获取SQL server数据库中表的列名，格式 C++实现

以下是获取 SQL Server 数据库中表的列名的 C++ 实现代码：

#include <windows.h>
#include <sql.h>
#include <sqlext.h>
#include <iostream>
 
using namespace std;
 
void show_error(unsigned int handle_type, const SQLHANDLE& handle)
{
    SQLCHAR sql_state[1024];
    SQLCHAR message[1024];
    SQLINTEGER sql_code;
    SQLSMALLINT length;
 
    SQLGetDiagRec(handle_type, handle, 1, sql_state, &sql_code, message, 1024, &length);
    cout << "SQL Error " << sql_code << " : " << message << endl;
}
 
int main()
{
    SQLHANDLE sql_env_handle = NULL;
    SQLHANDLE sql_conn_handle = NULL;
    SQLHANDLE sql_stmt_handle = NULL;
 
    SQLRETURN ret_code;
 
    SQLCHAR* db_name = (SQLCHAR*)"your_database_name";
    SQLCHAR* uid = (SQLCHAR*)"your_username";
    SQLCHAR* pwd = (SQLCHAR*)"your_password";
    SQLCHAR* query = (SQLCHAR*)"SELECT * FROM your_table_name";
 
    ret_code = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &sql_env_handle);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_ENV, sql_env_handle);
        return -1;
    }
 
    ret_code = SQLSetEnvAttr(sql_env_handle, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_ENV, sql_env_handle);
        return -1;
    }
 
    ret_code = SQLAllocHandle(SQL_HANDLE_DBC, sql_env_handle, &sql_conn_handle);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_ENV, sql_conn_handle);
        return -1;
    }
 
    ret_code = SQLConnect(sql_conn_handle, db_name, SQL_NTS, uid, SQL_NTS, pwd, SQL_NTS);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_DBC, sql_conn_handle);
        return -1;
    }
 
    ret_code = SQLAllocHandle(SQL_HANDLE_STMT, sql_conn_handle, &sql_stmt_handle);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_STMT, sql_stmt_handle);
        return -1;
    }
 
    ret_code = SQLExecDirect(sql_stmt_handle, query, SQL_NTS);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_STMT, sql_stmt_handle);
        return -1;
    }
 
    SQLSMALLINT column_count;
    SQLCHAR column_name[256];
    SQLSMALLINT column_name_length;
    SQLSMALLINT column_type;
    SQLULEN column_size;
    SQLSMALLINT column_decimal_digits;
    SQLSMALLINT column_nullable;
 
    ret_code = SQLNumResultCols(sql_stmt_handle, &column_count);
    if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
    {
        show_error(SQL_HANDLE_STMT, sql_stmt_handle);
        return -1;
    }
 
    cout << "Column count: " << column_count << endl;
 
    for (int i = 1; i <= column_count; i++)
    {
        ret_code = SQLDescribeCol(sql_stmt_handle, i, column_name, sizeof(column_name), &column_name_length, &column_type, &column_size, &column_decimal_digits, &column_nullable);
        if (ret_code != SQL_SUCCESS && ret_code != SQL_SUCCESS_WITH_INFO)
        {
            show_error(SQL_HANDLE_STMT, sql_stmt_handle);
            return -1;
        }
 
        cout << "Column " << i << ": " << column_name << endl;
    }
 
    SQLFreeHandle(SQL_HANDLE_STMT, sql_stmt_handle);
    SQLDisconnect(sql_conn_handle);
    SQLFreeHandle(SQL_HANDLE_DBC, sql_conn_handle);
    SQLFreeHandle(SQL_HANDLE_ENV, sql_env_handle);
 
    return 0;
}

在上面的代码中，我们使用 SQLDescribeCol 函数来获取表的列名。这个函数需要传入一个表的列索引，然后返回该列的一些信息，包括列名（column_name）。我们可以在循环中依次调用 SQLDescribeCol 函数来获取所有的列名。