I am updating a table, but I keep getting follwing error
ERROR: syntax error at or near "MERGE"
LINE 3: MERGE into
when i try to use a merge statement. I don't see anything obvious wrong with the syntax. can someone point out the obivous
MERGE into Table2 t2
using (select name, max(id) max_id from Table1 t1 group by name ) t1
on (t2.project_name=t1.name)
when matched then update set projectid=max_id where status='ongoing' ;
Table1
1 | alpha | 2021 |
2 | groundwork | 2020 |
3 | NETOS | 2021 |
5 | WebOPD | 2019 |
Table2
id | name | year | status | project name | projectID
1 | john | 2021 | ongoing | alpha | 1
2 | linda | 2021 | completed | NETOS | 3
3 | pat | 2021 | WebOPD | completed | 5
4 | tom | 2021 | ongoing | alpha | 1
version : PostgreSQL 13.6
The last line in your message says you use PostgreSQL. Tag you used (plsql) means Oracle. Which one is it, after all? I presume former, but - syntax you used is Oracle.
MERGE documentation for PostgreSQL says that
INTO can't be used
no parenthesis for ON clause
WHERE clause can't be used
See if something like this helps:
MERGE Table2 t2
using (select t1.name,
max(t1.id) max_id
from Table1 t1 join table2 t2 on t2.project_name = t1.name
where t2.status = 'ongoing'
group by name
) x
on t2.project_name = x.name
when matched then update set
t2.projectid = x.max_id ;
Related
I've a SQLite database table with the following columns:
| day | place | visitors |
-------------------------------------
| 2021-05-01 | AAA | 20 |
| 2021-05-01 | BBB | 10 |
| 2021-05-01 | CCC | 3 |
| 2021-05-02 | AAA | 5 |
| 2021-05-02 | BBB | 7 |
| 2021-05-02 | CCC | 2 |
Now I would like to introduce a column 'rank' which indicates the rank according to the visitors each day. Expected table would look like:
| day | place | visitors | Rank |
------------------------------------------
| 2021-05-01 | AAA | 20 | 1 |
| 2021-05-01 | BBB | 10 | 2 |
| 2021-05-01 | CCC | 3 | 3 |
| 2021-05-02 | AAA | 5 | 2 |
| 2021-05-02 | BBB | 7 | 1 |
| 2021-05-02 | CCC | 2 | 3 |
Populating the data for the new column Rank can be done with a program like (Pseudocode).
for each i_day in all_days:
SELECT
ROW_NUMBER () OVER (ORDER BY `visitors` DESC) Day_Rank, place
FROM mytable
WHERE `day` = 'i_day'
for each i_place in all_places:
UPDATE mytable
SET rank= Day_Rank
WHERE `Day`='i_day'
AND place = 'i_place'
Since this line by line update is quite inefficient, I'm searching how to optimize this with a SQL sub query in combination with the UPDATE.
(does not work so far...)
for each i_day in all_days:
UPDATE mytable
SET rank= (
SELECT
ROW_NUMBER () OVER (ORDER BY `visitors` DESC) Day_Rank
FROM mytable
WHERE `day` = 'i_day'
)
Typically, this can be done with a subquery that counts the number of rows with visitors greater than the value of visitors of the current row:
UPDATE mytable
SET Day_Rank = (
SELECT COUNT(*) + 1
FROM mytable m
WHERE m.day = mytable.day AND m.visitors > mytable.visitors
);
Note that the result is actually what RANK() would return, if there are ties in the values of visitors.
See the demo.
Or, you could calculate the rankings with ROW_NUMBER() in a CTE and use it in a subquery:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY day ORDER BY visitors DESC) rn
FROM mytable
)
UPDATE mytable
SET Day_Rank = (SELECT rn FROM cte c WHERE (c.day, c.place) = (mytable.day, mytable.place));
See the demo.
Or, if your versipn of SQLite is 3.33.0+ you can use the join-like UPDATE...FROM... syntax:
UPDATE mytable AS m
SET Day_Rank = t.rn
FROM (
SELECT *, ROW_NUMBER() OVER (PARTITION BY day ORDER BY visitors DESC) rn
FROM mytable
) t
WHERE (t.day, t.place) = (m.day, m.place);
I have two tables in a SQLite db like so
| t1 |
|===============|
| t1_id | other |
|-------|-------|
| 1 | sdfds |
| 2 | asdaa |
| 3 | lkjeq |
| t2 |
|=======================|
| t2_id | t1_id | other |
|-------|-------|-------|
| 1 | 1 | dggeh |
| 2 | 1 | iohio |
| 3 | 3 | ytucc |
| 4 | 3 | .noih |
| 5 | 3 | /oioi |
There are approx. 300K+ rows in both tables. I want the counts of t1 that have related rows in t2 as well as those that don't have. That is,
"count of t1 with related t2" : 2
"count of t1 with no related t2": 1
Of course, I can get "count of t1 with related t2" from
SELECT Count(*) FROM t1 JOIN t2 ON t1.t1_id = t2.t1_id;
and the "count of t1 with no related t2" by subtracting the above from the total count of t1. But how can I get it from a SQL query efficiently? I tried the following
EXPLAIN QUERY PLAN SELECT t1_id FROM t1 AS t
WHERE NOT EXISTS (SELECT * FROM t2 WHERE t.t1_id = t2.t1_id);
and I see that the index on t1_id in table t2 is not used. When I try the query, it takes really long, like 100s of seconds.
A couple of possibilities:
SELECT count(*) FROM
(SELECT t1_id FROM t1
EXCEPT
SELECT t1_id FROM t2);
or
SELECT count(*)
FROM t1
WHERE t1_id NOT IN (SELECT t1_id FROM t2);
or (A slight variation on your original):
SELECT count(*)
FROM t1
WHERE NOT EXISTS (SELECT 1 FROM t2 WHERE t1.t1_id = t2.t1_id);
All three of those should use an index on t2(t1_idx). You'll have to do benchmarking on real data to see which is faster.
I am trying to update Data1's ID to Record2's ID when:
Record1's and Record2's Name are the same, and
Weight is greater in Record2.
Record1
| ID | Weight | Name |
|----|--------|------|
| 1 | 10 | a |
| 2 | 10 | b |
| 3 | 10 | c |
Record2
| ID | Weight | Name |
|----|--------|------|
| 4 | 20 | a |
| 5 | 20 | b |
| 6 | 20 | c |
Data1
| ID | Weight |
|----|--------|
| 4 | 40 |
| 5 | 40 |
I have tried the following SQLite query:
update data1
set id =
(select record2.id
from record2,record1
where record1.name=record2.name
and record1.weight<record2.weight)
where id in
(select record1.id
from record1, record2
where record1.name=record2.name
and record1.weight<record2.weight)
Using the above query Data1's id is updated to 4 for all records.
NOTE: Record1's ID is the foreign key for Data1.
For the given data set the following seems to serve the cause:
update data1
set id =
(select record2.id
from record2,record1
where
data1.id = record1.id
and record1.name=record2.name
and record1.weight<record2.weight)
where id in
(select record1.id
from record1, record2
where
record1.id in (select id from data1)
and record1.name=record2.name
and record1.weight<record2.weight)
;
See it in action: SQL Fiddle.
Please comment if and as this requires adjustment / further detail.
I have 3 sqlite tables:
table inspections, where insp_id is primary key
id | name | deleted
------------------------------
I1 | Inspection A | (null)
I2 | Inspection B | (null)
I3 | Inspection C | 1
table equip_insp, where equip_id, insp_id are primary keys
equip_id | insp_id | period | period_type
--------------------------------------------
E1 | I1 | 1 | Y
E1 | I2 | 6 | M
E2 | I1 | 1 | M
table equip_certif, where id is primary key
id | equip_id | insp_id | date | certif_no | result | info
-------------------------------------------------------------------
C4 | E1 | I1 | 2015-02-01 | A-300 | Good | (null)
C3 | E1 | I1 | 2015-02-01 | A-200 | Good | (null)
C2 | E1 | I1 | 2015-01-10 | A-100 | Good | (null)
C1 | E1 | I2 | 2015-01-06 | B-100 | Good | (null)
All ID's are in fact numeric values, I use some letters just to be easy to connect them in between.
So, I would like help me with the Sqlite syntax that for item E1, display all the inspection defined (ascending), then if exist, to display the periodicity and then to display the latest certificate date (if there are 2 certificates in the same date, get the latest id), number and result that is not info
Result should be something like this:
id | name | period | period_type | certif_no | date | result
--------------------------------------------------------------------------
I1 | Inspection A | 1 | Y | A-300 | 2015-02-01 | Good
I2 | Inspection B | 6 | M | B-100 | 2015-01-06 | Good
I've try this, but I'm not so sure that is correct.
SELECT inspections.id, inspections.name, equip_insp.period, equip_insp.period_type, equip_certif.certif_no, equip_certif.date AS certif_date, equip_certif.result
FROM inspections
LEFT JOIN equip_insp ON (inspections.id = equip_insp.insp_id AND equip_insp.equip_id = 'E1')
LEFT JOIN equip_certif ON (inspections.id = equip_certif.insp_id AND equip_certif.info IS NULL)
WHERE inspections.deleted IS NULL
GROUP BY equip_insp.insp_id
ORDER BY inspections.id, date(equip_certif.date) DESC, equip_certif.id DESC
To specifiy which row from a group gets returned, you must use MAX(); otherwise, you get some randrom row:
SELECT ..., MAX(equip_certif.date) AS certif_date, ...
FROM ...
GROUP BY equip_insp.insp_id
...
(This works only in SQLite 3.7.11 or later; in earlier version, the query would get more complex.)
After playing with SQLite I get the solution by myself. So the answer is:
SELECT inspections.id, inspections.name, equip_insp.period, equip_insp.period_type, equip_certif.certif_no, equip_certif.date AS certif_date, equip_certif.result
FROM inspections
LEFT JOIN equip_insp ON (inspections.id = equip_insp.insp_id AND equip_insp.equip_id = 'E1')
LEFT JOIN equip_certif ON (inspections.id = equip_certif.insp_id AND equip_certif.equip_id = equip_insp.equip_id AND equip_certif.info IS NULL)
WHERE inspections.deleted IS NULL
GROUP BY inspections.id
ORDER BY inspections.id, date(equip_certif.date) DESC, equip_certif.id DESC
I've this two tables, members and water_meter
members
id | name
=========
1 | Dani
2 | Dina
3 | Roni
water_meter
id | member_id | date | start | finish | paid | paid_at
===+============+===========+=======+===========+=======+=====================+
1 | 1 |2014-07-01 | 12.3 | 38.7 | 1 | 2014-12-29 18:28:30
2 | 2 |2014-07-01 | 57.2 | 64.3 | 0 | null
3 | 3 |2014-07-01 | 14.6 | 52.3 | 0 | null
This member need to pay their water usage every month. What I want is, the 'start' value of each month is the 'finish' value from previous months. This is my query to check water usage at August,
SELECT m.id, m.name,
ifnull(t.start, (SELECT ifnull(finish, 0) FROM members m2
LEFT JOIN water_meter t2 ON m2.id = t2.member_id AND t2.date = '2014-07-01') ) as start,
t.finish, paid
FROM members m
LEFT JOIN water_meter t ON m.id = t.member_id AND t.date = '2014-08-01'
Result :
id | name | start | finish |
===+========+========+=========+
1 | Dani | 38.7 | null |
2 | Dina | 38.7 | null |
3 | Roni | 38.7 | null |
As you can see, the "start" value is not right. What is the right query for this case?
What I want is like this
id | name | start | finish |
===+========+========+=========+
1 | Dani | 38.7 | null |
2 | Dina | 64.3 | null |
3 | Roni | 52.3 | null |
Check : http://sqlfiddle.com/#!7/29a4c/2
You haven't assigned correct where condition in inner query.
SELECT m.id, m.name,
ifnull(t.start,
(SELECT ifnull(finish, 0) FROM members m2
LEFT JOIN water_meter t2
ON m2.id = t2.member_id AND t2.date = '2014-07-01'
where m2.id = m.id)) as start,
t.finish, paid
FROM members m
LEFT JOIN water_meter t ON m.id = t.member_id AND t.date = '2014-08-01'
WHERE m.active = 1
I don't like query itself, but that produces the output you wanted.
A little better (no subqueries, which may be slow on large dataset) solution:
select
members.id,
name,
coalesce(wm_cur.start, wm_prev.finish),
wm_cur.finish
from members
left join water_meter wm_cur
on members.id = wm_cur.member_id
and wm_cur.date between '2014-08-01' and date('2014-08-01','start of month','+1 month','-1 day')
left join water_meter wm_prev
on members.id = wm_prev.member_id
and wm_prev.date between '2014-07-01' and date('2014-07-01','start of month','+1 month','-1 day')
where members.active = 1
You can replace coalesce with ifnull if you wish. It also handles entire month and not only first day, which may or may not be what you want it to be.