RTFM

CREATE (temporary) TABLE
You can also use the CREATE TABLE statement to create a temporary table. The CREATE TABLE syntax for temporary tables is more restrictive than for permanent tables. For this reason, and because of other characteristics, temporary tables are discussed in their own section.

Syntax
CREATE TABLE <# | ##>table-name (table-element [ , table-element ]... )

table-name ::= user-defined-name
table-element ::= column-definition | table-constraint-definition
column-definition ::= column-name data-type [ DEFAULT default-value-expression ] [ column-constraint [ column-constraint ]... [CASE (string) |
COLLATE collation-name ]

column-name ::= user-defined-name
data-type ::= data-type-name [ (precision [ , scale ] ) ]

precision ::= integer
scale ::= integer
default-value-expression ::= default-value-expression + default-value-expression

| default-value-expression - default-value-expression
| default-value-expression * default-value-expression
| default-value-expression / default-value-expression
| default-value-expression & default-value-expression
| default-value-expression | default-value-expression
| default-value-expression ^ default-value-expression
| ( default-value-expression )
| -default-value-expression
| +default-value-expression
| ~default-value-expression
| ?
| literal | scalar-function | { fn scalar-function }
| USER
| NULL


literal ::= 'string'
| number
| { d 'date-literal' }
| { t 'time-literal' }
| { ts 'timestamp-literal' }


scalar-function ::= see Scalar Functions
column-constraint ::= [ CONSTRAINT constraint-name ] col-constraint
constraint-name ::= user-defined-name
col-constraint ::= NOT NULL
| UNIQUE
| PRIMARY KEY
| REFERENCES table-name [ ( column-name ) ] [ referential-actions ]


table-constraint-definition ::= [ CONSTRAINT constraint-name ] table-constraint

table-constraint ::= UNIQUE ( column-name [ , column-name ]... )
| PRIMARY KEY ( column-name [ , column-name ]... )
REFERENCES table-name [ ( column-name [ , column-name ]... ) ]
[ referential-actions ]


referential-actions ::= referential-update-action [ referential-delete-action ]
| referential-delete-action [ referential-update-action ]

referential-update-action ::= ON UPDATE RESTRICT
referential-delete-action ::= ON DELETE CASCADE
| ON DELETE RESTRICT
collation-name ::= 'string' | user-defined-name

Remarks
A temporary table is used for intermediate results or working storage. Unlike in permanent tables, data in a temporary table is destroyed at some point during the SQL session or at the end of the SQL session. The data is not saved in the database.
Temporary tables are useful to narrow down intermediate results by continuing to operate on intermediate tables. Complex data operations are often easier if split into a sequence of simpler steps, which each step operating on the table result of a previous step. A temporary table is a base table. That is, the data it contains is its own. Contrast this with a view, which is an indirect representation of data in other tables.