added mysql backend

backends/mysql/src/mysql_result_reader.cpp

@@ -0,0 +1,35 @@
+#include "mysql_result_reader.hpp"
+
+namespace matador::backends::mysql {
+
+mysql_result_reader::mysql_result_reader(MYSQL_RES *result, unsigned int column_count)
+: result_(result)
+, row_count_(mysql_num_rows(result_))
+, column_count_(column_count)
+{}
+
+mysql_result_reader::~mysql_result_reader()
+{
+  if (result_) {
+    mysql_free_result(result_);
+  }
+}
+
+size_t mysql_result_reader::column_count() const
+{
+  return column_count_;
+}
+
+const char *mysql_result_reader::column(size_t index) const
+{
+  return current_row_[index];
+}
+
+bool mysql_result_reader::fetch()
+{
+  current_row_ = mysql_fetch_row(result_);
+
+  return current_row_ != nullptr;
+}
+
+}