Re: public synonym

On 01/07/2016 12:27 PM, michael(at)sqlexec(dot)com wrote:
> You can infer the context by first setting the search_path variable.
> You can set it initially in your connection or do it for a database
> context or even a role context
> SET search_path = MASTER_USER, public, pg_catalog;
> ALTER DATABASE whatever SET search_path = MASTER_USER, public, pg_catalog;
> ALTER ROLE whoever SET search_path = MASTER_USER, public, pg_catalog;

Just be aware that Postgres folds identifiers to lower case:

test=# create schema MASTER_USER;
CREATE SCHEMA
test=# \dn
List of schemas
Name | Owner
-------------+----------
master_user | postgres
public | postgres

test=# create table MASTER_USER.test_tbl(id int);
CREATE TABLE

test=# \d master_user.test_tbl
Table "master_user.test_tbl"
Column | Type | Modifiers
--------+---------+-----------
id | integer |

UNLESS the tool you are using to create objects quotes the object name:

test=# create schema "MASTER_USER";
CREATE SCHEMA

test=# create table MASTER_USER.test_tbl(id int);
ERROR: schema "master_user" does not exist

test=# create table "MASTER_USER".test_tbl(id int);
CREATE TABLE

test=# \d "MASTER_USER".test_tbl
Table "MASTER_USER.test_tbl"
Column | Type | Modifiers
--------+---------+-----------
id | integer |

More details at:

http://www.postgresql.org/docs/9.4/static/sql-syntax-lexical.html

4.1.1. Identifiers and Key Words

>
> Then you can continue to let the tables be non-qualified. bye bye
> synonyms!
>
> Regards
> Michael
>> Eugene Yin <mailto:eugeneymail(at)ymail(dot)com>
>> Thursday, January 7, 2016 3:17 PM
>> PostgreSQL ver 9.4.5. Linux OS.
>> Application: Web Based
>>
>> Platform:
>> App Server (java) --> jdbc call --> Database Server (PostgreSQL)
>>
>>
>> I do know that PostgreSQL does not support the public synonym.Now, for
>> a user schema (let's call it MASTER_USER), if I coded in the stored
>> function/procedure like the following, without using a public synonym
>> to identify the table name:
>>
>> select user_name from user_info_table
>>
>> then access it from the Java (web app) sidevia the JDBC call to the
>> database, will that work?
>>
>> OR,
>>
>> I must use the identifier inside the sql, such as:
>>
>> select user_name fromMASTER_USER.user_info_table?
>>
>>
>> I come from the Oracle world, there I first create the public synonym
>> for the table, then in the stored procedure I just directly reference
>> the table with no need to identify the table with a schema name. Like
>> to know how it work under the PostgreSQL.
>>
>>
>> Thanks
>>
>> Eugene
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com