As the title entails, is this possible?
Using the following code returns a list of the built-in schemas as well as all the other schemas:
select name from MyDbName.sys.schemas
What I want is only the schemas I created for each table. I also tried doing the following code but its not very solid.
select name from MyDbName.sys.schemas where name not like '%db_%'
select distinct SCHEMA_NAME(schema_id) from sys.objects
I think this will work for you.
Related
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
In AWS Athena you can write
SHOW CREATE TABLE my_table_name;
and see a SQL-like query that describes how to build the table's schema. It works for tables whose schema are defined in AWS Glue. This is very useful for creating tables in a regular RDBMS, for loading and exploring data views.
Interacting with Athena in this way is manual, and I would like to automate the process of creating regular RDBMS tables that have the same schema as those in Redshift Spectrum.
How can I do this through a query that can be run via psql? Or is there another way to get this via the aws-cli?
Redshift Spectrum does not support SHOW CREATE TABLE syntax, but there are system tables that can deliver same information. I have to say, it's not as useful as the ready to use sql returned by Athena though.
The tables are
svv_external_schemas - gives you information about glue database mapping and IAM roles bound to it
svv_external_tables - gives you the location information, and also data format and serdes used
svv_external_columns - gives you the column names, types and order information.
Using that data, you could reconstruct the table's DDL.
For example to get the list of columns and their types in the CREATE TABLE format one can do:
select distinct
listagg(columnname || ' ' || external_type, ',\n')
within group ( order by columnnum ) over ()
from svv_external_columns
where tablename = '<YOUR_TABLE_NAME>'
and schemaname = '<YOUR_SCHEM_NAME>'
the query give you the output similar to:
col1 int,
col2 string,
...
*) I am using listagg window function and not the aggregate function, as apparently listagg aggregate function can only be used with user defined tables. Bummer.
I had been doing something similar to #botchniaque's answer in the past, but recently stumbled across a solution in the AWS-Labs' amazon-redshift-utils code package that seems to be more reliable than my hand-spun queries:
amazon-redshift-utils: v_generate_external_tbl_ddl
If you don't have the ability to create a view backed with the ddl listed in that package, you can run it manually by removing the CREATE statement from the start of the query. Assuming you can create it as a view, usage would be:
SELECT ddl
FROM admin.v_generate_external_tbl_ddl
WHERE schemaname = '<external_schema_name>'
-- Optionally include specific table references:
-- AND tablename IN ('<table_name_1>', '<table_name_2>', ..., '<table_name_n>')
ORDER BY tablename, seq
;
They added show external table now.
SHOW EXTERNAL TABLE external_schema.table_name [ PARTITION ]
SHOW EXTERNAL TABLE my_schema.my_table;
https://docs.aws.amazon.com/redshift/latest/dg/r_SHOW_EXTERNAL_TABLE.html
I create this table 'friend' with PgAdmin III. I would like to select all the data where the word 'grand' is contained in the columns keywords.
I tried the following:
SELECT * FROM friend where keywords LIKE 'grand';
but it does not work, i don't receive any results.
Would someone have any ideas ?
Thank you
Use wildcards:
select *
from friend
where keywords like '%grand%';
Read more in the documentation.
Trying to be lazy when looking at an example
SELECT realestate.address, realestate.parcel, s.sale_year, s.sale_amount,
FROM realestate INNER JOIN
dblink('dbname=somedb port=5432 host=someserver
user=someuser password=somepwd',
'SELECT parcel_id, sale_year,
sale_amount FROM parcel_sales')
AS s(parcel_id char(10),sale_year int, sale_amount int)
Is there a way of getting the AS section filled in from the table?
I'm copying data from tables of the same name and structure on different servers.
If I can get the structure to copy from the existing table, it will save me a lot of time
Thanks
Bruce
The answer is: No. See the doc:
Since dblink can be used with any query, it is declared to return record, rather than specifying any particular set of columns. This means that you must specify the expected set of columns in the calling query — otherwise PostgreSQL would not know what to expect.
http://www.postgresql.org/docs/9.1/static/contrib-dblink-function.html
Edit: by the way, for a table or a view, you can get the fields name and type in a first query:
select column_name
from information_schema.columns
where table_name = 'your_table_or_view';
You could then use it to fill the fields declaration.
Alexis
oracle has 'DESCRIBE' to get all the details of the table like wise does t/sql has any thing.
SQL Server has sp_help/sp_helptext
MySQL has describe
Sql-Server's sp_help is about as close as you get for something built-in. Remeber to put the tablename in as a parameter...:-)
EXEC sp_help 'mytable'
If you're in ssms, you can r-click your query window and opt to output results to text -- it's a little easier to read the output.
ms-help://MS.SQLCC.v10/MS.SQLSVR.v10.en/s10de_6tsql/html/913cd5d4-39a3-4a4b-a926-75ed32878884.htm
Also -- you can write your own using the system tables (sys.objects, sys.columns, ...) I think 'DESCRIBE' just gives you column name, nullable, and type... so not nearly as much as sp_help provides.
SELECT * FROM sysobjects WHERE parent_obj = (SELECT id FROM sysobjects WHERE name = 'table_name') AND xtype='PK'
will show table details.
SELECT * FROM sys.Tables
will list all tables
There is no describe equivalent.
you might find this searching for MSSQL instead of T/SQL. Most people talking about Transact SQL are talking about stored procedures.