1/*
2 Copyright (c) 2014, 2015 SkySQL Ab & MariaDB Foundation
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; version 2 of the License.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */
16
17/*
18 This file implements the group_by_handler code. This interface
19 can be used by storage handlers that can intercept summary or GROUP
20 BY queries from MariaDB and itself return the result to the user or
21 upper level.
22*/
23
24#include "mariadb.h"
25#include "sql_priv.h"
26#include "sql_select.h"
27
28/*
29 Same return values as do_select();
30
31 @retval
32 0 if ok
33 @retval
34 1 if error is sent
35 @retval
36 -1 if error should be sent
37*/
38
39int Pushdown_query::execute(JOIN *join)
40{
41 int err;
42 ha_rows max_limit;
43 ha_rows *reset_limit= 0;
44 Item **reset_item= 0;
45 THD *thd= handler->thd;
46 TABLE *table= handler->table;
47 DBUG_ENTER("Pushdown_query::execute");
48
49 if ((err= handler->init_scan()))
50 goto error;
51
52 if (store_data_in_temp_table)
53 {
54 max_limit= join->tmp_table_param.end_write_records;
55 reset_limit= &join->unit->select_limit_cnt;
56 }
57 else
58 {
59 max_limit= join->unit->select_limit_cnt;
60 if (join->unit->fake_select_lex)
61 reset_item= &join->unit->fake_select_lex->select_limit;
62 }
63
64 while (!(err= handler->next_row()))
65 {
66 if (unlikely(thd->check_killed()))
67 {
68 thd->send_kill_message();
69 handler->end_scan();
70 DBUG_RETURN(-1);
71 }
72
73 /* Check if we can accept the row */
74 if (!having || having->val_bool())
75 {
76 if (store_data_in_temp_table)
77 {
78 if ((err= table->file->ha_write_tmp_row(table->record[0])))
79 {
80 bool is_duplicate;
81 if (likely(!table->file->is_fatal_error(err, HA_CHECK_DUP)))
82 continue; // Distinct elimination
83
84 if (create_internal_tmp_table_from_heap(thd, table,
85 join->tmp_table_param.
86 start_recinfo,
87 &join->tmp_table_param.
88 recinfo,
89 err, 1, &is_duplicate))
90 DBUG_RETURN(1);
91 if (is_duplicate)
92 continue;
93 }
94 }
95 else
96 {
97 if (join->do_send_rows)
98 {
99 int error;
100 /* result < 0 if row was not accepted and should not be counted */
101 if (unlikely((error= join->result->send_data(*join->fields))))
102 {
103 handler->end_scan();
104 DBUG_RETURN(error < 0 ? 0 : -1);
105 }
106 }
107 }
108
109 /* limit handling */
110 if (++join->send_records >= max_limit && join->do_send_rows)
111 {
112 if (!(join->select_options & OPTION_FOUND_ROWS))
113 break; // LIMIT reached
114 join->do_send_rows= 0; // Calculate FOUND_ROWS()
115 if (reset_limit)
116 *reset_limit= HA_POS_ERROR;
117 if (reset_item)
118 *reset_item= 0;
119 }
120 }
121 }
122 if (err != 0 && err != HA_ERR_END_OF_FILE)
123 goto error;
124
125 if ((err= handler->end_scan()))
126 goto error_2;
127 if (!store_data_in_temp_table && join->result->send_eof())
128 DBUG_RETURN(1); // Don't send error to client
129
130 DBUG_RETURN(0);
131
132error:
133 handler->end_scan();
134error_2:
135 handler->print_error(err, MYF(0));
136 DBUG_RETURN(-1); // Error not sent to client
137}
138
139
140void group_by_handler::print_error(int error, myf errflag)
141{
142 my_error(ER_GET_ERRNO, MYF(0), error, hton_name(ht)->str);
143}
144