Delimited identifiers

Delimited identifiers are object names enclosed in double quotes. Using delimited identifiers allows you to avoid certain restrictions on object names. You can use double quotes to delimit table, view, and column names; you cannot use them for other database objects.

Delimited identifiers can be reserved words, can begin with nonalphabetic characters, and can include characters that would not otherwise be allowed. They cannot exceed 253 bytes. A pound sign (#) is illegal as a first character of any quoted identifier. (This restriction applies to Adaptive Server 11.5 and all later versions.)

Before you create or reference a delimited identifier, you must execute:

set quoted_identifier on

This allows Adaptive Server to recognize delimited identifiers. Each time you use the quoted identifier in a statement, you must enclose it in double quotes. For example:

create table "1one"(col1 char(3))
select * from "1one"
create table "include spaces" (col1 int)

While the quoted_identifier option is turned on, do not use double quotes around character or date strings; use single quotes instead. Delimiting these strings with double quotes causes Adaptive Server to treat them as identifiers. For example, to insert a character string into col1 of 1onetable, use:

insert "1one"(col1) values ('abc')

not:

insert "1one"(col1) values ("abc")

To insert a single quote into a column, use two consecutive single quotation marks. For example, to insert the characters “a’b” into col1, use:

insert "1one"(col1) values(’a’’b’)

Syntax that includes quotes

When the quoted_identifier option is set to on, you need not use double quotes around an identifier if the syntax of the statement requires that a quoted string contain an identifier. For example:

create table '1one' (c1 int)

The quotes are included in the name of table '1one':

select object_id('1one')

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You can include an embedded double quote in a quoted identifier by doubling the quote:

create table "embedded""quote" (c1 int)

However, there is no need to double the quote when the statement syntax requires the object name to be expressed as a string:

select object_id('embedded"quote')

Bracketed delimited identifiers

Sybase also supports bracketed identifiers, whose behavior is identical to that of quoted identifiers, with the exception that one need not set quoted_identifier on in order to use them.

create table [bracketed identifier](c1 int)

This bracket enhancement increases platform compatibility.

Copyright © 2005. Sybase Inc. All rights reserved.

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