I have this query in postgresql:
select *
from A s
join B m on (s.id=m.id)
where m.key=4 and s.ran=some_input_from_user
This gives me all the rows that I need to update.
I want to set A.value to be 90 for all these rows.
It doesn't look like a standart update query
if I do...
Update A set value=90 where.....
then I can't do the join.
any ideas how to do it?
This is the basic update syntax for PostgreSQL where you are updating based on a join to another table:
update A s
set
value = 90
from B m
where
s.id = m.id and
m.key = 4 and
s.ran = some_input_from_user
The trick is you never use the alias in the lvalue for the set commands. In other words, value = 90 is not s.value = 90. It seems minor, but I'm pretty sure it will prevent your query from working. The rationale is if you are updating table A (alias s) then any fields you are updating are, de-facto, from table A -- no need to alias them, and to allow aliases would almost imply you could update something other than A with this statement, which you cannot.
You can definitely use them in the rvalues, so this would certainly be okay (if it were your desire to update A based on B):
update A s
set
value = m.salary * s.commission
from B m
where
s.id = m.id and
(s.value is null or
s.value != m.salary * s.commission)
Here is the query:
update a set value = 90
where exists (
select 1 from b
where a.id = b.id and b.key=4
and a.ran=some_input_from_user);
The above query will eliminate the requirement of reading table a twice.
Also you can use this query:
update a set value = 90
where a.id in
(select b.id from b
where a.id = b.id and b.key = 4
and a.ran=some_input_from_user);
TRY THIS
UPDATE A
SET A.VALUE = 90
from A
join B m on (A.id=m.id)
where m.key=4 and s.ran=some_input_from_user
Basically, I want to do this:
update vehicles_vehicle v
join shipments_shipment s on v.shipment_id=s.id
set v.price=s.price_per_vehicle;
I'm pretty sure that would work in MySQL (my background), but it doesn't seem to work in postgres. The error I get is:
ERROR: syntax error at or near "join"
LINE 1: update vehicles_vehicle v join shipments_shipment s on v.shi...
^
Surely there's an easy way to do this, but I can't find the proper syntax. So, how would I write this In PostgreSQL?
The UPDATE syntax is:
[ WITH [ RECURSIVE ] with_query [, ...] ]
UPDATE [ ONLY ] table [ [ AS ] alias ]
SET { column = { expression | DEFAULT } |
( column [, ...] ) = ( { expression | DEFAULT } [, ...] ) } [, ...]
[ FROM from_list ]
[ WHERE condition | WHERE CURRENT OF cursor_name ]
[ RETURNING * | output_expression [ [ AS ] output_name ] [, ...] ]
In your case I think you want this:
UPDATE vehicles_vehicle AS v
SET price = s.price_per_vehicle
FROM shipments_shipment AS s
WHERE v.shipment_id = s.id
Or if you need to join on two or more tables:
UPDATE table_1 t1
SET foo = 'new_value'
FROM table_2 t2
JOIN table_3 t3 ON t3.id = t2.t3_id
WHERE
t2.id = t1.t2_id
AND t3.bar = True;
The answer of Mark Byers is the optimal in this situation.
Though in more complex situations you can take the select query that returns rowids and calculated values and attach it to the update query like this:
with t as (
-- Any generic query which returns rowid and corresponding calculated values
select t1.id as rowid, f(t2, t2) as calculatedvalue
from table1 as t1
join table2 as t2 on t2.referenceid = t1.id
)
update table1
set value = t.calculatedvalue
from t
where id = t.rowid
This approach lets you develop and test your select query and in two steps convert it to the update query.
So in your case the result query will be:
with t as (
select v.id as rowid, s.price_per_vehicle as calculatedvalue
from vehicles_vehicle v
join shipments_shipment s on v.shipment_id = s.id
)
update vehicles_vehicle
set price = t.calculatedvalue
from t
where id = t.rowid
Note that column aliases are mandatory otherwise PostgreSQL will complain about the ambiguity of the column names.
Let me explain a little more by my example.
Task: correct info, where abiturients (students about to leave secondary school) have submitted applications to university earlier, than they got school certificates (yes, they got certificates earlier, than they were issued (by certificate date specified). So, we will increase application submit date to fit certificate issue date.
Thus. next MySQL-like statement:
UPDATE applications a
JOIN (
SELECT ap.id, ab.certificate_issued_at
FROM abiturients ab
JOIN applications ap
ON ab.id = ap.abiturient_id
WHERE ap.documents_taken_at::date < ab.certificate_issued_at
) b
ON a.id = b.id
SET a.documents_taken_at = b.certificate_issued_at;
Becomes PostgreSQL-like in such a way
UPDATE applications a
SET documents_taken_at = b.certificate_issued_at -- we can reference joined table here
FROM abiturients b -- joined table
WHERE
a.abiturient_id = b.id AND -- JOIN ON clause
a.documents_taken_at::date < b.certificate_issued_at -- Subquery WHERE
As you can see, original subquery JOIN's ON clause have become one of WHERE conditions, which is conjucted by AND with others, which have been moved from subquery with no changes. And there is no more need to JOIN table with itself (as it was in subquery).
For those actually wanting to do a JOIN you can also use:
UPDATE a
SET price = b_alias.unit_price
FROM a AS a_alias
LEFT JOIN b AS b_alias ON a_alias.b_fk = b_alias.id
WHERE a_alias.unit_name LIKE 'some_value'
AND a.id = a_alias.id;
You can use the a_alias in the SET section on the right of the equals sign if needed.
The fields on the left of the equals sign don't require a table reference as they are deemed to be from the original "a" table.
For those wanting to do a JOIN that updates ONLY the rows your join returns use:
UPDATE a
SET price = b_alias.unit_price
FROM a AS a_alias
LEFT JOIN b AS b_alias ON a_alias.b_fk = b_alias.id
WHERE a_alias.unit_name LIKE 'some_value'
AND a.id = a_alias.id
--the below line is critical for updating ONLY joined rows
AND a.pk_id = a_alias.pk_id;
This was mentioned above but only through a comment..Since it's critical to getting the correct result posting NEW answer that Works
Here we go:
update vehicles_vehicle v
set price=s.price_per_vehicle
from shipments_shipment s
where v.shipment_id=s.id;
Simple as I could make it.
To add something quite important to all the great answers above, when you want to update a join-table, you may have 2 problems:
you cannot use the table you want to update to JOIN another one
Postgres wants a ON clause after the JOIN so you cannot only use where clauses.
This means that basically, the following queries are not valid:
UPDATE join_a_b
SET count = 10
FROM a
JOIN b on b.id = join_a_b.b_id -- Not valid since join_a_b is used here
WHERE a.id = join_a_b.a_id
AND a.name = 'A'
AND b.name = 'B'
UPDATE join_a_b
SET count = 10
FROM a
JOIN b -- Not valid since there is no ON clause
WHERE a.id = join_a_b.a_id
AND b.id = join_a_b.b_id
a.name = 'A'
AND b.name = 'B'
Instead, you must use all the tables in the FROM clause like this:
UPDATE join_a_b
SET count = 10
FROM a, b
WHERE a.id = join_a_b.a_id
AND b.id = join_a_b.b_id
AND a.name = 'A'
AND b.name = 'B'
It might be straightforward for some but I got stuck on this problem wondering what's going on so hopefully, it will help others.
Here's a simple SQL that updates Mid_Name on the Name3 table using the Middle_Name field from Name:
update name3
set mid_name = name.middle_name
from name
where name3.person_id = name.person_id;
The link below has a example that resolve and helps understant better how use update and join with postgres.
UPDATE product
SET net_price = price - price * discount
FROM
product_segment
WHERE
product.segment_id = product_segment.id;
See: http://www.postgresqltutorial.com/postgresql-update-join/
First Table Name: tbl_table1 (tab1).
Second Table Name: tbl_table2 (tab2).
Set the tbl_table1's ac_status column to "INACTIVE"
update common.tbl_table1 as tab1
set ac_status= 'INACTIVE' --tbl_table1's "ac_status"
from common.tbl_table2 as tab2
where tab1.ref_id= '1111111'
and tab2.rel_type= 'CUSTOMER';
To UPDATE one Table using another, in PostGRE SQL / AWS (SQL workbench).
In PostGRE SQL, this is how you need to use joins in UPDATE Query:
UPDATE TABLEA set COLUMN_FROM_TABLEA = COLUMN_FROM_TABLEB FROM TABLEA,TABLEB WHERE FILTER_FROM_TABLEA = FILTER_FROM_TABLEB;
Example:
Update Employees Set Date_Of_Exit = Exit_Date_Recorded , Exit_Flg = 1 From Employees, Employee_Exit_Clearance Where Emp_ID = Exit_Emp_ID
Table A - Employees Columns in Table A - Date_Of_Exit,Emp_ID,Exit_Flg Table B is - Employee_Exit_Clearance Columns in Table B - Exit_Date_Recorded,Exit_Emp_ID
1760 rows affected
Execution time: 29.18s
--goal: update selected columns with join (postgres)--
UPDATE table1 t1
SET column1 = 'data'
FROM table1
RIGHT JOIN table2
ON table2.id = table1.id
WHERE t1.id IN
(SELECT table2.id FROM table2 WHERE table2.column2 = 12345)
The first way is slower than the second way.
First:
DO $$
DECLARE
page int := 10000;
min_id bigint; max_id bigint;
BEGIN
SELECT max(id),min(id) INTO max_id,min_id FROM opportunities;
FOR j IN min_id..max_id BY page LOOP
UPDATE opportunities SET sec_type = 'Unsec'
FROM opportunities AS opp
INNER JOIN accounts AS acc
ON opp.account_id = acc.id
WHERE acc.borrower = true
AND opp.sec_type IS NULL
AND opp.id >= j AND opp.id < j+page;
COMMIT;
END LOOP;
END; $$;
Second:
DO $$
DECLARE
page int := 10000;
min_id bigint; max_id bigint;
BEGIN
SELECT max(id),min(id) INTO max_id,min_id FROM opportunities;
FOR j IN min_id..max_id BY page LOOP
UPDATE opportunities AS opp
SET sec_type = 'Unsec'
FROM accounts AS acc
WHERE opp.account_id = acc.id
AND opp.sec_type IS NULL
AND acc.borrower = true
AND opp.id >= j AND opp.id < j+page;
COMMIT;
END LOOP;
END; $$;
WORKS PERFECT!!!
POSTGRE SQL - UPDATE With a JOIN
BELOW CODE - Check the positioning of columns and IDs as below:
If you place it exactly as below, then only it will work!
---IF you want to update FIRST table
UPDATE table1
SET attribute1 = table2.attribute1
FROM table2
WHERE table2.product_ID = table1.product_ID;
OR
---IF you want to update SECOND table
UPDATE table2
SET attribute1 = table1.attribute1
FROM table1
WHERE table1.product_ID = table2.product_ID;
basically I have 2 tables, tableA and tableB. For simple example sake, both tables have the same int columns. MyInt1 and MyInt2. Well what I want to do is this.
When MyInt2 is null, i just want to join tableA to tableB on tableA.MyInt1 = tableB.MyInt1
when MyInt2 is not null, I want to join it like this tableA.MyInt1 = tableB.MyInt1 and tableA.MyInt2 = tableB.MyInt2
One way is to use a complicated case statement:
on 1 = (case when tableA.MyInt1 is not null or tableB.MyInt1 is not null and
tableA.MyInt1 = tableB.MyInt1
then 1
when tableA.MyInt2 = tableB.MyInt2
then 1
end)
EDIT:
In practice, I'd be inclined to split this into two joins and use coalesce() to prioritize in the select:
select a.*, coalesce(b1.col, b2.col)
from tableA a left join
tableB b1
on a.MyInt1 = b1.MyInt1 left join
tableB b2
on a.MyInt2 = b2.MyInt2;
This will not always work -- for instance, there are unexpected results if there is more than one match in tableB. But, this structure works better because it is easier to optimize.
I have two statements that I want to merge into one output.
Statement One:
select name from auxiliary_variable_inquiry
where inquiry_idbr_code = '063'
Returns the following list of names:
Name
------------
Affiliates
NetBookValue
Parents
Worldbase
Statement Two:
select name, value from auxiliary_variable_value
where inquiry_idbr_code = '063'
and ru_ref = 20120000008
and period = 200912
Returns the following:
Name Value
-------------------
Affiliates 112
NetBookValue 225.700
I would like to have an output like this:
Name Value
-------------------
Affiliates 112
NetBookValue 225.700
Parents 0
Worldbase 0
So basically, if the second query only returns 2 names and values, I'd still like to display the complete set of names from the first query, with no values. If all four values were returned by both queries, then all four would be displayed.
Sorry I must add, im using Ingres SQL so im unable to use the ISNULL function.
You can do a left join. This ensures that all records from the first table will stay included. Where value is null, no child record was found, and we use coalesce to display 0 in these cases.
select i.name, COALESCE(v.Value,0) from auxiliary_variable_inquiry i
left join auxiliary_variable_value v
on v.inquiry_idbr_code = i.inquiry_idbr_code
and v.ru_ref = 20120000008
and v.period = 200912
where i.inquiry_idbr_code = '063'
I'd recommend a self-JOIN using the LEFT OUTER JOIN syntax. Include your 'extra' conditions from the second query in the JOIN condition, while the first conditions stay in the WHERE, like this:
select a.name, CASE WHEN b.Value IS NULL THEN 0 ELSE b.Value END AS Value
from
auxiliary_variable_inquiry a
LEFT JOIN
auxiliary_variable_inquiry b ON
a.name = b.name and -- replace this with your real ID-based JOIN
a.inquiry_idbr_code = b.inquiry_idbr_code AND
b.ru_ref = 20120000008 AND
b.period = 200912
where a.inquiry_idbr_code = '063'
if i got right, you should use something like:
SELECT i.NAME,
v.NAME,
v.value
FROM auxiliary_variable_inquiry i
LEFT JOIN auxiliary_variable_value v
ON i.inquiry_idbr_code = v.inquiry_idbr_code
WHERE v.ru_ref = 20120000008
AND v.period = 200912
select a.cust_xref_id, a.est_hour, a.phone_nbr as number, a.credit_calls, a.credit_rpcs, b.sdp_calls
from #temp0 a
full outer join #temp2 b
on a.cust_xref_id = b.sdp_cust_xref_id
and a.est_hour = b.sdp_hour
and a.phone_nbr = b.sdp_phone
Is there a way to get the data from table b with regard to sdp_cust_xref_id, sdp_hour, and sdp_phone when the data does not exist in both tables via the join? If b.sdp_calls does exist, the column values are null.
I read it a few more times and I think I know what you want. Try this. It will give you the values from table b if they are NULL in a:
select COALESCE(a.cust_xref_id, b.sdp_cust_xref_id) as cust_xref_id,
COALESCE(a.est_hour, b.spd_hour) as est_hour,
COALESCE(a.phone_nbr, b.spd_phone) as number,
a.credit_calls,
a.credit_rpcs,
b.sdp_calls
from #temp0 a
full outer join #temp2 b
on a.cust_xref_id = b.sdp_cust_xref_id
and a.est_hour = b.sdp_hour
and a.phone_nbr = b.sdp_phone