I would like to add a column with values to an existing table in Qlikview, with no KeyValues between them.
These are the columns of table 1
Column1 | Column2|
1 Q
2 Z
3 T
This is the column I want to append from table2, to table 1
Column3|
ret
ret
ret
This is how it should look like after appending
Column1 | Column2| Column3 |
1 Q ret
2 Z ret
3 T ret
Try to append this:
join load "ret" as column3 autogenerate 1;
Related
Just as in oracle database we have column_id in all_tabs_columns is there a similar field for postgresql?
For example if in oracle we can order by column id by selecting from columns do we have a similar query in pgsql ?
The column attnum in pg_attribute shows the order of a column in a table.
yes, you can also order by column number in Postgres:
with sampledata(a,b) as (values (1,'z'),(2,'y'),(3,'x'))
SELECT a,b
FROM sampledata
ORDER BY 1;
a | b
---+---
1 | z
2 | y
3 | x
(3 rows)
with sampledata(a,b) as (values (1,'z'),(2,'y'),(3,'x'))
SELECT a,b
FROM sampledata
ORDER BY 2;
a | b
---+---
3 | x
2 | y
1 | z
(3 rows)
The closest equivalent to all_tab_columns is information_schema.columns
So you are probably looking for something along the lines:
select column_name
from information_schema.columns
where table_name = '...'
order by ordinal_position;
In postgresql. Let's say you have a table with the name Table with the following columns:
Col 1,
Col 2,
Col 3
You can completely reorder the columns in postgresql by writing the query
SELECT
Col 3,
Col 2,
Col 1
FROM
Table
I am trying the following with Db2:
Problem
So I've got a table with 80+ columns and two rows.
I need to accomplish is checking what columns have changed value between the two rows, and return a table of the column names that have changed, their initial value from row1, and their new value from row2.
Approach so far
My initial idea was to perform a pivot of the two rows into two columns, row 1 as column 1, row 2 as column 2, then join a column of column names (likely taken from syscat.columns) to the table as column 3, at which point I can then do a select where column1 != column2, hence returning the rows with all the data needed. But alas, it was not long after coming up with this that I discover DB2 doesn't support pivot / unpivot...
Question
So is there any idea for how to accomplish this in DB2, taking a table with 80+ columns and two rows like so:
| Col A | Col B | Col C | ... | Col Z|
| ----- | ----- | ----- | --- | ---- |
| Val A | Val B | 123 | ... | 01/01/2021 |
| Val C | Val B | 124 | ... | 02/01/2021 |
And returning a table with the columns changed, their initial value, and their new value:
| Initial | New | ColName|
| ----- | ----- | ----- |
| Val A | Val C | Col A |
| 123 | 124 | Col C |
| 01/01/2021 | 02/01/2021 | Col Z |
Also note the column data types also vary, so will need to be converted to varchar
DB2 version is 11.1
EDIT: Also for reference as per comment request, this is code I attempted to use to achieve this goal:
WITH
INIT AS (SELECT * FROM TABLE WHERE SOMEDATE=(SELECT MIN(SOMEDATE) FROM TABLE),
LATE AS (SELECT * FROM TABLE WHERE SOMEDATE=(SELECT MAX(SOMEDATE) FROM TABLE),
COLS AS (SELECT COLNAME FROM SYSCAT.COLUMNS WHERE TABNAME='TABLE' ORDER BY COLNO)
SELECT * FROM (
SELECT
COLNAME AS ATTRIBUTE,
(SELECT COLNAME AS INITIAL FROM INIT),
(SELECT COLNAME AS NEW FROM LATE)
FROM
COLS
WHERE
(INITIAL != NEW) OR (INITIAL IS NULL AND NEW IS NOT NULL) OR (INITIAL IS NOT NULL AND NEW IS NULL));
Only issue with this one is that I couldn't figure how to use the values from the COLS table as the columns to be selected
You may easily generate text of the expressions needed, if you don't want to type them manually.
Consider the following example, if you want to print different column values only in 2 rows of the same quite a wide table SYSCAT.TABLES. We use the following query for such an expression generation.
SELECT
'DECODE(I.I, '
|| LISTAGG(COLNO || ', A.' || COLNAME || CASE WHEN TYPENAME NOT LIKE '%CHAR%' AND TYPENAME NOT LIKE '%GRAPHIC' THEN '::VARCHAR(128)' ELSE '' END, ', ')
|| ') AS INITIAL' AS EXPR_INITIAL
, 'DECODE(I.I, '
|| LISTAGG(COLNO || ', B.' || COLNAME || CASE WHEN TYPENAME NOT LIKE '%CHAR%' AND TYPENAME NOT LIKE '%GRAPHIC' THEN '::VARCHAR(128)' ELSE '' END, ', ')
|| ') AS NEW' AS EXPR_NEW
, 'DECODE(I.I, '
|| LISTAGG(COLNO || ', ''' || COLNAME || '''', ', ')
|| ') AS COLNAME' AS EXPR_COLNAME
FROM SYSCAT.COLUMNS C
WHERE TABSCHEMA = 'SYSCAT' AND TABNAME = 'TABLES'
AND TYPENAME NOT LIKE '%LOB';
It doesn't matter how many columns the table contains. We just filter out the columns of *LOB types as an example. If you want them as well, you should change the ::VARCHAR(128) casting to some ::CLOB(XXX).
These 3 generated expressions we put to the corresponding places in the query below:
WITH MYTAB AS
(
-- We enumerate the rows to reference them later
SELECT ROWNUMBER() OVER () RN_, T.*
FROM SYSCAT.TABLES T
WHERE TABSCHEMA = 'SYSCAT'
FETCH FIRST 2 ROWS ONLY
)
SELECT *
FROM
(
SELECT
-- Place here the result got in the EXPR_INITIAL column
-- , Place here the result got in the EXPR_NEW column
-- , Place here the result got in the EXPR_COLNAME column
FROM MYTAB A, MYTAB B
,
(
SELECT COLNO AS I
FROM SYSCAT.COLUMNS
WHERE TABSCHEMA = 'SYSCAT' AND TABNAME = 'TABLES'
AND TYPENAME NOT LIKE '%LOB'
) I
WHERE A.RN_ = 1 AND B.RN_ = 2
)
WHERE INITIAL IS DISTINCT FROM NEW;
The result I got in my database:
|INITIAL |NEW |COLNAME |
|--------------------------|--------------------------|---------------|
|2019-06-04-22.44.14.493001|2019-06-04-22.44.14.502001|ALTER_TIME |
|26 |15 |COLCOUNT |
|2019-06-04-22.44.14.493001|2019-06-04-22.44.14.502001|CREATE_TIME |
|2019-06-04-22.44.14.493001|2019-06-04-22.44.14.502001|INVALIDATE_TIME|
|2019-06-04-22.44.14.493001|2019-06-04-22.44.14.502001|LAST_REGEN_TIME|
|ATTRIBUTES |AUDITPOLICIES |TABNAME |
I have a rather tricky database problem that has really stumped me, would appreciate any help.
I have a table which includes data from multiple different sources. This data from different sources can be ‘duplicated’ and we have ways of identifying if that is the case.
Each row in the table has an ‘id’, and if it is identified as a duplicate of another row then we merge it, and it is given a ‘merged_into_id’ which refers to another row in the same table.
I am trying to run a report which will return information about where we have identified duplicates from two of those different sources.
Lets say I have three sources: A, B and C. I want to identify all of the duplicate rows between source A and source B.
I have got the query working fine to do this if a row from source A is directly merged into source B. However, we also have instances in the DB where source A row AND source B row are merged into source C. I am struggling with these and was hoping someone could help with that.
An example:
Original DB:
id
source
merged_into_id
1
A
3
2
B
3
3
C
NULL
What I would like to do is to be able to return id 1 and id 2 from that table, as they are both merged into the same ID e.g. like so:
source_a_id
source_b_id
1
2
But I'm really struggling to get to that - all I've managed to do is create a parent and child link like the following:
parent_id
child_id
child_source
3
1
A
3
2
B
I can also return just the IDs that I want, but they don't 'join' so to speak:
e.g.
SELECT
CASE WHEN child_source = 'A' then child_id as source_a_id,
CASE WHEN child_source = 'B' then child_id as source_b_id
But that just gives me a response with an empty row for the 'missing' data
---EDIT---
Using array_agg and array_to_string I've gotten a little closer to what I need:
SELECT
parent.id as parent_id,
ARRAY_TO_STRING(
ARRAY_AGG(CASE WHEN child_source = 'A' THEN child.id END)
, ','
) a_id,
ARRAY_TO_STRING(
ARRAY_AGG(CASE WHEN child_source = 'B' THEN child.id END)
, ','
) b_id
but its not quite the right format as I can occasionally have multiple versions from each source, so I get a table that looks like :
parent_id
a_id
b_id
3
1
2,4,5
In this case, I want to return a table that looks like:
parent_id
a_id
b_id
3
1
2
3
1
4
3
1
5
Does anyone have any advice on getting to my desired output? Many thanks
Suppose that we have this table
select * from t;
id | source | merged_into_id
----+--------+----------------
1 | A | 3
2 | B | 3
3 | C |
5 | B | 3
4 | B | 3
(5 rows)
This should do the work
WITH B_source as (select * from t where source = 'B'),
A_source as (select * from t where source = 'A')
SELECT merged_into_id,A_source.id as a_id,B_source.id as b_id
FROM A_source
INNER JOIN B_source using (merged_into_id);
Result
merged_into_id | a_id | b_id
----------------+------+------
3 | 1 | 2
3 | 1 | 5
3 | 1 | 4
(3 rows)
I have a function test_func() that takes in 1 argument (let's say the argument name is X) and returns a table. Now, I have a list of inputs (from a subquery) that I want to pass into argument X and collect all the results of the calls in a table.
In Python, I would do something like
# create empty list
all_results = []
for argument in (1,2,3):
result = test_func(argument)
# Collect the result
all_results.append(result)
return all_results
How can I do the same thing in postgresql?
Thank you.
For the sake of example, my test_func(X) takes in 1 argument and spits out a table with 3 columns. The values for col1 is X, col2 is X+1 and col3 is X+3. For example:
select * from test_func(1)
gives
|col1|col2|col3|
----------------
| 1 | 2 | 3 |
----------------
My list of arguments would be results of a subquery, for example:
select * from (values (1), (2)) x
I expect something like:
|col1|col2|col3|
----------------
| 1 | 2 | 3 |
----------------
| 2 | 3 | 4 |
----------------
demo:db<>fiddle
This gives you a result list of all results:
SELECT
mt.my_data as input,
tf.*
FROM
(SELECT * FROM my_table) mt, -- input data from a subquery
test_func(my_data) tf -- calling every data set as argument
In the fiddle the test_func() gets an integer and generates rows (input argument = generated row count). Furthermore, it adds a text column. For all inputs all generated records are unioned into one result set.
You can join your function to the input values:
select f.*
from (
values (1), (2)
) as x(id)
cross join lateral test_func(x.id) as f;
I have a table with a number of columns:
col1
col2
col3
coln....
I need to generate dynamic UPDATE statement like below which will be used in production for bulk update:
UPDATE TableA
SET TableA.ColA = ValueOfCol2
WHERE
TableA.ColB='A'
Could anyone please share a TSQL script that generate n number of UPDATE statement as above, please?
Thank you
Unless I'm misunderstanding your problem, your example code works:
UPDATE [updateDemo] SET [updateDemo].[col2] = [updateDemo].[col3] WHERE [col4] = 'A'
This is based on the assumption that your table is something like this:
col1 | col2 | col3 | col4
1 P Z A
2 Y Z A
3 K S V
This above update query would result in (changes in square brackets):
col1 | col2 | col3 | col4
1 [Z] Z A
2 [Z] Z A
3 K S V