MFC + Windows 版 MySQL で UTF-8 な日本語を扱う

gistfile1.cpp

#include <my_global.h>
#include <mysql.h>

void TestMySQL()
{
	TRACE("MySQL client version: %s\n", mysql_get_client_info());

	MYSQL *conn = mysql_init(NULL);
	if (conn == NULL) {
		TRACE("Error %u: %s\n", mysql_errno(conn), mysql_error(conn));
	}

	if (mysql_real_connect(conn, "127.0.0.1", "user", "pass", "testdb", 0, NULL, 0) == NULL) {
		TRACE("Error %u: %s\n", mysql_errno(conn), mysql_error(conn));
	}

	mysql_query(conn, "set names utf8");

	// SELECT
	mysql_query(conn, "SELECT * FROM nihongo");
	MYSQL_RES *result = mysql_store_result(conn);

	int num_fields = mysql_num_fields(result);

	CString str = _T("");
	wchar_t bufUnicode[MAX_PATH];
	char bufUTF8[MAX_PATH];

	MYSQL_ROW row;
	while ((row = mysql_fetch_row(result))) {
		for (int i = 0; i < num_fields; i++) {
			if (row[i] == NULL) {
				TRACE("NULL ");
				continue;
			}

			int iLenUnicode = MultiByteToWideChar(CP_UTF8, 0, row[i], -1, NULL, 0);
			if (iLenUnicode <= sizeof(bufUnicode)/sizeof(bufUnicode[0])) {
				MultiByteToWideChar(CP_UTF8, 0, row[i], -1, bufUnicode, MAX_PATH);
				str += bufUnicode;
				str += _T(", ");
			}
		}

		TRACE("\n");
	}

	mysql_free_result(result);

	// INSERT
	CTime now = CTime::GetCurrentTime();
	CString s_now = now.Format(_T("%Y-%m-%d %H:%M:%S"));
	CString insert = _T("INSERT INTO nihongo VALUES('本日は") + s_now + _T("です')");
	wchar_t *p = insert.GetBuffer();

	int iLenUtf8 = WideCharToMultiByte(CP_UTF8, 0, p, -1, NULL, 0, NULL, NULL);
	if (iLenUtf8 <= sizeof(bufUTF8)) {
		WideCharToMultiByte(CP_UTF8, 0, p, -1, bufUTF8, sizeof(bufUTF8), NULL, NULL);
		mysql_query(conn, bufUTF8);
	}

	insert.ReleaseBuffer();

	mysql_close(conn);

	AfxMessageBox(str);
}