Обсуждение: Using DSN Connection and knowing windows username

On Wednesday, June 20, 2018, Łukasz Jarych <jaryszek@gmail.com> wrote:

How to know in postgresql which specific windows user is using database? 

You cannot.  All the server knows is the specific user credentials it is authenticating.

That said you can authenticate those credentials in such a way so that knowing the signed on user you would also know who they are in any environment that uses the same authentication source - and if that source supplies their Windows identity you are golden. The specific setups involved here are outside my experience, though.

David J.

On 06/20/2018 07:06 AM, Łukasz Jarych wrote:

David G,

thank you.
Can you confirm if i am thinking correctly ?

So I can set up authetification to know which user is logged on and use this as postgresql user?

Only if the system user is a postgres user or can be mapped to one:

https://www.postgresql.org/docs/10/static/auth-username-maps.html

But i think it will be not possible to use DSN connection with this.

If you are talking about the ODBC DSN you use to create the linked table in Access then you are correct you are limited to whatever user is specified in the ODBC Manager.

It would help to know what you plan to use the user name for?

In the meantime just an idea, but could you capture the system user in a table in Access and use that to pass on to Postgres?

Best ,
Luke

2018-06-20 15:34 GMT+02:00 David G. Johnston <david.g.johnston@gmail.com <mailto:david.g.johnston@gmail.com>>:

    On Wednesday, June 20, 2018, Łukasz Jarych <jaryszek@gmail.com
    <mailto:jaryszek@gmail.com>> wrote:

        How to know in postgresql which specific windows user is using
        database?

    You cannot.  All the server knows is the specific user credentials
    it is authenticating.

    That said you can authenticate those credentials in such a way so
    that knowing the signed on user you would also know who they are in
    any environment that uses the same authentication source - and if
    that source supplies their Windows identity you are golden. The
    specific setups involved here are outside my experience, though.

    David J.

--
Adrian Klaver
adrian.klaver@aklaver.com

Thank you Adrian,

In the meantime just an idea, but could you capture the system user in a table in Access and use that to pass on to Postgres?

Brilliant ! simple and genious!

The purpose of it is to have history log table with DML and DDL changes using triggers. 

Best,

Luke

2018-06-21 0:11 GMT+02:00 Adrian Klaver <adrian.klaver@aklaver.com>:

On 06/20/2018 07:06 AM, Łukasz Jarych wrote:

David G,

thank you.
Can you confirm if i am thinking correctly ?

So I can set up authetification to know which user is logged on and use this as postgresql user?

Only if the system user is a postgres user or can be mapped to one:

https://www.postgresql.org/docs/10/static/auth-username-maps.html

But i think it will be not possible to use DSN connection with this.

If you are talking about the ODBC DSN you use to create the linked table in Access then you are correct you are limited to whatever user is specified in the ODBC Manager.

It would help to know what you plan to use the user name for?

In the meantime just an idea, but could you capture the system user in a table in Access and use that to pass on to Postgres?

Best ,
Luke

2018-06-20 15:34 GMT+02:00 David G. Johnston <david.g.johnston@gmail.com <mailto:david.g.johnston@gmail.com>>:

    On Wednesday, June 20, 2018, Łukasz Jarych <jaryszek@gmail.com
    <mailto:jaryszek@gmail.com>> wrote:

        How to know in postgresql which specific windows user is using
        database?

    You cannot.  All the server knows is the specific user credentials
    it is authenticating.

    That said you can authenticate those credentials in such a way so
    that knowing the signed on user you would also know who they are in
    any environment that uses the same authentication source - and if
    that source supplies their Windows identity you are golden. The
    specific setups involved here are outside my experience, though.

    David J.

--
Adrian Klaver
adrian.klaver@aklaver.com

Hmm one problem. 

How to distinct value for specific user? 

I created new table in postgresql and when user is login into system New value is added to field "System_user". 

But how to show postgresql database that should use the specific value (for inputing data user, not for others?). 

Best,

Luke

2018-06-21 6:15 GMT+02:00 Łukasz Jarych <jaryszek@gmail.com>:

Thank you Adrian,

In the meantime just an idea, but could you capture the system user in a table in Access and use that to pass on to Postgres?

Brilliant ! simple and genious!

The purpose of it is to have history log table with DML and DDL changes using triggers. 

Best,

Luke

2018-06-21 0:11 GMT+02:00 Adrian Klaver <adrian.klaver@aklaver.com>:

On 06/20/2018 07:06 AM, Łukasz Jarych wrote:

David G,

thank you.
Can you confirm if i am thinking correctly ?

So I can set up authetification to know which user is logged on and use this as postgresql user?

Only if the system user is a postgres user or can be mapped to one:

https://www.postgresql.org/docs/10/static/auth-username-maps.html

But i think it will be not possible to use DSN connection with this.

If you are talking about the ODBC DSN you use to create the linked table in Access then you are correct you are limited to whatever user is specified in the ODBC Manager.

It would help to know what you plan to use the user name for?

In the meantime just an idea, but could you capture the system user in a table in Access and use that to pass on to Postgres?

Best ,
Luke

2018-06-20 15:34 GMT+02:00 David G. Johnston <david.g.johnston@gmail.com <mailto:david.g.johnston@gmail.com>>:

    On Wednesday, June 20, 2018, Łukasz Jarych <jaryszek@gmail.com
    <mailto:jaryszek@gmail.com>> wrote:

        How to know in postgresql which specific windows user is using
        database?

    You cannot.  All the server knows is the specific user credentials
    it is authenticating.

    That said you can authenticate those credentials in such a way so
    that knowing the signed on user you would also know who they are in
    any environment that uses the same authentication source - and if
    that source supplies their Windows identity you are golden. The
    specific setups involved here are outside my experience, though.

    David J.

--
Adrian Klaver
adrian.klaver@aklaver.com

On 06/21/2018 01:33 AM, Łukasz Jarych wrote:

Hi Guys,

the best option here i think is to:

1. Create users login in Access
2. Use DSN-less odbc connection.
3. When user is login to Access i am taking password and using it in postgresql BE.

That would work as long as the user name and password used to login into Access are also recognized by Postgres.

Best,
Luke

--
Adrian Klaver
adrian.klaver@aklaver.com