test.rb

require File.dirname(__FILE__) + '/test_helper'

c = Mysql.real_connect('localhost','root')

c.send_query('select sleep(1)')
c.send_query('select sleep(1)')

with_sequence.diff

macbook-pros-computer:mysqlplus lourens$ git diff
diff --git a/ext/mysql.c b/ext/mysql.c
index b804723..89bdfb3 100644
--- a/ext/mysql.c
+++ b/ext/mysql.c
@@ -61,6 +61,7 @@ struct mysql {
     char connection;
     char query_with_result;
     char blocking;
+    char query_sent;
 };
 
 struct mysql_res {
@@ -278,6 +279,7 @@ static VALUE real_connect(int argc, VALUE* argv, VALUE klass)
     vio_fastsend( myp->handler.net.vio );
 
     myp->query_with_result = Qtrue;
+    myp->query_sent = Qfalse;
     rb_obj_call_init(obj, argc, argv);
 
     return obj;
@@ -797,14 +799,21 @@ static VALUE readable( int argc, VALUE* argv, VALUE obj )
 static VALUE send_query(VALUE obj, VALUE sql)
 {
     MYSQL* m = GetHandler(obj);
+    
+    /*free_old_query(m);*/
+
+    if( GetMysqlStruct(obj)->query_sent == Qtrue ){
+      rb_raise(eMysql, "Query out of sequence: Each call to Mysql#send_query requires a successive Mysql#get_result."); 
+    }
 
     Check_Type(sql, T_STRING);
     if (GetMysqlStruct(obj)->connection == Qfalse) {
         rb_raise(eMysql, "query: not connected");
     }
-         if (mysql_send_query(m, RSTRING_PTR(sql), RSTRING_LEN(sql)) != 0)
-             mysql_raise(m);
-         return Qnil;
+       if (mysql_send_query(m, RSTRING_PTR(sql), RSTRING_LEN(sql)) != 0)
+          mysql_raise(m);
+       GetMysqlStruct(obj)->query_sent = Qtrue;
+       return Qnil;
 }
 
 /* get_result */
@@ -814,12 +823,13 @@ static VALUE get_result(VALUE obj)
     if (GetMysqlStruct(obj)->connection == Qfalse) {
         rb_raise(eMysql, "query: not connected");
     }
-         if (mysql_read_query_result(m) != 0)
-             mysql_raise(m);
+       if (mysql_read_query_result(m) != 0)
+           mysql_raise(m);
     if (GetMysqlStruct(obj)->query_with_result == Qfalse)
        return obj;
     if (mysql_field_count(m) == 0)
              return Qnil;
+       GetMysqlStruct(obj)->query_sent = Qfalse;
     return store_result(obj);
 }