Backport test utility functions

The resultset processing functions are helpful in writing tests that
process resultsets.

maxscale-system-test/mariadb_func.cpp

@@ -515,6 +515,36 @@ int find_field(MYSQL* conn, const char* sql, const char* field_name, char* value
     return ret;
 }
 
+Result get_result(MYSQL* conn, std::string sql)
+{
+    Result rval;
+    MYSQL_RES* res;
+
+    if (mysql_query(conn, sql.c_str()) == 0 && (res = mysql_store_result(conn)))
+    {
+        MYSQL_ROW row = mysql_fetch_row(res);
+
+        while (row)
+        {
+            rval.emplace_back(&row[0], &row[mysql_num_fields(res)]);
+            row = mysql_fetch_row(res);
+        }
+        mysql_free_result(res);
+    }
+    else
+    {
+        printf("Error: Query failed: %s\n", mysql_error(conn));
+    }
+
+    return rval;
+}
+
+Row get_row(MYSQL* conn, std::string sql)
+{
+    Result res = get_result(conn, sql);
+    return res.empty() ? Row{} : res[0];
+}
+
 int get_int_version(std::string version)
 {
     std::istringstream str(version);

maxscale-system-test/mariadb_func.h

@@ -24,6 +24,10 @@
 #include <stdarg.h>
 #include <errno.h>
 #include <string>
+#include <vector>
+
+typedef std::vector<std::string> Row;
+typedef std::vector<Row> Result;
 
 /**
  * Opens connection to DB: wropper over mysql_real_connect
@@ -204,6 +208,26 @@ int get_conn_num(MYSQL* conn, std::string ip, std::string hostname, std::string
  */
 int find_field(MYSQL* conn, const char* sql, const char* field_name, char* value);
 
+/**
+ * Execute a query and return the first row
+ *
+ * @param conn The connection to use
+ * @param sql  The query to execute
+ *
+ * @return The first row as a list of strings
+ */
+Row get_row(MYSQL* conn, std::string sql);
+
+/**
+ * Execute a query and return the result
+ *
+ * @param conn The connection to use
+ * @param sql  The query to execute
+ *
+ * @return The result as a list of rows
+ */
+Result get_result(MYSQL* conn, std::string sql);
+
 int get_int_version(std::string version);
 
 #endif // MARIADB_FUNC_H