---
title: "CREATE TYPE"
url: "https://docs.yugabyte.com/stable/api/ysql/the-sql-language/statements/ddl_create_type/"
---

# CREATE TYPE

Use the CREATE TYPE statement to create a user-defined type in a database.

## Synopsis

Use the `CREATE TYPE` statement to create a user-defined type in a database. There are five types: composite, enumerated, range, base, and shell. Each has its own `CREATE TYPE` syntax.

## Syntax

- [![Grammar Icon](/icons/file-lines.svg)Grammar](#grammar-1)
- [![Diagram Icon](/icons/diagram.svg)Diagram](#diagram-1)

```output.ebnf
create_type ::= create_composite_type
                | create_enum_type
                | create_range_type
                | create_shell_type
                | create_base_type

create_composite_type ::= CREATE TYPE type_name AS ( 
                          [ composite_type_elem [ , ... ] ] )

create_enum_type ::= CREATE TYPE type_name AS ENUM ( 
                     [ name [ , ... ] ] )

create_range_type ::= CREATE TYPE type_name AS RANGE  ( SUBTYPE = 
                      subtype [ , range_type_option [ ... ] ] )

create_shell_type ::= CREATE TYPE type_name

create_base_type ::= CREATE TYPE type_name (  INPUT = input_function , 
                      OUTPUT = output_function 
                     [ , base_type_option [ ... ] ]  )

composite_type_elem ::= attribute_name data_type [ COLLATE collation ]

range_type_option ::= SUBTYPE_OPCLASS = subtype_operator_class
                      | COLLATION = collation
                      | CANONICAL = canonical_function
                      | SUBTYPE_DIFF = subtype_diff_function

base_type_option ::= RECEIVE = receive_function
                     | SEND = send_function
                     | TYPMOD_IN = type_modifier_input_function
                     | TYPMOD_OUT = type_modifier_output_function
                     | INTERNALLENGTH = { internallength | VARIABLE }
                     | PASSEDBYVALUE
                     | ALIGNMENT = alignment
                     | STORAGE = storage
                     | LIKE = like_type
                     | CATEGORY = category
                     | PREFERRED = { TRUE | FALSE }
                     | DEFAULT = default_type_value
                     | ELEMENT = element
                     | DELIMITER = delimiter
                     | COLLATABLE = { TRUE | FALSE }
```

#### create\_type

[create\_composite\_type](#create-composite-type)[create\_enum\_type](#create-enum-type)[create\_range\_type](#create-range-type)[create\_shell\_type](#create-shell-type)[create\_base\_type](#create-base-type)

#### create\_composite\_type

CREATETYPE[type\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#type-name)AS(,[composite\_type\_elem](#composite-type-elem))

#### create\_enum\_type

CREATETYPE[type\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#type-name)ASENUM(,[name](/stable/api/ysql/syntax_resources/grammar_diagrams#name))

#### create\_range\_type

CREATETYPE[type\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#type-name)ASRANGE(SUBTYPE=[subtype](/stable/api/ysql/syntax_resources/grammar_diagrams#subtype),[range\_type\_option](#range-type-option))

#### create\_shell\_type

CREATETYPE[type\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#type-name)

#### create\_base\_type

CREATETYPE[type\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#type-name)(INPUT=[input\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#input-function),OUTPUT=[output\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#output-function),[base\_type\_option](#base-type-option))

#### composite\_type\_elem

[attribute\_name](/stable/api/ysql/syntax_resources/grammar_diagrams#attribute-name)[data\_type](/stable/api/ysql/syntax_resources/grammar_diagrams#data-type)COLLATE[collation](/stable/api/ysql/syntax_resources/grammar_diagrams#collation)

#### range\_type\_option

SUBTYPE\_OPCLASS=[subtype\_operator\_class](/stable/api/ysql/syntax_resources/grammar_diagrams#subtype-operator-class)COLLATION=[collation](/stable/api/ysql/syntax_resources/grammar_diagrams#collation)CANONICAL=[canonical\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#canonical-function)SUBTYPE\_DIFF=[subtype\_diff\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#subtype-diff-function)

#### base\_type\_option

RECEIVE=[receive\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#receive-function)SEND=[send\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#send-function)TYPMOD\_IN=[type\_modifier\_input\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#type-modifier-input-function)TYPMOD\_OUT=[type\_modifier\_output\_function](/stable/api/ysql/syntax_resources/grammar_diagrams#type-modifier-output-function)INTERNALLENGTH=[internallength](/stable/api/ysql/syntax_resources/grammar_diagrams#internallength)VARIABLEPASSEDBYVALUEALIGNMENT=[alignment](/stable/api/ysql/syntax_resources/grammar_diagrams#alignment)STORAGE=[storage](/stable/api/ysql/syntax_resources/grammar_diagrams#storage)LIKE=[like\_type](/stable/api/ysql/syntax_resources/grammar_diagrams#like-type)CATEGORY=[category](/stable/api/ysql/syntax_resources/grammar_diagrams#category)PREFERRED=TRUEFALSEDEFAULT=[default\_type\_value](/stable/api/ysql/syntax_resources/grammar_diagrams#default-type-value)ELEMENT=[element](/stable/api/ysql/syntax_resources/grammar_diagrams#element)DELIMITER=[delimiter](/stable/api/ysql/syntax_resources/grammar_diagrams#delimiter)COLLATABLE=TRUEFALSE

## Semantics

The order of options in creating range types and base types does not matter. Even the mandatory options `SUBTYPE`, `INPUT`, and `OUTPUT` may appear in any order.

### *create\_composite\_type*

### *create\_enum\_type*

### *create\_range\_type*

### *create\_base\_type*

### *create\_shell\_type*

### *composite\_type\_elem*

### *range\_type\_option*

### *base\_type\_option*

- `type_name` specifies the name of this user-defined type.
- `attribute_name` specifies the name of an attribute for this composite type.
- `data_type` specifies the type of an attribute for this composite type.
- `collation` specifies the collation to use for this type. In case this is a composite type, the attribute data type must be collatable. In case this is a range type, the subtype must be collatable.
- `label` specifies a quoted label to be a value of this enumerated type.
- `subtype` specifies the type to use for this range type.
- `subtype_operator_class` specifies the operator class to use for the subtype of this range type.
- `canonical_function` specifies the canonical function used when converting range values of this range type to a canonical form.
- `subtype_diff_function` specifies the subtype difference function used to take the difference between two range values of this range type.
- `input_function` specifies the function that converts this type's external textual representation to internal representation.
- `output_function` specifies the function that converts this type's internal representation to external textual representation.
- `receive_function` specifies the function that converts this type's external binary representation to internal representation.
- `send_function` specifies the function that converts this type's internal representation to external binary representation.
- `type_modifier_input_function` specifies the function that converts this type modifier's external textual representation to internal integer typmod value or throws an error.
- `type_modifier_output_function` specifies the function that converts this type modifier's internal integer typmod value to external representation.
- `internallength` specifies the size in bytes of this type.
- `alignment` specifies the storage alignment of this type.
- `storage` specifies the storage strategy of this type. This type must be variable length.
- `like_type` specifies the type to copy over the `INTERNALLENGTH`, `PASSEDBYVALUE`, `ALIGNMENT`, and `STORAGE` values from.
- `category` specifies the category code for this type.
- `PREFERRED` specifies whether this type is preferred for implicit casts in the same category.
- `default` specifies the default value of this type.
- `element` Implies that the type being created is an array; this specifies the type of the array elements.
- `delimiter` specifies the character used to separate array elements in the external textual representation of values of this type.
- `COLLATABLE` specifies whether collation information may be passed to operations that use this type.

## Examples

Composite type

```plpgsql
yugabyte=# CREATE TYPE feature_struct AS (id INTEGER, name TEXT);
yugabyte=# CREATE TABLE feature_tab_struct (feature_col feature_struct);
```

Enumerated type

```plpgsql
yugabyte=# CREATE TYPE feature_enum AS ENUM ('one', 'two', 'three');
yugabyte=# CREATE TABLE feature_tab_enum (feature_col feature_enum);
```

Range type

```plpgsql
yugabyte=# CREATE TYPE feature_range AS RANGE (subtype=INTEGER);
yugabyte=# CREATE TABLE feature_tab_range (feature_col feature_range);
```

Base type

```plpgsql
yugabyte=# CREATE TYPE int4_type;
yugabyte=# CREATE FUNCTION int4_type_in(cstring) RETURNS int4_type
               LANGUAGE internal IMMUTABLE STRICT PARALLEL SAFE AS 'int4in';
yugabyte=# CREATE FUNCTION int4_type_out(int4_type) RETURNS cstring
               LANGUAGE internal IMMUTABLE STRICT PARALLEL SAFE AS 'int4out';
yugabyte=# CREATE TYPE int4_type (
               INPUT = int4_type_in,
               OUTPUT = int4_type_out,
               LIKE = int4
           );
yugabyte=# CREATE TABLE int4_table (t int4_type);
```

Shell type

```plpgsql
yugabyte=# CREATE TYPE shell_type;
```

## See also

- [ALTER TYPE](/stable/api/ysql/the-sql-language/statements/ddl_alter_type "ALTER TYPE")
- [DROP TYPE](/stable/api/ysql/the-sql-language/statements/ddl_drop_type "DROP TYPE")