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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:07:14 +0000 |
commit | a175314c3e5827eb193872241446f2f8f5c9d33c (patch) | |
tree | cd3d60ca99ae00829c52a6ca79150a5b6e62528b /sql/select_handler.h | |
parent | Initial commit. (diff) | |
download | mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.tar.xz mariadb-10.5-9e4947182e0b875da38088fdd168e775f473b8ad.zip |
Adding upstream version 1:10.5.12.upstream/1%10.5.12upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sql/select_handler.h')
-rw-r--r-- | sql/select_handler.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sql/select_handler.h b/sql/select_handler.h new file mode 100644 index 00000000..5cc63231 --- /dev/null +++ b/sql/select_handler.h @@ -0,0 +1,86 @@ +/* + Copyright (c) 2018, 2019 MariaDB + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +#ifndef SELECT_HANDLER_INCLUDED +#define SELECT_HANDLER_INCLUDED + +#include "mariadb.h" +#include "sql_priv.h" + +/** + @class select_handler + + This interface class is to be used for execution of select queries + by foreign engines +*/ + +class select_handler +{ + public: + THD *thd; + handlerton *ht; + + SELECT_LEX *select; // Select to be excuted + + /* + Temporary table where all results should be stored in record[0] + The table has a field for every item from the select_lex::item_list. + The table is actually never filled. Only its record buffer is used. + */ + TABLE *table; + List<Item> result_columns; + + bool is_analyze; + + bool send_result_set_metadata(); + bool send_data(); + + select_handler(THD *thd_arg, handlerton *ht_arg); + + virtual ~select_handler(); + + int execute(); + + virtual bool prepare(); + + static TABLE *create_tmp_table(THD *thd, SELECT_LEX *sel); + +protected: + /* + Functions to scan the select result set. + All these returns 0 if ok, error code in case of error. + */ + + /* Initialize the process of producing rows of result set */ + virtual int init_scan() = 0; + + /* + Put the next produced row of the result set in table->record[0] + and return 0. Return HA_ERR_END_OF_FILE if there are no more rows, + return other error number in case of fatal error. + */ + virtual int next_row() = 0; + + /* Finish scanning */ + virtual int end_scan() = 0; + + /* Report errors */ + virtual void print_error(int error, myf errflag); + + bool send_eof(); +}; + +#endif /* SELECT_HANDLER_INCLUDED */ |