I am creating a MySQL Table, and one of column's type is ENUM
.
I have several different ENUM
values. Some of them are two or more words, e.g. Hugo Boss.
Other ENUM
values have an apo开发者_如何学编程strophe in them, e.g. Men's, or other characters, e.g. &.
My question is two part:
- It is ok to have one or more spaces in an
ENUM
value (two words, or more)? - Are apostrophes, ampersands, and other such characters, allowed in
ENUM
values? And if they are, how would I go about placing them?
Seems so:
MySQL [files]> create temporary table t(foo ENUM('123', '1&2', '3\'4'));
Query OK, 0 rows affected (0.17 sec)
MySQL [files]> show create table t\G
*************************** 1. row ***************************
Table: t
Create Table: CREATE TEMPORARY TABLE `t` (
`foo` enum('123','1&2','3''4') COLLATE utf8_unicode_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
1 row in set (0.09 sec)
MySQL [files]> insert into t values (0), (1), (2), (3);
Query OK, 4 rows affected, 1 warning (0.12 sec)
Records: 4 Duplicates: 0 Warnings: 1
MySQL [files]> show warnings;
+---------+------+------------------------------------------+
| Level | Code | Message |
+---------+------+------------------------------------------+
| Warning | 1265 | Data truncated for column 'foo' at row 1 |
+---------+------+------------------------------------------+
1 row in set (0.11 sec)
MySQL [files]> select * from t;
+------+
| foo |
+------+
| |
| 123 |
| 1&2 |
| 3'4 |
+------+
4 rows in set (0.09 sec)
MySQL [files]>
Note: The warning means that I have used a value which was not allowed - I tried to insert 3, which is not defined as value for the ENUM
.
So it works perfectly - as with any other strings in MySQL. You only have to take care that you treat them correctly - either as hex values, or use mysql_real_escape_string()
or prepared statements. This provides for correct communication of "critical" values such as \\
, '
, "
etc.
For example, if I have a string which contains "3'4", and I want to define it as a part of an enum, I create the query by putting one of 0x332734
or '3\'4'
to the appropriate place. '3\'4'
is obtained as a result of mysql_real_escape_string("3'4")
in the used programming language.
NUL characters are not allowed as ENUM
components as they would be in data strings - the used string is terminated before, though.
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