Re: How to write such a query?

Ron <ronljohnsonjr@xxxxxxxxx> · Thu, 6 Jan 2022 01:14:36 -0600

    On 1/6/22 1:06 AM, Igor Korot wrote:

      Hi, Ron,

On Thu, Jan 6, 2022 at 1:01 AM Ron <ronljohnsonjr@xxxxxxxxx> wrote:

        On 1/6/22 12:39 AM, Igor Korot wrote:

          Hi, ALL,
In SQLite you can write:

SELECT a, b, c FROM foo WHERE id = :id;

where ":id" is the named parameter.

The query above is similar to

SELECT a,b,c FROM foo WHERE id = ?;

except that the parameter has a name.

Is there a way to write such a SELECT statement with the
named parameter in PostgreSQL?

        Absolutely.  Of course, the exact method depends on the client.  Are you
referring to psql?

If so, then here's an example:
$ psql12 -v S=456789012 test
psql (12.8 (Ubuntu 12.8-1.pgdg18.04+1))
Type "help" for help.

test=# select * from employee where ssn = :'S';
     ssn    |      name       |  ssn_int
-----------+-----------------+-----------
  456789012 | Fred Flintstone | 456789012
(1 row)

In this case, column ssn is of type varchar(9).

      Is the syntax available since 9.0+? Or later?
I'm writing C++.

    Like I said before... "the exact method depends on the client".  The
    C++ client library is not the same as the psql application.

    IOW, read the C+ client library documentation.

    -- 

      Angular momentum makes the world go 'round.