Drizzled Public API Documentation

select_result.h
1 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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4  * Copyright (C) 2008 Sun Microsystems, Inc.
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19 
20 
21 #pragma once
22 
23 #include <drizzled/current_session.h>
24 
25 namespace drizzled {
26 
28 protected:
29  Session *session;
30  Select_Lex_Unit *unit;
31 
32 public:
34  {
35  session= current_session;
36  }
37  virtual ~select_result() {}
38  virtual int prepare(List<Item> &,
39  Select_Lex_Unit *u)
40  {
41  unit= u;
42  return 0;
43  }
44  /*
45  Because of peculiarities of prepared statements protocol
46  we need to know number of columns in the result set (if
47  there is a result set) apart from sending columns metadata.
48  */
49  virtual uint32_t field_count(List<Item> &fields) const
50  { return fields.size(); }
51  virtual void send_fields(List<Item>&)=0;
52  virtual bool send_data(List<Item>&)=0;
53  virtual bool initialize_tables(Join*)
54  { return 0; }
55  virtual bool send_eof()=0;
56  virtual void abort() {}
57  void set_session(Session *session_arg) { session= session_arg; }
58  void begin_dataset() {}
59 
60  /*****************************************************************************
61  ** Functions to provide a interface to select results
62  *****************************************************************************/
63 
64  virtual void send_error(drizzled::error_t errcode, const char *err);
65 
66  /*
67  Cleanup instance of this class for next execution of a prepared
68  statement/stored procedure.
69  */
70  virtual void cleanup()
71  {
72  /* do nothing */
73  }
74 
75 };
76 
77 } /* namespace drizzled */
78