Development using MySQL and Ada language: How to implement data calculation functions

Development using MySQL and Ada language: How to implement data calculation functions

Overview:
MySQL is a popular relational database management system, and Ada language is a high-level programming language that is widely used In the development of systems with high requirements for high reliability and security. This article will introduce how to use MySQL and Ada language to develop data calculation functions, and provide corresponding code examples.

Step 1: MySQL database creation and connection
First, we need to create a database in MySQL and establish a connection with the Ada language. The following is a simple code example to connect to the MySQL database through Ada's SQL interface.

with SQL;
with Ada.Text_IO;

procedure MySQL_Connect is
   package SQL_IO is new Ada.Text_IO.Text_IO (File => SQL);
   
   -- 创建连接
   DB_Connection : SQL.Connection;
   Error_Message : SQL_IO.File_Type;

   -- 数据库连接信息
   Username : constant String := "your_username";
   Password : constant String := "your_password";
   Database : constant String := "your_database";
begin
   -- 连接到数据库
   SQL.Connect (DB_Connection, Username, Password, Database, Error_Message);
   
   -- 检查连接是否成功
   if DB_Connection.Is_Connected then
      SQL_IO.Put_Line ("连接成功!");
   else
      SQL_IO.Put_Line ("连接失败: " & Error_Message.all);
   end if;
   
   -- 关闭连接
   SQL.Disconnect (DB_Connection);
end MySQL_Connect;

Step 2: Perform data calculation
When connected to the database, we can perform data calculation by executing SQL queries. Below is a sample code that calculates the sum of a column in a table.

with SQL;
with Ada.Text_IO;

procedure Data_Calculation is
   package SQL_IO is new Ada.Text_IO.Text_IO (File => SQL);
   
   -- 创建连接
   DB_Connection : SQL.Connection;
   Error_Message : SQL_IO.File_Type;

   -- 数据库连接信息
   Username : constant String := "your_username";
   Password : constant String := "your_password";
   Database : constant String := "your_database";
   
   -- SQL查询语句
   Query : constant String :=
      "SELECT SUM(column_name) FROM table_name;";
   
   -- 查询结果
   Sum_Value : Integer;
begin
   -- 连接到数据库
   SQL.Connect (DB_Connection, Username, Password, Database, Error_Message);
   
   -- 检查连接是否成功
   if DB_Connection.Is_Connected then
      SQL_IO.Put_Line ("连接成功!");
   else
      SQL_IO.Put_Line ("连接失败: " & Error_Message.all);
      return;
   end if;
   
   -- 执行查询
   declare
      Result_Set : SQL.Result_Set;
   begin
      SQL.Execute (Result_Set, DB_Connection, Query, Error_Message);
      
      -- 获取查询结果
      SQL_IO.Get_Column (Result_Set, 1, Sum_Value);
      
      -- 输出查询结果
      SQL_IO.Put_Line ("总和: " & Sum_Value'Image);
      
      -- 关闭结果集
      SQL.Close (Result_Set);
   exception
      when others =>
         SQL_IO.Put_Line ("查询失败: " & Error_Message.all);
   end;
   
   -- 关闭连接
   SQL.Disconnect (DB_Connection);
end Data_Calculation;

Note:

• In the above code example, replace "your_username", "your_password" and "your_database" with your actual database information.
• In actual development, different data calculation functions can be achieved by modifying the query statement.

Summary:
This article introduces how to use MySQL and Ada language to develop data calculation functions, and provides corresponding code examples. By connecting to the MySQL database and executing SQL queries, we can achieve various data computing needs. I hope this article will be helpful to developers who use MySQL and Ada language for data calculations.

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