*
   * ConnectionObject == MySQL Object
   * @return bool == ConnectionState
  */
  UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
  static bool CloseConnection(UFH_ConnectionObject *ConnectionObject);

3.4 增-删-改处理

• 实现增删改的处理，具体执行程序依据传入格式化SqlQuery

• Insert，Delete，Update

  /*
   * ConnectionObject == MySQL Object
   * @return bool == Insert, Update, Delete Data Is Succeed Or Failed
  */
  UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
  static bool ActionOnTableData(UFH_ConnectionObject *ConnectionObject, FString SqlQuery);

3.4.1 Insert Format SqlQuery

• 通用的 INSERT INTO TableName VALUES(InsertValues);格式化插入语句

  /*
   * TableName = DataBase TableName
   * InsertValues = MySQL Insert Values to Table
   * @return FString = MySQL Insert Query -> Insert
  */
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString InsertFormatSqlQuery(FString TableName, FString InsertValues);

3.4.2 Update Format SqlQuery

• 更新所有字段的值UPDATE TableName SET RowName = UpdateValue;格式化更新语句

  /*
   * TableName = DataBase TableName
   * RowName = Need Update Row
   * @return FString = MySQL Update Query -> Update
  */	
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString UpdateAllFormatSqlQuery(FString TableName, FString RowName, FString UpdateValue);

• 依据条件更新字段值UPDATE TableName SET UpdateRowName = UpdateValue WHERE WhereName = WhereValue;格式化更新语句

  /*
   * TableName = DataBase TableName
   * RowName = Need Update Row
   * WhereName = Update Where
   * WhereSymbol = Operator Or Symbol
   * WhereValue = Condition Name
   * UpdateValue = Need Update Date Value
   * @return FString = MySQL Update Query -> Update
  */	
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString UpdateByWhereFormatSqlQuery(FString TableName, FString RowName, FString WhereName, 
                                             FString WhereSymbol, FString WhereValue, FString UpdateValue);

3.4.3 Delete Format SqlQuery

• 删除整个表DELETE FROM TableName;格式化删除语句

  /*
   * TableName = DataBase TableName
   * @return FString = MySQL Delete Query -> Delete
  */
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString DeleteAllFormatSqlQuery(FString TableName);

• 依据条件删除整行数据DELETE FROM TableName WHERE WhereName=‘WhereValue’;格式化删除语句

  /*
   * TableName = DataBase TableName
   * WhereName = Update Where
   * WhereSymbol = Operator Or Symbol
   * WhereValue = Condition Name
   * @return FString = MySQL Delete Query -> Delete
  */
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString DeleteByWhereFormatSqlQuery(FString TableName, FString WhereName, FString WhereSymbol, 
                                             FString WhereValue);

3.5 查询语句处理

• 实现基本常用的查询语句：

  1. SELECT * FROM TableName;
  2. SELECT Columns1, Columns2, Country FROM TableName;
  3. 获得指定行的整行数据

• 处理查询语句的通用，具体执行程序依据传入格式化SqlQuery

• 函数公开生成并返回struct类型：

  • ResultRows整个表的数据
  • ResultRow整行的数据
  • RowValue整行内字段名的数据

3.5.1 Version1.0

/*
 * ConnectionObject == MySQL Object
 * @return bool == Select Data Is Succeed Or Failed
*/	
UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
static bool SelectOnTableData(UFH_ConnectionObject *ConnectionObject, FString SqlQuery, FQueryResultRows &ResultRows);

3.5.2 Version2.0

/*
 * 2.0 Select All Results In TArray<TMap> ResArray
 */
UFUNCTION(BlueprintCallable, Category="MySQL|Utils")
static bool SelectOnTableToMap(UFH_ConnectionObject* ConnectionObject, FString SqlQuery, FResArray& ResArray);

3.5.3 Select All Format SqlQuery

• 查询整个表的数据SELECT * FROM TableName;格式化查询语句

  /*
   * TableName = DataBase TableName
   * @return FString = MySQL Select Query -> Select
  */
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString SelectAllFormatSqlQuery(FString TableName);

3.5.4 Select Columns By Conditions

• 依据条件查询表内数据SELECT Columns1, Columns2, Country FROM TableName;格式化查询语句

  /*
   * TableName = DataBase TableName
   * @return FString = MySQL Select Query -> Select
  */	
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FString SelectByColumnsFormatSqlQuery(FString TableName, FString Columns);

3.5.5 Select Get RowValues By Index

• 指定表面和表内的行号，查询数据

  /*
   * TableName = DataBase TableName
   * @return TArray<FString> = Get All Rows -> In All Columns Values
  */		
  UFUNCTION(BlueprintPure, Category="MySQL|Utils")
  static FQueryResultRow GetRowByIndex(const FQueryResultRows &ResultRows, int32 RowIndex);