How to combine cin and database in c++

Cin in C can be combined with the database through a database interface library (such as MySQL Connector/C or ODBC). Specific steps include: installing the database interface library; establishing a database connection; creating a query statement; binding the cin input to the query parameters; executing the query; and obtaining the query results.

The combination of cin and database in C

Use cin in C to read user input from the command line. And database is used to store and manage data. To combine cin with a database, you need to use a database interface library (such as MySQL Connector/C or ODBC).

Using MySQL Connector/C

1. Install the MySQL Connector/C library.

2. Include necessary header files in your C code.

   <code class="cpp">#include <iostream>
   #include <mysqlx/xdevapi.h></code>

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3. Establish a database connection.

   <code class="cpp">mysqlx::Session session("host", "port", "user", "password", "database");</code>

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4. Create query statement.

   <code class="cpp">std::string query = "SELECT * FROM table_name WHERE column_name = ?";</code>

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5. Bind cin input to query parameters.

   <code class="cpp">mysqlx::PreparedStatement stmt = session.prepare(query);
   std::string input;
   std::cin >> input;
   stmt.bind("column_name", input);</code>

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6. Execute the query.

   <code class="cpp">mysqlx::Result res = stmt.execute();</code>

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7. Get query results.

   <code class="cpp">for (auto row : res.fetchAll()) {
       std::cout << row[0].get<std::string>() << std::endl;
   }</code>

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Using ODBC

1. Include the necessary ODBC header files.

   <code class="cpp">#include <iostream>
   #include <sql.h>
   #include <sqlext.h></code>

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2. Establish a database connection.

   <code class="cpp">SQLHENV henv;
   SQLHDBC hdbc;
   
   SQLAllocEnv(&henv);
   SQLAllocConnect(henv, &hdbc);
   SQLDriverConnect(hdbc, nullptr, "DSN", SQL_NTS, nullptr, 0, nullptr, SQL_DRIVER_NOPROMPT);</code>

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3. Create a SQL statement handle.

   <code class="cpp">SQLHSTMT hstmt;
   SQLAllocStmt(hdbc, &hstmt);</code>

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4. Set SQL statement.

   <code class="cpp">std::string sql = "SELECT * FROM table_name WHERE column_name = ?";
   SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 0, 0, nullptr, 0, nullptr);</code>

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5. Bind cin input to a SQL statement.

   <code class="cpp">std::string input;
   std::cin >> input;
   SQLSetParam(hstmt, 1, SQL_C_CHAR, input.c_str(), input.length(), nullptr);</code>

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6. Execute SQL statement.

   <code class="cpp">SQLExecute(hstmt);</code>

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7. Get query results.

   <code class="cpp">SQLBindCol(hstmt, 1, SQL_C_CHAR, nullptr, 0, nullptr);
   
   while (SQLFetch(hstmt) == SQL_SUCCESS) {
       char buffer[1024];
       SQLGetData(hstmt, 1, SQL_C_CHAR, buffer, sizeof(buffer), nullptr);
       std::cout << buffer << std::endl;
   }</code>

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