Обсуждение: @ operator
Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?
ps: sorry for my english
On Thursday, September 17, 2015, Антон Бушмелев <bushmelev.aa@gmail.com> wrote:
Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?
It would depend on what field1 is.
Typically <@ is a contains/contained-by operator. Is this context the subquery is checked to see if it contains the value of field1.
David J.
Your English is fine. @< is an "array is contained by" operator:
I assume that field1 is an array, as opposed to just a simple value variable. A simple value variable would be tested with something like: field1 IN ( subquery) . The @< tests that every value in the array field1 is also in the subquery. The subquery might contain other values, but it will contain _all_ values in field1.
On Thu, Sep 17, 2015 at 8:10 AM, Антон Бушмелев <bushmelev.aa@gmail.com> wrote:
Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?ps: sorry for my english
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Maranatha! <><
John McKown
On Thursday, September 17, 2015, David G. Johnston <david.g.johnston@gmail.com> wrote:
On Thursday, September 17, 2015, Антон Бушмелев <bushmelev.aa@gmail.com> wrote:Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?It would depend on what field1 is.Typically <@ is a contains/contained-by operator. Is this context the subquery is checked to see if it contains the value of field1.David J.
To clarify I think that it means that for each row returned by the subquery, the value of filed1 is checked to see if the field in the subquery contains the given value. Use use ANY/ALL to indicate whether to care if on,y so,e rows or all rows need match in order for the entire expression to pass.
David J.
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of ????? ????????
Sent: Thursday, September 17, 2015 9:11 AM
To: pgsql-general@postgresql.org
Cc: Антон Бушмелев <bushmelev.aa@gmail.com>
Subject: [GENERAL] @ operator
Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?
ps: sorry for my English
Could be absolute-value operator for numeric data types,
or array (or range) inclusion operator.
See PG docs (and these docs should be your first option, before googling):
http://www.postgresql.org/docs/9.4/static/typeconv-oper.html
Regards,
Igor Neyman
Thanks for reply, it is clear now =)
On 09/17/2015 08:34 PM, David G. Johnston wrote:
On Thursday, September 17, 2015, David G. Johnston <david.g.johnston@gmail.com> wrote:On Thursday, September 17, 2015, Антон Бушмелев <bushmelev.aa@gmail.com> wrote:Hello, google nothing for @ operator =(, what does this mean field1 <@ ( subquery ) ?It would depend on what field1 is.Typically <@ is a contains/contained-by operator. Is this context the subquery is checked to see if it contains the value of field1.David J.To clarify I think that it means that for each row returned by the subquery, the value of filed1 is checked to see if the field in the subquery contains the given value. Use use ANY/ALL to indicate whether to care if on,y so,e rows or all rows need match in order for the entire expression to pass.David J.