I am new with DB2.
I am not able to get data from a table without using the schema name. If I use a schema name with table name, I am able to fetch data.
Example:
SELECT * FROM TABLE_NAME;
It is giving me error, while
SELECT FROM SCHEMA_NAME.TABLE_NAME;
is fetching a result.
What do I have to set up not to always have to use the schema name?
By default, your username is used as the schema name for unqualified object names. You can see the current schema with, e.g. VALUES CURRENT SCHEMA. You can change the current schema for you current session with SET SCHEMA new_schema_name, or via e.g. a JDBC connection parameter. Most query tools also have a place to specify/change the current schema.
See the manual page for SET SCHEMA https://www.ibm.com/support/knowledgecenter/en/SSEPGG_11.1.0/com.ibm.db2.luw.sql.ref.doc/doc/r0001016.html
The full rules for the qualification of unqualified objects is here https://www.ibm.com/support/knowledgecenter/en/SSEPGG_11.1.0/com.ibm.db2.luw.sql.ref.doc/doc/r0000720.html#r0000720__unq-alias
E.g.
Unqualified alias, index, package, sequence, table, trigger, and view names are implicitly qualified by the default schema.
However, you can create a public alias for a table, module or sequence if you wish to be able to reference it regardless of your CURRENT SCHEMA value.
https://www.ibm.com/support/knowledgecenter/SSEPGG_11.5.0/com.ibm.db2.luw.sql.ref.doc/doc/r0000910.html
(P.S. all the above assumes you are using Db2 LUW)
Try using SET SCHEMA to set the default schema to be used in the session:
SET SCHEMA SCHEMA_NAME;
SELECT * FROM TABLE_NAME;
When using DBeaver - right click on connection > Connection Settings > Initialization, and select your default DB and default Schema:
After that, open your SQL Script and select Active DB:
Related
Can I use CREATE SCHEMA AUTHORIZATION for something other than the current user's schema?
I can do the following:
CREATE USER MAIN_USER
IDENTIFIED BY main_user_pass;
GRANT CREATE SESSION TO MAIN_USER;
GRANT CREATE TABLE TO MAIN_USER;
ALTER SESSION SET CURRENT_SCHEMA = MAIN_USER;
Query 1:
SELECT USER FROM DUAL;
Result 1:
SYS
Query 2:
SELECT sys_context( 'userenv', 'current_schema') FROM dual;
Result 2:
MAIN_USER
I can do this:
CREATE SCHEMA AUTHORIZATION SYS
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY);
Result:
Schema AUTHORIZATION created.
But when I try to do this, an error appears:
CREATE SCHEMA AUTHORIZATION MAIN_USER
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY);
Result:
ORA-02421: missing or invalid schema authorization identifier
02421. 00000 - "missing or invalid schema authorization identifier"
*Cause: the schema name is missing or is incorrect in an authorization
clause of a create schema statement.
*Action: If the name is present, it must be the same as the current
schema.
The error message is pretty clear: you can't do that. From the documentation:
The schema name must be the same as your Oracle Database username.
Setting current_schema only changes the default schema name prepended to an object reference in a SQL command that isn't fully qualified, so after setting it to MAIN_USER, this command:
select * table table_a;
would be interpreted as
select * from main_user.table_a;
instead of
select * from sys.table_a;
Setting current_schema doesn't actually change your logged in identity or affect your privileges in any way, and if sys can't execute a command like that against another schema then nobody can do it.
Can I use CREATE SCHEMA AUTHORIZATION for something other than the current user's schema?
No, you can't. The documentation says:
Use the CREATE SCHEMA statement to create multiple tables and views and perform multiple grants in your own schema in a single transaction.
This statement lets you populate your schema ...
Specify the name of the schema. The schema name must be the same as your Oracle Database username.
You have to be connected as the schema owner, so user returns MAIN_USER. Just changing your current schema with ALTER SESSION SET CURRENT_SCHEMA is not sufficient.
It also says:
To issue a CREATE SCHEMA statement, you must have the privileges necessary to issue the included statements.
and you have granted CREATE TABLE so that should work once you connect as that user. But it means you can't rely on the privileged SYS user's CREATE ANY privs to bypass the schema grants, which might have been an advantage had it been allowed to work as you hoped; if you want your user to end up without those privileges you'll have to grant them, run CREATE SCHEMA as that user, then revoke them again. Or go back to individual CREATE object statements, which you can run for another user as SYS - but without the all-or-nothing single-transaction benefit you get from CREATE SCHEMA.
When collaborating with colleagues I need to change the schema name every time I receive a SQL script (Postgres).
I am only an ordinary user of a corporate database (no permissions to change anything). Also, we are not allowed to create tables in PUBLIC schema. However, we can use (read-only) all the tables from BASE schema.
It is cumbersome for the team of users, where everybody is creating SQL scripts (mostly only for creating tables), which need to be shared amongst others. Every user has its own schema.
Is it possible to change the script below, where I will share the script to another user without the need for the other user to find/replace the schema, in this case, user1?
DROP TABLE IF EXISTS user1.table1;
CREATE TABLE user1.table1 AS
SELECT * FROM base.table1;
You can set the default schema at the start of the script (similar to what pg_dump generates):
set search_path = user1;
DROP TABLE IF EXISTS table1;
CREATE TABLE table1 AS
SELECT * FROM base.table1;
Because the search path was change to contain user1 as the first schema, tables will be searched in that schema when dropping and creating. And because the search path does not include any other schema, no other schema will be consulted.
If you
However the default search_path is "$user", public which means that any unqualified table will be searched or created in a schema with the same name as the current user.
Caution
Note that a DROP TABLE will drop the table in the first schema found in that case. So if table1 doesn't exist in the user's schema, but in the public schema, it would be dropped from the public schema. So for your use-case setting the path to exactly one schema might be more secure.
I am introducing spring to the existing application (hibernate has already been there) and encountered a problem with native SQL queries.
A sample query:
SELECT ST_MAKEPOINT(cast(longitude as float), cast(latitude as float)) FROM
OUR_TABLE;
OUR_TABLE is in OUR_SCHEMA.
When we connect to the db to OUR_SCHEMA:
spring.datasource.url: jdbc:postgresql://host:port/db_name?currentSchema=OUR_SCHEMA
the query fails because function ST_MAKEPOINT is not found - the function is located in schema: PUBLIC.
When we connect to the db without specifying the schema, ST_MAKEPOINT is found and runs correctly, though schema name needs to be added to the table name in the query.
As we are talking about thousands of such queries and all the tables are located in OUR_SCHEMA, is there a chance to anyhow specify the default schema, so still functions from PUBLIC schema were visible?
So far, I have tried the following springboot properties - with no success:
spring.jpa.properties.hibernate.default_schema: OUR_SCHEMA
spring.datasource.tomcat.initSQL: ALTER SESSION SET CURRENT_SCHEMA=OUR_SCHEMA
spring.datasource.initSQL: ALTER SESSION SET CURRENT_SCHEMA=OUR_SCHEMA
Also, it worked before switching to springboot config - specifying hibernate.default-schema = OUR_SCHEMA in persistence.xml was enough.
Stack:
spring-boot: 2.0.6
hibernate: 5.3.1.Final
postgresql: 42.2.5
postgis: 2.2.1
You're probably looking for the PostgreSQL search_path variable, which controls which schemas are checked when trying to resolve database object names. The path accepts several schema names, which are checked in order. So you can use the following
SET search_path=our_schema,public;
This will make PostgreSQL look for your tables (and functions!) first in our_schema, and then in public. Your JDBC driver may or may not support multiple schemas in its current_schema parameter.
Another option is to install the PostGIS extension (which provides the make_point() function) in the our_schema schema:
CREATE EXTENSION postgis SCHEMA our_schema;
This way you only have to have one schema in your search path.
JDBC param currentSchema explicitly allows specifying several schemas separating them by commas:
jdbc:postgresql://postgres-cert:5432/db?currentSchema=my,public&connectTimeout=4&ApplicationName=my-app
From https://jdbc.postgresql.org/documentation/head/connect.html
currentSchema = String
Specify the schema (or several schema separated by commas) to be set in the search-path. This schema will be used to resolve unqualified object names used in statements over this connection.
Note you probably need Postgres 9.6 or better for currentSchema support.
PS Probably better solution is to set search_path per user:
ALTER USER myuser SET search_path TO mydb,pg_catalog;
if you use hibernate.default_schema, then for native queries, you need to provide the {h-schema} placeholder, something like that
SELECT ST_MAKEPOINT(cast(longitude as float), cast(latitude as float)) FROM {h-schema}OUR_TABLE;
When I create a new SQL script , for example
select * from table
When I execute this the sql that gets ran is
SELECT * FROM MYNAME.TABLE
I understand DB2 does this , but I want the schema name to be concatenated onto the table names, not my username.
SELECT * FROM SCHEMANAME.TABLE
It did this for me before, but I dont know what changed that it now only puts the database username at the end of the tables.
Does anyone know how to set it so the schema name gets added on?
Best way in my eyes for Data Stuio is setting the special register "Current schema" on the Special Registers tab of the SQL Editor. Here is a screenshot
Schema name defaults to your authorisation ID (user name in most cases). To use a different name to qualify unqualified object names, set the special register CURRENT_SCHEMA appropriately:
SET SCHEMA whatever
Could you try this;
In Data Project Explorer,
right clicked, properties
Driver properties
type your schema in Default schema
disconnect and reconnect database;
and try without SCHEMANAME.
I'm currently using a schema that will be changed to another schema in a couple of months. I do not not want to have to remove the SCHEMA_NAME multiple times from each report. All the reports so far have this format:
SELECT
COLUMN_NAME1,
SCHEMA_NAME.USER_DEFINED_FUNCTION(COLUMN_NAME2),
COLUMN_NAME3
FROM
SCHEMA_NAME.TABLE_NAME
I want to remove the schema name from the query so it looks like this:
SET SCHEMA LROUIM;
SET PATH LROUIM;
SELECT
COLUMN_NAME1,
USER_DEFINED_FUNCTION(COLUMN_NAME2),
COLUMN_NAME3
FROM
TABLE_NAME
I need the "SET SCHEMA" for the table name and "SET PATH" for the User Defined Function. This code works in Squirrel SQL, but if I insert this code into a Birt data set of type SQL SELECT QUERY, I get an error because of
SET SCHEMA LROUIM;
SET PATH LROUIM;
How do I implement SET SCHEMA and SET PATH in a SQL Select Query in Birt?
I think BIRT uses a JDBC connexion, and you can modify the connection parameters by specifying a default schema.