Specifying Values (extended_value_spec)

Values are specified (extended_value_spec) using one of the keywords DEFAULT or STAMP or by specifying the values (value_spec: Literals, parameter specifications, key words and so on).

Structure

Syntax Syntax

<extended_value_spec> ::=
  DEFAULT
| STAMP
| <value_spec>

<value_spec> ::=
  <literal>
| <parameter_spec>
| NULL
| USER
| USERGROUP
| SYSDBA
| CURRENT_SCHEMA
| UID
| [<schema_name>.]<sequence_name>.NEXTVAL
| [<schema_name>.]<sequence_name>.CURRVAL
| <table_name>.CURRVAL
| DATE
| TIME
| TIMESTAMP
| UTCDATE
| TIMEZONe
| UTCDIFF
| TRUE
| FALSE
| TRANSACTION

End of the code.

Examples

SQL Tutorial, Number Generators for Tables

DEFAULT

DEFAULT identifies the default value for the column in a CREATE TABLE statement or ALTER TABLE statement. If one of these values is not defined, DEFAULT cannot be used to specify values.

The DEFAULT keyword can be used in the following SQL statements: INSERT statement, UPDATE statement. The DEFAULT keyword can be used in a DEFAULT predicate.

STAMP

The database system is capable of generating unique values. These comprise a series of consecutive numbers starting at X'000000000001'. The values are assigned in ascending order. There is no guarantee that a sequence of values is uninterrupted. The STAMP keyword returns the next value generated by the database system.

The STAMP keyword can be used in the following SQL statements (only on columns of data type CHAR(n) BYTE where n>=8): INSERT statement, UPDATE statement

If the user wants to find out the generated value before it is applied to a column, the following SQL statement must be used: NEXT STAMP Statement

<value_spec>

The following options are available for specifying values:

Specifying Values (value_spec)
<value_spec>	Explanation
<literal>	Literal
<parameter_spec>	Parameter specification
NULL	NULL Value
USER \| USERGROUP	Current user name or name of the user group to which the database user calling the SQL statement belongs. If the database user does not belong to a user group, the database user name is displayed.
SYSDBA	Database system administrator
CURRENT_SCHEMA	Current schema
UID	Identification of the current database user. This DEFAULT specification can only be specified with numeric data type and a minimum of 10 places before the decimal point.
[<schema_name>.]<sequence_name>.NEXTVAL \| [<schema_name>.]<sequence_name>.CURRVAL	NEXTVAL shows the next available value generated by the number generator (sequence [<schema_name>.]<sequence_name>). CURRVAL shows the value currently being used which was generated by the number generator (sequence [<schema_name>.]<sequence_name>). Further Explanations: CREATE SEQUENCE Statement (create_sequence_statement)
<table_name>.CURRVAL	Last value assigned in the current database session for the SERIAL column in the table table_name.
DATE \| TIME \| TIMESTAMP	Current date, time, time stamp.
UTCDATE	Current UTC time stamp (Greenwich Mean Time)
TIMEZONE	Time difference in the format hhmmss (in the data type FIXED(6)) between local time and UTC time.
UTCDIFF	Time difference in hours (in the data type FIXED(4,2)) between local time and UTC time.
TRUE \| FALSE	Corresponding value of a column of the data type BOOLEAN
TRANSACTION	Identification of the current transaction. This is a value of data type CHAR(6) BYTE.

More Information

Expression

Key specification

INSERT Statement

DEFAULT Specification