via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults key is of INTEGER or binary string types. The binary string types mainly refer to the following: • CHAR(N)CHARACTER SET BINARY • VARCHAR(N)CHARACTER SET BINARY • BINARY(N) • VARBINARY(N) • BIT(N) • The "ColumnType":"INT", "ColumnNullable":"false", "ColumnIsPk":"true" }, { "ColumnName":"LastName", "ColumnType":"CHAR", "ColumnLength":"20" }, { "ColumnName":"FirstName", "ColumnType":"VARCHAR", "ColumnLength":"30"

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+-- +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults key is of INTEGER or binary string types. The binary string types mainly refer to the following: • CHAR(N)CHARACTER SET BINARY • VARCHAR(N)CHARACTER SET BINARY • BINARY(N) • VARBINARY(N) • BIT(N) • The predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; 1724 explain select * from t where a < @a; +-- �→ -----------------------+------

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; 1599 explain select * from t where a < @a; +-- �→ -----------------------+------ +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters 96 Type Upper limit BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+-- +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+-- +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+-- +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

via the txn-entry-size-limit configuration item. 2.5.6 Limitations on data types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT Defaults predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+-- +------------+--------------+------+------+-------------------+-------+ | name | char(100) | NO | | NULL | | | store_type | char(100) | NO | | tikv,tiflash,tidb | | | reason | varchar(200) | YES | | NULL

and collations • To learn the details of the character sets and collations supported by TiDB, see Char- acter Set and Collation Overview. • To learn the MySQL compatibility of the GBK character set, see the txn-entry-size-limit configuration item. 2.7.6 Limitations on string types Type Upper limit CHAR 256 characters BINARY 256 characters VARBINARY 65535 characters VARCHAR 16383 characters TEXT 6 MB predicates which contain user variables cannot be pushed down create table t(id int primary key, a char); set @a = 1; explain select * from t where a < @a; +-- �→ -----------------------+----------+--

BIT BIT_XOR BLOB (R) BOOL BOOLEAN BOTH (R) BTREE BY (R) BYTE CASCADE (R) CASE (R) CAST CHANGE (R) CHAR (R) CHARACTER (R) CHARSET CHECK (R) CHECKSUM COALESCE COLLATE (R) COLLATION COLUMN (R) COLUMNS COMMENT 构建 如果 Column 的字符集和排序规则没有设置，那么表的字符集和排序规则就作为其默认值。 列的 Character Set 和 Collation 的语法如下： 1. col_name {CHAR | VARCHAR | TEXT} (col_length) 2. [CHARACTER SET charset_name] 3. [COLLATE collation_name] 支持 MySQL 所有的字符串类型，包括 CHAR、VARCHAR、BINARY、VARBINARY、BLOB、TEXT、ENUM 以 及 SET， 完整信息参考这篇文档。 日期时间类型 概述 类型定义 字符串类型 概述 类型定义 基本数据类型 - 105 - 本文档使用 书栈(BookStack.CN) 构建 语法： 1. [NATIONAL] CHAR[(M)] [CHARACTER SET charset_name]