General syntax

This topic describes the general syntax of SQL statements, including constants, character sets, data types, SQL attributes, and storage attributes.

Constants

INT_VALUE: matches an integer constant, such as 123.
DECIMAL_VALUE: matches a fixed-point constant, such as 123.456.
STR_VALUE: matches a string constant, such as abc.
NULL: matches the NULL constant.
STORAGE_SIZE: matches a storage length constant. The default unit for an integer constant is bytes. For a string constant, you can specify the unit as M or G. For example, 1024 or '500M'.

const_value:
      INT_VALUE
    | DECIMAL_VALUE
    | STR_VALUE
    | NULL
    | STORAGE_SIZE

STORAGE_SIZE:
      INT_VALUE
    | 'INT_VALUE[M|G]'

Character sets

charset:
      default_charset
    | column_charset

default_charset:
    [DEFAULT] {CHARSET | CHARACTER SET} [=] {UTF8 | UTF8MB4 | BINARY}

column_charset:
    {CHARSET | CHARACTER SET} {UTF8 | UTF8MB4 | BINARY}

Collations

collate:
      default_collate
    | column_collate

default_collate:
    [DEFAULT] COLLATE [=] {UTF8MB4_GENERAL_CI | UTF8MB4_BIN | BINARY}

column_collate:
    COLLATE {UTF8MB4_GENERAL_CI | UTF8MB4_BIN | BINARY}

Data types

data_type:
      TINYINT[(precision)] [UNSIGNED] [ZEROFILL]
    | SMALLINT[(precision)] [UNSIGNED] [ZEROFILL]
    | MEDIUMINT[(precision)] [UNSIGNED] [ZEROFILL]
    | INT[(precision)] [UNSIGNED] [ZEROFILL]
    | INTEGER[(precision)] [UNSIGNED] [ZEROFILL]
    | BIGINT[(precision)] [UNSIGNED] [ZEROFILL]
    | FLOAT[(precision, scale)] [UNSIGNED] [ZEROFILL]
    | DOUBLE[(precision, scale)] [UNSIGNED] [ZEROFILL]
    | DECIMAL[(precision [, scale])] [UNSIGNED] [ZEROFILL]
    | NUMERIC[(precision [, scale])] [UNSIGNED] [ZEROFILL]
    | DATETIME[(scale)]
    | TIMESTAMP[(scale)]
    | DATE
    | TIME[(scale)]
    | YEAR
    | VARCHAR(length) column_charset column_collate
    | VARBINARY(length)
    | CHAR[(length)] column_charset column_collate
    | BINARY[(length)]
    | TINYTEXT column_charset column_collate
    | TINYLOB
    | TEXT[(length)] column_charset column_collate
    | BLOB[(length)]
    | MEDIUMTEXT column_charset column_collate
    | MEDIUMBLOB
    | LONGTEXT column_charset column_collate
    | LONGBLOB

precision | scale | length:
    INT_VALUE

SQL attributes

Object name

database_name | table_name | table_alias_name | column_name| column_alias_name  | partition_name | subpartition_name:
    STR_VALUE

index_name | view_name | object_name | constraint_name:
    STR_VALUE

outline_name | user_name:
    STR_VALUE

table_factor:
    [[database_name].] table_name

column_factor:
    [table_factor.] column_name

Expression

expression:
      const_value
    | column_factor
    | operator_expression
    | function_expression

Comment

comment:
    COMMENT 'comment_text'

comment_text:
    STR_VALUE

Storage attributes

BLOCK_SIZE: specifies the length of microblocks for object storage.
```
block_size:
BLOCK_SIZE [=] INT_VALUE
```

COMPRESSION: specifies the compression algorithm for object storage.

compression:
COMPRESSION [=] {NONE | LZ4_1.0 | LZ0_1.0 | SNAPPY_1.0}

PCTFREE: specifies the percentage of macroblocks reserved for object storage.
```
pctfree:
PCTFREE [=] INT_VALUE
```
TABLET_SIZE: specifies the minimum size of a tablet for a single task during parallel compaction.
```
tablet_size:
TABLET_SIZE [=] INT_VALUE
```

Constants​

Character sets​

Collations​

Data types​

SQL attributes​

Storage attributes​

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