utf8mb3 character set has these
Supports BMP characters only (no support for supplementary characters)
Requires a maximum of three bytes per multibyte character.
Applications that use UTF-8 data but require supplementary
character support should use
Section 10.9.1, “The utf8mb4 Character Set (4-Byte UTF-8 Unicode Encoding)”).
Exactly the same set of characters is available in
ucs2. That is,
they have the same
utf8 is an alias for
utf8mb3; the character limit is implicit,
rather than explicit in the name.
utf8mb3 character set will be replaced
utf8mb4 in some future MySQL version.
utf8 is currently an alias for
utf8mb3, at that point
utf8 will become a reference to
utf8mb4. To avoid ambiguity about the
utf8, consider specifying
utf8mb4 explicitly for character set
references instead of
utf8mb3 can be used in
SET clauses, and
COLLATE clauses, where
estonian_ci, and so forth. For example:
CREATE TABLE t (s1 CHAR(1) CHARACTER SET utf8mb3; SELECT * FROM t WHERE s1 COLLATE utf8mb3_general_ci = 'x'; DECLARE x VARCHAR(5) CHARACTER SET utf8mb3 COLLATE utf8mb3_danish_ci; SELECT CAST('a' AS CHAR CHARACTER SET utf8) COLLATE utf8_czech_ci;
MySQL immediately converts instances of
utf8mb3 in statements to
utf8, so in statements such as
CREATE TABLE or
FROM INFORMATION_SCHEMA.COLUMNS or
COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS, users
will see the name
utf8mb3 is also valid in contexts other than
CHARACTER SET clauses. For example:
SET NAMES 'utf8mb3'; /* and other SET statements that have similar effect */ SELECT _utf8mb3 'a';
For information about data type storage as it relates to multibyte character sets, see String Type Storage Requirements.