Re: why semicolon after begin is not allowed in postgresql?

Поиск
Список
Период
Сортировка
От Andrew Dunstan
Тема Re: why semicolon after begin is not allowed in postgresql?
Дата
Msg-id 528FDE60.40300@dunslane.net
обсуждение исходный текст
Ответ на why semicolon after begin is not allowed in postgresql?  (AK <alkuzo@gmail.com>)
Список pgsql-hackers
On 11/22/2013 05:24 PM, AK wrote:
> I am reading the following in the documentation: "Tip: A common mistake is to
> write a semicolon immediately after BEGIN. This is incorrect and will result
> in a syntax error."
>
> So, "common mistake" means semicolons after BEGIN seem consistent to many
> people - it seems consistent to me as well. If PostgreSql allowed them, we
> would have one less rule to memorize, shorter documentation, less mistakes
> and so on. In other words, without this limitation PostgreSql would be
> slightly more useful, right?
>
> What am I missing? Why do we need this rule? How is it making PostgreSql
> better?
>
>
>


You're referring specifically to plpgsql, not to Postgres or SQL generally.

plpgsql is derived from PLSQL which is derived from Ada which has this 
grammatical rule.

The explanation is this: only complete statements are followed by 
semicolons. But in these languages, "begin" on its own is not a complete 
statement. It's the start of a compound statement, the end of which will 
be "end", which is indeed followed by a semicolon.

cheers

andrew



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Kevin Grittner
Дата:
Сообщение: Re: why semicolon after begin is not allowed in postgresql?
Следующее
От: Bruce Momjian
Дата:
Сообщение: Re: Patch for fail-back without fresh backup