Identifier

An identifier specifies the unqualified name of a database object, such as an access method, aggregate, alias, blobspace, cast, column, constraint, correlation, data type, index, operator class, optimizer directive, partition, procedure, table, trigger, sequence, synonym, or view. Use the Identifier segment whenever you see a reference to an identifier in a syntax diagram.

Syntax

Identifier:
 
|--+-+-letter-----+--+----------------------------+-+-----------|
   | '-underscore-'  | .------------------------. | |
   |                 | V                        | | |
   |                 '---+-letter-------------+-+-' |
   |                     +-digit--------------+     |
   |                     +-underscore---------+     |
   |                     |  (1)               |     |
   |                     '--------dollar_sign-'     |
   |                          (2)                   |
   '-| Delimited Identifier |-----------------------'

Notes:

Dynamic Server only
See Delimited Identifiers

Element	Description	Restrictions	Syntax
digit	Integer in range `0` to `9`	Cannot be the first character	Literal Number
dollar_sign	Dollar ( $ ) symbol	Cannot be the first character	Literal symbol entered from the keyboard.
letter	Upper- or lowercase letter of the alphabet	In the default locale, must be an ASCII character in the range A to Z or a to z	Literal symbol entered from the keyboard.
underscore	Underscore ( _ ) character	Cannot substitute a space, hyphen, or other non-alphanumeric character	Literal symbol entered from the keyboard.

Usage

This is a logical subset of Database Object Name, a segment that can specify the owner, database, and database server of external objects.

To include other non-alphanumeric symbols, such as a blank space (ASCII 32), in an identifier, you must use a delimited identifier. It is recommended that you do not use the dollar sign ( $ ) in identifiers, because this symbol is a special character whose inclusion in an identifier might cause conflicts with other syntax elements. For more information, see Delimited Identifiers.

An identifier must have a length of at least 1 byte, but no more than 128 bytes. For example, employee_information is valid as a table name. If you are using a multibyte code set, keep in mind that the maximum length of an identifier refers to the number of bytes, not to the number of logical characters.

For letter characters in nondefault locales, see Support for Non-ASCII Characters in Identifiers. For further information on the GLS aspects of identifiers, see Chapter 3 of the IBM Informix GLS User's Guide.

When you use ESQL/C with Dynamic Server, the database server checks the internal version number of the client application and the setting of the IFX_LONGID environment variable to determine whether a client application supports long identifiers (up to 128 bytes in length). For more information, see the IBM Informix Guide to SQL: Reference.