Re: 4.1. Lexical Structure - Mailing list pgsql-docs

From Yaroslav Saburov
Subject Re: 4.1. Lexical Structure
Date
Msg-id CAC2sXV9i0u5yVNPF-OKPriYkLUp3s8J2Bx=Ra7iDP7=pwM44Wg@mail.gmail.com
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In response to Re: 4.1. Lexical Structure  ("David G. Johnston" <david.g.johnston@gmail.com>)
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What should I look for?

postgres=# SELECT U&"d\0061t\+000061";
ERROR:  column "data" does not exist
LINE 1: SELECT U&"d\0061t\+000061";
               ^
postgres=# SELECT U&"\0441\043B\043E\043D";
ERROR:  column "слон" does not exist
LINE 1: SELECT U&"\0441\043B\043E\043D";
               ^
postgres=# SELECT U&"d!0061t!+000061" UESCAPE '!';
ERROR:  column "data" does not exist
LINE 1: SELECT U&"d!0061t!+000061" UESCAPE '!';


чт, 27 авг. 2026 г. в 17:54, David G. Johnston <david.g.johnston@gmail.com>:
On Thu, Aug 27, 2026 at 10:20 AM PG Doc comments form <noreply@postgresql.org> wrote:
The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/18/sql-syntax-lexical.html
Description:

Why repeat information within the same section?

4.1.1 and 4.1.2 are rightly written so as to keep them independent of one another.  It in part avoids wordiness in dealing with the fact that identifiers use double quotes while string literals use single quotes.


In Section 4.1.1, “Identifiers and Keywords”:

> U&“d\0061t\+000061”

This information, along with examples, is also provided in Section 4.1.2.3.
String Constants with Escaped Unicode Characters

> U&'d\0061t\+000061'


Thus while these are indeed both similar to each other the so-called repetition is warranted.

David J.


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