Suppose my table user_info has 2 columns, one is #username and another one is #info.
Now I already made a query "INSERT INTO user_info(username) value('')
How can I make another query to put data on column #info for the same username?? Because after the first query I'll have null for the column #info I believe.
Just to clarify, I don't get the #info when I have the username. Each user will get their info later. So I can't put then on the same query.
In that case, you need to update the row, simply using update on where the username exist
From documentation:
UPDATE table_name
SET column1 = value1,
column2 = value2,
...
WHERE condition;
Your case:
UPDATE user_info
SET info='new_information'
WHERE username='existing_username'
Related
Our system uses postgres for its database.
We have queries that can select rows from a database table where an array field in the table contains a specific value, e.g.:
Find which employee manages the employee with ID 123.
staff_managed_ids is a postgres array field containing an array of the employees that THIS employee manages.
This query works as expected:
select *
from employees
where 123=any(staff_managed_ids)
We now need to query where an array field contains a postgres NULL. We tried the following query, but it doesn't work:
select *
from employees
where NULL=any(staff_managed_ids)
We know the staff_managed_ids array field contains NULLs from other queries.
Are we using NULL wrongly?
NULL can not be compared using =. The only operators that work with that are IS NULL and IS NOT NULL.
To check for nulls, you need to unnest the elements:
select e.*
from employees e
where exists (select *
from unnest(e.staff_managed_ids) as x(staff_id)
where x.staff_id is null);
if all your id values are positive, you could write something like this:
select *
from employees
where (-1 < all(staff_managed_ids)) is null;
how this works is that -1 should be less than all values, however comparison with null will make the whole array comparison expression null.
I have a data table with 3 columns. Datable table Named Usertable with columns labeled UserID, UserFavFood, UsersFavSport. Each column has many rows (+100). I would like to search the UserID where UserID = 1234, update rows that need to be updated, and delete the remainder/non updated rows where UserID = 1234. Is it faster to just delete all UserID=1234 and then repopulate it with new info or is there a way to update where UserID = 1234 and delete remaining rows that UserID = 1234?
I'm using PostgresSQL and I've tried deleting and reinserting but I am doing something wrong.
DELETE FROM Usertable WHERE UserID = '1234'
AND
INSERT into Usertable(UserID, UserFavFood, UsersFavSport)
VALUES('1234', 'Chicken', 'Baseball')
Is it possible to send the values in Lists of three? As in
Values = ['1234', 'Chicken', 'baseball'],['1234', 'Cheese', 'Soccer']?
In Postgres 8.2 or later the VALUES clause can take multiple tuples:
INSERT INTO Usertable (UserID, UserFavFood, UsersFavSport)
VALUES
('1234', 'Chicken', 'Baseball'),
('1234', 'Cheese', 'Soccer');
Regarding executing the delete and insert together, you would have to use a transaction as far as I know.
For each row in table exam 'where exam.examRegulation isnull', I want to insert one corresponding row in table examRegulation and copy columnvalues from exam to examregulation. Apparently the following query ist too naive and must be approved:
insert into examRegulation (graduation, course, examnumber, examversion)
values (exam.graduation, exam.course, exam.examnumber, exam.examversion)
where ?? (select graduation, course, examnumber, examversion
from exam
where exam.examRegulation isnull)
Is there a way to do this in postgresql?
You may rephrase this as an INSERT INTO ... SELECT statement:
INSERT INTO examRegulation (graduation, course, examnumber, examversion)
SELECT graduation, course, examnumber, examversion
FROM exam
WHERE examRegulation IS NULL;
The VALUES clause, as the name implies, can only be used with literal values. If you need to populate an insert using query logic, then you need to use a SELECT clause.
I have the following code in Postgres
select op.url from identity.legal_entity le
join identity.profile op on le.legal_entity_id =op.legal_entity_id
where op.global_id = '8wyvr9wkd7kpg1n0q4klhkc4g'
which returns 1 row.
Then I try to update the url field with the following:
update identity.profile
set url = 'htpp:sam'
where identity.profile.url in (
select op.url from identity.legal_entity le
join identity.profile op on le.legal_entity_id =op.legal_entity_id
where global_id = '8wyvr9wkd7kpg1n0q4klhkc4g'
);
But the above ends up updating more than 1 row, actually all of the rows of the identity table.
I would assume since the first postgres statement returns one row, only one row at most can be updated, but I am getting the wrong effect where all of the rows are being updated. Why ?? Please help a nubie fix the above update statement.
Instead of using profile.url to identify the row you want to update, use the primary key. That is what it is there for.
So if the primary key column is called id, the statement could be modified to:
UPDATE identity.profile
SET ...
WHERE identity.profile.id IN (SELECT op.id FROM ...);
But you can do this much simpler in PostgreSQL with
UPDATE identity.profile op
SET url = 'htpp:sam'
FROM identity.legal_entity le
WHERE le.legal_entity_id = op.legal_entity_id
AND le.global_id = '8wyvr9wkd7kpg1n0q4klhkc4g';
Context: I want to increase the allowance value of some employees from £1875 to £7500, and update their balance to be £7500 minus whatever they have currently used.
My Update statement works for one employee at a time, but I need to update around 200 records, out of a table containing about 6000.
I am struggling to workout how to modify the below to update more than one record, but only the 200 records I need to update.
UPDATE employeeaccounts
SET xml = To_clob(Updatexml(Xmltype(xml),
'/EmployeeAccount/CurrentAllowance/text()',187500,
'/EmployeeAccount/AllowanceBalance/text()',
750000 - (SELECT Extractvalue(Xmltype(xml),
'/EmployeeAccount/AllowanceBalance',
'xmlns:ts=\"http://schemas.com/\", xmlns:xt=\"http://schemas.com\"'
)
FROM employeeaccounts
WHERE id = '123456')))
WHERE id = '123456'
Example of xml column (stored as clob) that I want to update. Table has column ID that hold PK of employees ID EG 123456
<EmployeeAccount>
<LastUpdated>2016-06-03T09:26:38+01:00</LastUpdated>
<MajorVersion>1</MajorVersion>
<MinorVersion>2</MinorVersion>
<EmployeeID>123456</EmployeeID>
<CurrencyID>GBP</CurrencyID>
<CurrentAllowance>187500</CurrentAllowance>
<AllowanceBalance>100000</AllowanceBalance>
<EarnedDiscount>0.0</EarnedDiscount>
<NormalDiscount>0.0</NormalDiscount>
<AccountCreditLimit>0</AccountCreditLimit>
<AccountBalance>0</AccountBalance>
</EmployeeAccount>
You don't need a subquery to get the old balance, you can use the value from the current row; which means you don't need to correlate that subquery and can just use an in() in the main statement:
UPDATE employeeaccounts
SET xml = To_clob(Updatexml(Xmltype(xml),
'/EmployeeAccount/CurrentAllowance/text()',187500,
'/EmployeeAccount/AllowanceBalance/text()',
750000 - Extractvalue(Xmltype(xml),
'/EmployeeAccount/AllowanceBalance',
'xmlns:ts=\"http://schemas.com/\", xmlns:xt=\"http://schemas.com\"')
))
WHERE id in (123456, 654321, ...);