When I'm running a COPY my_table FROM 'my_table_source.csv' WITH HEADER CSV; is it possible to extract the row number within the csv file and add that information into my target table? I have some flat files coming from external sources and going to multiple databases that would be useful to trace backwards during occasional audits done down the road. Thanks.
Add column names and omit the name of the serial:
CREATE TEMP TABLE passwords (
seq serial not null PRIMARY KEY
, name text
, passwd text
, uid integer not null
, gid integer not null
, gcos text
, home text
, shell text
);
COPY passwords(name,passwd,uid,gid,gcos,home,shell)
FROM '/etc/passwd' WITH csv DELIMITER ':' ;
SELECT * FROM passwords
WHERE seq < 10
;
Output:
CREATE TABLE
COPY 48
seq | name | passwd | uid | gid | gcos | home | shell
-----+--------+--------+-----+-------+--------+----------------+-------------------
1 | root | x | 0 | 0 | root | /root | /bin/bash
2 | daemon | x | 1 | 1 | daemon | /usr/sbin | /usr/sbin/nologin
3 | bin | x | 2 | 2 | bin | /bin | /usr/sbin/nologin
4 | sys | x | 3 | 3 | sys | /dev | /usr/sbin/nologin
5 | sync | x | 4 | 65534 | sync | /bin | /bin/sync
6 | games | x | 5 | 60 | games | /usr/games | /usr/sbin/nologin
7 | man | x | 6 | 12 | man | /var/cache/man | /usr/sbin/nologin
8 | lp | x | 7 | 7 | lp | /var/spool/lpd | /usr/sbin/nologin
9 | mail | x | 8 | 8 | mail | /var/mail | /usr/sbin/nologin
(9 rows)
Related
I am a novice self-teaching Microsoft Access.
I have an MS Access database with a table of students (Table1).
Table1
+----+-----------+----------+------------+------------+
| id | firstname | lastname | Year_Group | Form_Group |
+----+-----------+----------+------------+------------+
| 2 | mnb | nbgfv | 7 | 1 |
| 3 | jhg | uhgf | 8 | 2 |
| 4 | poi | ijuy | 9 | 2 |
| 5 | tgf | tgfd | 10 | 2 |
| 6 | wer | qwes | 11 | 2 |
+----+-----------+----------+------------+------------+
Every day students days are recorded sort of like Table2.
Table2
+----------+----+-----------+----------+------------+--------+-----------+----------+
| Date | id | firstname | lastname | Year_Group | Effort | Behaviour | Homework |
+----------+----+-----------+----------+------------+--------+-----------+----------+
| 28/02/19 | 2 | mnb | nbgfv | 7 | Good | Good | Y |
| 28/02/19 | 3 | jhg | uhgf | 8 | OK | OK | Y |
| 28/02/19 | 4 | poi | ijuy | 9 | Bad | Bad | N |
| 01/03/19 | 5 | tgf | tgfd | 10 | Good | OK | Y |
| 01/03/19 | 6 | wer | qwes | 11 | Good | Good | Y |
+----------+----+-----------+----------+------------+--------+-----------+----------+
Is there a way (when using a list box or combo box) to select a student from Table1 so that their information is used for the corresponding columns in Table2?
Or is there a more efficient way to do this?
Firstly, you should normalise your data.
Currently, you are repeating the firstname, lastname, and Year_Group data in two separate tables, which not only bloats your database, but also means that such data must be maintained in two separate places, potentially leading to inconsistencies and then uncertainty as to which is the master.
Instead, I would suggest that your Students table should contain all information pertaining to the characteristics of a student:
Students
+----+-----------+----------+------------+------------+
| id | firstname | lastname | Year_Group | Form_Group |
+----+-----------+----------+------------+------------+
| 2 | mnb | nbgfv | 7 | 1 |
| 3 | jhg | uhgf | 8 | 2 |
| 4 | poi | ijuy | 9 | 2 |
| 5 | tgf | tgfd | 10 | 2 |
| 6 | wer | qwes | 11 | 2 |
+----+-----------+----------+------------+------------+
And the information pertaining to each school day should only reference the student ID in the Students table:
SchoolDays
+----------+----+--------+-----------+----------+
| Date | id | Effort | Behaviour | Homework |
+----------+----+--------+-----------+----------+
| 28/02/19 | 2 | Good | Good | Y |
| 28/02/19 | 3 | OK | OK | Y |
| 28/02/19 | 4 | Bad | Bad | N |
| 01/03/19 | 5 | Good | OK | Y |
| 01/03/19 | 6 | Good | Good | Y |
+----------+----+--------+-----------+----------+
Then, if you want to display the data in its entirety, you would use a query which joins the two tables, e.g.:
select
t2.date,
t1.firstname,
t1.lastname,
t1.year_group,
t2.effort,
t2.behaviour,
t2.homework
from
students t1 inner join schooldays t2 on t1.id = t2.id
I need help with updating table from another table in Postgres Db.
Long story short we ended up with corrupted data in db, and now I need to update one table with values from another.
I have table with this data table wfc:
| step_id | command_id | commands_order |
|---------|------------|----------------|
| 1 | 1 | 0 |
| 1 | 2 | 1 |
| 1 | 3 | 2 |
| 1 | 4 | 3 |
| 1 | 1 | 0 |
| 2 | 2 | 0 |
| 2 | 3 | 1 |
| 2 | 3 | 1 |
| 2 | 4 | 3 |
and I want to update values in command_order column from another table, so I can have result like this:
| step_id | command_id | commands_order|
|---------|------------|---------------|
| 1 | 1 | 0 |
| 1 | 2 | 1 |
| 1 | 3 | 2 |
| 1 | 4 | 3 |
| 1 | 1 | 4 |
| 2 | 2 | 0 |
| 2 | 3 | 1 |
| 2 | 3 | 2 |
| 2 | 4 | 3 |
It was looking like easy task, but problem is to update rows for same command_id, it is writing same value in commands_order
SQL that I tried is:
UPDATE wfc
SET commands_order = CAST(sq.input_step_id as INTEGER)
FROM (
SELECT wfp.step_id, wfp.input_command_id, wfp.input_step_id
from wfp
order by wfp.step_id, wfp.input_step_id
) AS sq
WHERE (wfc.step_id=sq.step_id AND wfc.command_id=CAST(sq.input_command_id as INTEGER));
SQL Fiddle http://sqlfiddle.com/#!15/4efff4/4
I am pretty stuck with this, please help.
Thanks in advance.
Assuming you are trying to number the rows in the order in which they were created, and as long as you understand that ctid will chnage on update and with VACCUUM FULL, you can do the following:
select step_id, command_id, rank - 1 as command_order
from (select step_id, command_id, ctid as wfc_ctid, rank() over
(partition by step_id order by ctid)
from wfc) as wfc_ordered;
This will give you the wfc table with the ordering that you want. If you do update the original table, the ctids will change, so it's probably safer to create a copy of the table with the above query.
I am having a hard time trying to wrap my head around the pivot/unpivot concepts and hoping someone can help or give me some guidance on how to approach my problem.
Here is a simplified sample table I have
+-------+------+------+------+------+------+
| SAUID | COM1 | COM2 | COM3 | COM4 | COM5 |
+-------+------+------+------+------+------+
| 1 | 24 | 22 | 100 | 0 | 45 |
| 2 | 34 | 55 | 789 | 23 | 0 |
| 3 | 33 | 99 | 5552 | 35 | 4675 |
+-------+------+------+------+------+------+
The end result I am looking for a table result similar below
+-------+-----------+-------+
| SAUID | OCCUPANCY | VALUE |
+-------+-----------+-------+
| 1 | COM1 | 24 |
| 1 | COM2 | 22 |
| 1 | COM3 | 100 |
| 1 | COM4 | 0 |
| 1 | COM5 | 45 |
| 2 | COM1 | 34 |
| 2 | COM2 | 55 |
| 2 | COM3 | 789 |
| 2 | COM4 | 23 |
| 2 | COM5 | 0 |
| 3 | COM1 | 33 |
| 3 | COM2 | 99 |
| 3 | COM3 | 5552 |
| 3 | COM4 | 35 |
| 3 | COM5 | 4675 |
+-------+-----------+-------+
Im looking around but most of the examples seem to use pivot but having a hard time trying to wrap that around my case as I need the values all in one column.
I hoping to experiment with some hardcoding to get fimilar with my example but my actual table columns are ~100 with varying #s of SAUID per table and looks like it will require dynamic sql?
Thanks for the help in advance.
Use UNPIVOT:
SELECT u.SAUID, u.OCCUPANCY, u.VALUE
FROM yourTable t
UNPIVOT
(
VALUE for OCCUPANCY in (COM1, COM2, COM3, COM4, COM5)
) u;
ORDER BY
u.SAUID, u.OCCUPANCY;
Demo
In this answer to the question Right query to get the current number of connections in a PostgreSQL DB the poster implies that
SELECT sum(numbackends) FROM pg_stat_database;
and
SELECT count(*) FROM pg_stat_activity;
give the same results.
However, if I do this on my db the first one says 119 and the second one 30.
This is the difference as shown by summing numbackends and counting:
+------+-------------+-------+
| | numbackends | count |
+------+-------------+-------+
| db1 | 1 | 1 |
| db2 | 1 | 1 |
| db3 | 1 | 1 |
| db4 | 1 | 1 |
| db5 | 2 | 2 |
| db6 | 2 | 2 |
| db7 | 12 | 3 | <--
| db8 | 4 | 4 |
| db9 | 5 | 5 |
| db10 | 78 | 35 | <--
+------+-------------+-------+
Why does this difference exist?
How can I list each of the 119-30=89 backends not shown in pg_stat_activity?
I have two subqueries. Here is the output of subquery A....
id | date_lat_lng | stat_total | rnum
-------+--------------------+------------+------
16820 | 2016_10_05_10_3802 | 9 | 2
15701 | 2016_10_05_10_3802 | 9 | 3
16821 | 2016_10_05_11_3802 | 16 | 2
17861 | 2016_10_05_11_3802 | 16 | 3
16840 | 2016_10_05_12_3683 | 42 | 2
17831 | 2016_10_05_12_3767 | 0 | 2
17862 | 2016_10_05_12_3802 | 11 | 2
17888 | 2016_10_05_13_3683 | 35 | 2
17833 | 2016_10_05_13_3767 | 24 | 2
16823 | 2016_10_05_13_3802 | 24 | 2
and subquery B, in which date_lat_lng and stat_total has commonality with subquery A, but id does not.
id | date_lat_lng | stat_total | rnum
-------+--------------------+------------+------
17860 | 2016_10_05_10_3802 | 9 | 1
15702 | 2016_10_05_11_3802 | 16 | 1
17887 | 2016_10_05_12_3683 | 42 | 1
15630 | 2016_10_05_12_3767 | 20 | 1
16822 | 2016_10_05_12_3802 | 20 | 1
16841 | 2016_10_05_13_3683 | 35 | 1
15632 | 2016_10_05_13_3767 | 23 | 1
17863 | 2016_10_05_13_3802 | 3 | 1
16842 | 2016_10_05_14_3683 | 32 | 1
15633 | 2016_10_05_14_3767 | 12 | 1
Both subquery A and B pull data from the same table. I want to delete the rows in that table that share the same ID as subquery A but only where date_lat_lng and stat_total have a shared match in subquery B.
Effectively I need:
DELETE FROM table WHERE
id IN
(SELECT id FROM (subqueryA) WHERE
subqueryA.date_lat_lng=subqueryB.date_lat_lng
AND subqueryA.stat_total=subqueryB.stat_total)
Except I'm not sure where to place subquery B, or if I need an entirely different structure.
Something like this,
DELETE FROM table WHERE
id IN (
SELECT DISTINCT id
FROM subqueryA
JOIN subqueryB
USING (id,date_lat_lng,stat_total)
)