mariadb/libmysqld
Alexander Barkov 6ba83565f0 MDEV-20022 sql_mode="oracle" does not support TO_NUMBER() function
This patch implements an Oracle style function to_number()
with the following signatures:

- to_number(number_or_string_subject)
- to_number(string_subject, string_format)

The function is implemented in sql/item_numconvfunc.cc.

The function returns the DOUBLE data type for
all signatures and input data types.

The format parser understands the following components:

- Digits: 0, 9
- Hex digits: X
- Group separators: comma (,) and G
- Decimal delimiers: period (.) and D
- Approximate number signature: EEEE
- Currency/numeric flags: $ and B
- Currency signatures: C, L, U
- Sign signatures: S, MI, PR
- Special format signatures: V, TM, TM9, TME
- Format flag: FM

Note, the parser was implemented assuming that we'll also have the
oppostite function to_char() soon for numeric input.
So it parser all known components.
However, the function to_number() does not support:
- Formats V, TM, TM9, TME. to_number() returns NULL if the format
  string has these components.
  These componens are supported only by to_char() in Oracle.

Features not inclided into this patch:
- The ON CONVERSION ERROR clause
- The third parameter (nlsparam)
- Internationalized components: G, D, C, L, U.
These features will be implemented later, under terms of MDEV-36978.

Notable changes in the other files:

- item_func.h: adding Item_handled_func::Handler_double

- simple_parser.h: adding a number of *CONTAINER* templates
  They help to save on duplicate code when creating classes
  suitable for passing into parsing templates such as OPT, OR2C, OR3C, etc

- simple_parser.h: Adding parsing templates OR4C and OR5C

- simple_parser.h: Moving the template "OPT" towars the beginning of the file
  Rule parsing templates TOKEN, TokenChoice, AND2, OR2C, OR3C, OR4C, OR5C, LIST
  now provide a sub-class Opt, to parse its optional rule.

- simple_parser.h: Adding "explicit" to all "operator bool" definitions

- Renaming Parser_templates::TOKEN to Parser_templates::TokenParser

- Adding "explicit" to all "operator bool()" templates/classes,
  to avoid hidden implicit conversion (to int, void*, etc).

- Renaming the LIST template parameter ELEMENT to ELEMENT_PARSER,
  to make it clearer what it is for.

- Renaming the OPT template parameter RULE to RULE_PARSER,
  to make it clearer what it is for.
2025-08-08 12:39:58 +04:00
..
examples Fix remaining typos 2025-04-29 11:18:00 +10:00
client_settings.h Merge 10.1 into 10.2 2019-05-13 17:54:04 +03:00
CMakeLists.txt MDEV-20022 sql_mode="oracle" does not support TO_NUMBER() function 2025-08-08 12:39:58 +04:00
emb_qcache.cc cleanup: remove unconditional #ifdef's 2024-11-05 14:00:47 -08:00
emb_qcache.h MDEV-19275 Provide SQL service to plugins. 2020-08-14 21:04:25 +04:00
embedded_priv.h Fixed crash in connect.misc with embedded server 2024-02-27 14:55:47 +02:00
lib_sql.cc Fixed memory leaks in embedded server and mysqltest 2024-04-05 12:40:49 +02:00
libmysql.c Fix typos in C comments in miscellaneous files 2025-03-24 13:36:28 +11:00
libmysqld.c Fixed crash in connect.misc with embedded server 2024-02-27 14:55:47 +02:00
libmysqld.def merge with 5.3 2011-10-19 21:45:18 +02:00
libmysqld.rc query_id and my_xid -> ulonglong 2005-01-27 22:38:56 +01:00
resource.h query_id and my_xid -> ulonglong 2005-01-27 22:38:56 +01:00