I want to fetch column names of a table using HQL and populate the same in a list?..Please guide. I am using IBM DB2 database.
I have not tested, but you can query the DB2 catalog in order to get the metadata. If you execute the equivalent in HQL, it should work
select colname
from syscat.columns
where tabschema like 'MYSCHEMA%' and tabname = 'MYTABLE'
order by colno
Related
I got a Postgres database with multiple schemas. I'm trying to optimise my database tables with optimal data types. more often I end with the error
cannot alter the type of a column used by a view
while using the query alter table schema.tbl_name alter column column_name type varchar(5) using column_name::varchar(5);
Is there any way (function) that I could list all the views related to the table?
Use this query:
select
u.view_schema schema_name,
u.view_name,
u.table_schema referenced_table_schema,
u.table_name referenced_table_name,
v.view_definition
from information_schema.view_table_usage u
join information_schema.views v on u.view_schema = v.table_schema
and u.view_name = v.table_name
where u.table_schema not in ('information_schema', 'pg_catalog')
order by u.view_schema, u.view_name
Credit: Dataedo.com's article List tables used by a view in PostgreSQL database
Is there a way to find all table names that begin with t_ in a given schema name with criteria API or query DSL( or even database metadata)? If it exists, could you please show me how I can do it using a schema name or view? I'm using PostgreSQL for the database.
I don't want to use a native query.
yes, you can use below query:
SELECT table_catalog,table_schema,table_name
FROM information_schema.tables
WHERE table_name LIKE 't\_%'
AND table_type='BASE TABLE' -- to filter out Tables only, remove if you need to see views as well
I am using Teiid vdb model where i need to extract query constraints inside the ddl and use it in a stored procedure to fetch results of my choice. For example, if I run following query :
select * from Student where student_name = 'st123', i want to pass st123 to my procedure and return the results based on some processing.
How can i extract this constraint inside the ddl instead of teiid doing the filtering for me and returning the matching row. Is there a way around developing the connector and handling this in vdb instead?
See http://teiid.github.io/teiid-documents/master/content/reference/r_procedural-relational-command.html
If you have the procedure:
create virtual procedure student (in student_name string) returns table (<some cols>) as
begin
if (student_name like '...')
...
end
then you can all it as if it were a table:
select * from student where student_name = 'st123'
I have a postgres DB and inside of it there are many schemas.
Each one of those schemas contains tables. For example:
Schema Name: personal has tables actions_takes, page_views etc
How can i write a SQL query or ActiveRecord query to query the table inside the schema?
Something like:
select * from actions_takes where user_id = 123;
I can create a model for each table and query it that way, but i want to write a script that passed a user goes over all tables and get the data for that user.
in pgAdmin 4 web console should use double quotation marks like following select statement
SELECT "col1", "col2"
FROM "schemaName".profile;
Point to specific table within a given schema using a dot notation schema.table_name. In your case it translates to
select * from personal.actions_takes where user_id = 123;
For me this query worked : select * from schemaName."Table_Name"
I am unable to write a query in oracle SQL 10_g which uses all types of constraints using employees and departments tables.
Can you help me with the same?
Do you mean:
select * from all_constraints
where table_name in ('EMPLOYEES', 'DEPARTMENTS');