How to insert data into `group` labeled table - postgresql

I have a database in Postgres that has multiple tables. One of them is group. I know that this is a reserved name. The question is how to insert data into that table.

As documented in the manual you need to use double quotes:
insert into "group" (column_1, column_2)
values (42, 'foo');

Related

DB2 Temp Table - Retrieving inserted Data in DB2 Z OS

I have created a temp table and Inserted in DB2 ZOS as mentioned below
CREATE GLOBAL TEMPORARY TABLE tmp2 (col1 INT)
INSERT INTO tmp2 (col1) VALUES (10687);
INSERT INTO tmp2 (col1) VALUES (10689);
INSERT INTO tmp2 (col1) VALUES (10691);
Inserted data with out any issues, where I'm trying to retrieve the data using select query Im unable see any values which I had inserted with the above values and getting.
select * from tmp2
I have an earlier experience in SQL Server and ran the below queries which work without any issues.
Drop table #tmp2
CREATE TABLE #tmp2 (col1 INT)
INSERT INTO #tmp2 (col1) VALUES (10687);
INSERT INTO #tmp2 (col1) VALUES (10689);
INSERT INTO #tmp2 (col1) VALUES (10691);
select * from #tmp2
How to get to see the inserted data?
Check the documentation for details, sometimes this is faster than waiting for an answer.
The CGTT (create global temporary table) object differs from a regular table when a COMMIT happens - it will empty the table if there are no with hold cursors open on the table. If you have autocommit enabled for your database connection then the result will be that your CGTT table may appear to be empty.
If you want more control over the commit behaviour (and rollback behaviour, and logging options etc. ) you can consider using DGTT (declare global temporary table) instead because that syntax lets you use additional non-default options like on commit preserve rows and on rollback preserve rows. But a DGTT object has more restrictions , including that its qualifier must always be SESSION and its definition is not catalogued so the table is invisible to any other session.
Thanks for all replies.
Below is the set of queries, actually I was looking for
DECLARE GLOBAL TEMPORARY TABLE SESSION.tmp2 (col1 INTEGER)
CCSID EBCDIC ON COMMIT PRESERVE ROWS;
INSERT INTO SESSION.tmp2 (col1) VALUES (10687);
INSERT INTO SESSION.tmp2 (col1) VALUES (10689);
INSERT INTO SESSION.tmp2 (col1) VALUES (10691);
select * from SESSION.tmp2;

Is there a way to change the datatype for a column without changing the order of the column?

I have a column where I want to change the data type. I currently am using Redshift. I know I can use the alter table statement to change the datatype, but this would change the order of the columns.
Is there a way to change the datatype without changing the order of the column?
I would recommend creating a new table with the schema you want and copying it over from the old table using a insert into new_table (select * from old_table) statement (here you can also do any casting to the new data type), after which you can drop the old table and rename the new one:
drop table old_table;
alter table new_table rename to old_table;
Using ALTER TABLE table_name ALTER COLUMN column_name TYPE new_data_type will not change the order of the columns in your table.
Please note that this clause can only changes the size of a column defined as a VARCHAR data type.
There are also other limitations described in AWS documentation of ALTER TABLE

Delete column in hive table

I am working with hive version 0.9 and I need delete columns of a hive table. I have searched in several manuals of hive commands but I only I have found commands to version 0.14. Is possible to delete a column of a hive table in hive version 0.9? What is the command?
Thanks.
We can’t simply drop a table column from a hive table using the below statement like sql.
ALTER TABLE tbl_name drop column column_name ---- it will not work.
So there is a shortcut to drop columns from a hive table.
Let’s say we have a hive table.
From this table I want to drop the column Dob. You can use the ALTER TABLE REPLACE statement to drop a column.
ALTER TABLE test_tbl REPLACE COLUMNS(ID STRING,NAME STRING,AGE STRING); you have to give the column names which you want to keep in the table
There isn't a drop column or delete column in Hive.
A SELECT statement can take regex-based column specification in Hive releases prior to 0.13.0, or in 0.13.0 and later releases if the configuration property hive.support.quoted.identifiers is set to none.
That being said you could create a new table or view using the following:
drop table if exists database.table_name;
create table if not exists database.table_name as
select `(column_to_remove_1|...|column_to_remove_N)?+.+`
from database.some_table
where
...
;
This will create a table that has all the columns from some_table except the columns named column_to_remove_1, ... , to column_to_remove_N. You can also choose to create a view instead.
ALTER TABLE table_name REPLACE COLUMNS ( c1 int, c2 String);
NOTE: eliminate column from column list. It will keep matched columns and removed unmentioned columns from table schema.
we can not delete column from hive table . But droping a table(if its external) in hive and the recreating table(with column excluded) ,wont delete ur data .
so what can u do is(if u dont have table structure) run this command :
show create table database_name.table_name;
Then you can copy it and edit it (with column eliminated).Afterwards you can do as per invoke the shell
table details are empid,name,dept,salary ,address. i want remove address column. Just write REPLACE COLUMNS like below query
jdbc:hive2://> alter table employee replace columns(empid int, name string,dept string,salary int);
As mentioned before, you can't drop table using an alter statement.
Alter - replace is not guaranteed to work in all the cases.
I found the best answer for this here:
https://stackoverflow.com/a/48921280/4385453

Inserting multiple records and updating identity column in SQL

i have to insert multiple records into a table and in the mean time needed to insert the identity column of the first table in to another table.Can i do it avoiding loop?
Edited
i have two tables named StudentMaster and StudentSujects.
First Table structure is (StudentID int Identity(1,1),StudentName varchar(100))
Second table structure is (SubjectID int Identity(1,1),StudentID int,SubjectName varchar(100)).
StudentID in the 'StudentSujects' table is the Identity column of first table 'StudentMaster'.
INSERT INTO StudentMaster
(
StudentName
)
SELECT StudentName
FROM OPENXML(#hDoc,'/XML/Students')
WITH( StudentName varchar(100) 'StudentName')
I am inserting multiple records in to the first table using the above query.I the mean time i have to insert the identity column of each row in to the second table.
You can use the OUTPUT clause to output multiple columns/rows on an INSERT operation into a table variable.
Assuming your table that you're inserting into has an IDENTITY column called ID, you could have code something like this:
DECLARE #InsertedData TABLE (NewID INT, SomeOtherColumn.....)
INSERT INTO dbo.YourTable(Col1, Col2, ..., ColN)
OUTPUT INTO #InsertedData(NewID, SomeOtherColumn) Inserted.ID, Inserted.OtherColumn
VALUES(Val11, Val12, ..., Val1N),
(Val21, Val22, ..., Val2N),
....
(ValM1, ValM2, ..., ValMN)
Of course, you need to have something that allows you to identify which row in your second table to insert which value into - that's entirely dependent on your situation (and you didn't offer any explanation of that in your question).
But basically, using the OUTPUT clause, you can capture as much information as you need, including the newly assigned IDENTITY values, so that you can then do your second insert based on that information.

Is there a way to quickly duplicate record in T-SQL?

I need to duplicate selected rows with all the fields exactly same except ID ident int which is added automatically by SQL.
What is the best way to duplicate/clone record or records (up to 50)?
Is there any T-SQL functionality in MS SQL 2008 or do I need to select insert in stored procedures ?
The only way to accomplish what you want is by using Insert statements which enumerate every column except the identity column.
You can of course select multiple rows to be duplicated by using a Select statement in your Insert statements. However, I would assume that this will violate your business key (your other unique constraint on the table other than the surrogate key which you have right?) and require some other column to be altered as well.
Insert MyTable( ...
Select ...
From MyTable
Where ....
If it is a pure copy (minus the ID field) then the following will work (replace 'NameOfExistingTable' with the table you want to duplicate the rows from and optionally use the Where clause to limit the data that you wish to duplicate):
SELECT *
INTO #TempImportRowsTable
FROM (
SELECT *
FROM [NameOfExistingTable]
-- WHERE ID = 1
) AS createTable
-- If needed make other alterations to the temp table here
ALTER TABLE #TempImportRowsTable DROP COLUMN Id
INSERT INTO [NameOfExistingTable]
SELECT * FROM #TempImportRowsTable
DROP TABLE #TempImportRowsTable
If you're able to check the duplication condition as rows are inserted, you could put an INSERT trigger on the table. This would allow you to check the columns as they are inserted instead of having to select over the entire table.