So I have been doing pretty well on my project (Link to previous StackOverflow question), and have managed to learn quite a bit, but there is this one problem that has been really dogging me for days and I just can't seem to solve it.
It has to do with using the UNIX_TIMESTAMP call to convert dates in my SQL database to UNIX time-format, but for some reason only one set of dates in my table is giving me issues!
==============
So these are the values I am getting -
#abridged here, see the results from the SELECT statement below to see the rest
#of the fields outputted
| firstVst | nextVst | DOB |
| 1206936000 | 1396238400 | 0 |
| 1313726400 | 1313726400 | 278395200 |
| 1318910400 | 1413604800 | 0 |
| 1319083200 | 1413777600 | 0 |
when I use this SELECT statment -
SELECT SQL_CALC_FOUND_ROWS *,UNIX_TIMESTAMP(firstVst) AS firstVst,
UNIX_TIMESTAMP(nextVst) AS nextVst, UNIX_TIMESTAMP(DOB) AS DOB FROM people
ORDER BY "ref DESC";
So my big question is: why in the heck are 3 out of 4 of my DOBs being set to date of 0 (IE 12/31/1969 on my PC)? Why is this not happening in my other fields?
I can see the data quite well using a more simple SELECT statement and the DOB field looks fine...?
#formatting broken to change some variable names etc.
select * FROM people;
| ref | lastName | firstName | DOB | rN | lN | firstVst | disp | repName | nextVst |
| 10001 | BlankA | NameA | 1968-04-15 | 1000000 | 4600000 | 2008-03-31 | Positive | Patrick Smith | 2014-03-31 |
| 10002 | BlankB | NameB | 1978-10-28 | 1000001 | 4600001 | 2011-08-19 | Positive | Patrick Smith | 2011-08-19 |
| 10003 | BlankC | NameC | 1941-06-08 | 1000002 | 4600002 | 2011-10-18 | Positive | Patrick Smith | 2014-10-18 |
| 10004 | BlankD | NameD | 1952-08-01 | 1000003 | 4600003 | 2011-10-20 | Positive | Patrick Smith | 2014-10-20 |
It's because those DoB's are from before 12/31/1969, and the UNIX epoch starts then, so anything prior to that would be negative.
From Wikipedia:
Unix time, or POSIX time, is a system for describing instants in time, defined as the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, not counting leap seconds.
A bit more elaboration: Basically what you're trying to do isn't possible. Depending on what it's for, there may be a different way you can do this, but using UNIX timestamps probably isn't the best idea for dates like that.
Related
Using MS access SQL I have a query (actually a UNION made of multiple queries) and need a cumulative sum (actually a statement of account which items are in chronological order).
How do I get a cumulative sum?
Since they are duplicates by date I have to add a new ID, however, SQL in MS access does not seem to have ROW_ID or similar.
So, we need to sort donation data into chronological order across multiple tables with duplicates. First combine all the tables of donators in one query which sets up the simplest syntax. Then to put things in order we need to have an order for the duplicate dates. The dataset has two natural ways to sort duplicate dates including the donator and the amount. For instance, we could decide that after the date bigger donations come first, If the rule is complicated enough we abstract it to a code module and into public function and include it in the query so that we can sort by it:
'Sorted Donations:'
SELECT (BestDonator(q.donator)) as BestDonator, *
FROM tblCountries as q
UNION SELECT (BestDonator(j.donator)) as BestDonator, *
FROM tblIndividuals as j
ORDER BY EvDate Asc, Amount DESC , BestDonator DESC;
Public Function BestDonator(donator As String) As Long
BestDonator = Len(donator) 'longer names are better :)'
End Function
with sorted donations we have settled on an order for the duplicate dates and have combined both individual donations and country donations, so now we can calculate the running sum directly using either dsum or a subquery. There is no need to calculate row id. The tricky part is getting the syntax correct. I ended up abstracting the running sum calculation to a function and omitting BestDonator because I couldn't easily paste together this query in the query designer and I ran out of time to bug fix
Public Function RunningSum(EvDate As Date, Amount As Currency)
RunningSum = DSum("Amount", "Sorted Donations", "(EvDate < #" & [EvDate] & "#) OR (EvDate = #" & [EvDate] & "# AND Amount >= " & [Amount] & ")")
End Function
Carefully note the OR in the Dsum part of the RunningSum calculation. This is the tricky part to summing the right amounts.
'output
-------------------------------------------------------------------------------------
| donator | EvDate | Amount | RunningSum |
-------------------------------------------------------------------------------------
| Reiny | 1/10/2020 | 321 | 321 |
-------------------------------------------------------------------------------------
| Czechia | 3/1/2020 | 7455 | 7776 |
-------------------------------------------------------------------------------------
| Germany | 3/18/2020 | 4222 | 11998 |
-------------------------------------------------------------------------------------
| Jim | 3/18/2020 | 222 | 12220 |
-------------------------------------------------------------------------------------
| Australien | 4/15/2020 | 13423 | 25643 |
-------------------------------------------------------------------------------------
| Mike | 5/31/2020 | 345 | 25988 |
-------------------------------------------------------------------------------------
| Portugal | 6/6/2020 | 8755 | 34743 |
-------------------------------------------------------------------------------------
| Slovakia | 8/31/2020 | 3455 | 38198 |
-------------------------------------------------------------------------------------
| Steve | 9/6/2020 | 875 | 39073 |
-------------------------------------------------------------------------------------
| Japan | 10/10/2020 | 5234 | 44307 |
-------------------------------------------------------------------------------------
| John | 10/11/2020 | 465 | 44772 |
-------------------------------------------------------------------------------------
| Slowenia | 11/11/2020 | 4665 | 49437 |
-------------------------------------------------------------------------------------
| Spain | 11/22/2020 | 7677 | 57114 |
-------------------------------------------------------------------------------------
| Austria | 11/22/2020 | 3221 | 60335 |
-------------------------------------------------------------------------------------
| Bill | 11/22/2020 | 767 | 61102 |
-------------------------------------------------------------------------------------
| Bert | 12/1/2020 | 755 | 61857 |
-------------------------------------------------------------------------------------
| Hungaria | 12/24/2020 | 9996 | 71853 |
-------------------------------------------------------------------------------------
I have a table with the following structure and data in it:
| ID | Date | Result |
|---- |------------ |-------- |
| 1 | 30/04/2020 | + |
| 1 | 01/05/2020 | - |
| 1 | 05/05/2020 | - |
| 2 | 03/05/2020 | - |
| 2 | 04/05/2020 | + |
| 2 | 05/05/2020 | - |
| 2 | 06/05/2020 | - |
| 3 | 01/05/2020 | - |
| 3 | 02/05/2020 | - |
| 3 | 03/05/2020 | - |
| 3 | 04/05/2020 | - |
I'm trying to write an SQL query (I'm using SQL Server) which returns the date of the first two consecutive negative results for a given ID.
For example, for ID no. 1, the first two consecutive negative results are on 01/05 and 05/05.
The first two consecutive results for ID No. 2 are on 05/05 and 06/05.
The first two consecutive negative results for ID No. 3 are on on 01/05 and 02/05 .
So the query should produce the following result:
| ID | FirstNegativeDate |
|---- |------------------- |
| 1 | 01/05 |
| 2 | 05/05 |
| 3 | 01/05 |
Please note that the dates aren't necessarily one day apart. Sometimes, two consecutive negative tests may be several days apart. But they should still be considered as "consecutive negative tests". In other words, two negative tests are not 'consecutive' only if there is a positive test result in between them.
How can this be done in SQL? I've done some reading and it looks like maybe the PARTITION BY statement is required but I'm not sure how it works.
This is a gaps-and-island problem, where you want the start of the first island of '-'s that contains at least two rows.
I would recommend lead() and aggregation:
select id, min(date) first_negative_date
from (
select t.*, lead(result) over(partition by id order by date) lead_result
from mytable t
) t
where result = '-' and lead_result = '-'
group by id
Use LEAD or LAG functions over ID partition ordered by your Date column.
Then simple check where LEAD/LAG column is equal to Result.
You'll need also to filter the top ones.
The image attached just shows what LEAD/LAG would return
I am trying to write up a Microsoft Access query that will return all of the data in a table where the assigned "Due By" date is within a day.
Meaning, when I come into the office in the AM, I should be able to run this query to see what was due yesterday and what is due today. Here is an example of the data:
| ID | JobName | DueBy |
|----|-------------------------|-----------|
| 1 | Sergio Pizza | 5/5/2018 |
| 2 | Hopkins Hospital | 9/1/2018 |
| 3 | Perry Hall High School | 9/25/2018 |
| 4 | Parkville High School | 9/24/2018 |
| 5 | Jim's House | 9/24/2018 |
My current query is:
SELECT tblBid.*
FROM tblBid
WHERE (((tblBid.Due_By)>=(Now()-2)));
Which works in returning the correct dataset:
| ID | JobName | DueBy |
|----|-------------------------|-----------|
| 3 | Perry Hall High School | 9/25/2018 |
| 4 | Parkville High School | 9/24/2018 |
| 5 | Jim's House | 9/24/2018 |
However, why do I need to write NOW()-2 and not NOW()-1? Why do I have to go back two days? When I write NOW()-1 I only get ID 3 for Perry Hall High School
Thank you!
Use DateDiff:
SELECT tblBid.*
FROM tblBid
WHERE DateDiff("d", tblBid.Due_By, Date()) Between 1 and 0;
You are using the Now() function which returns the current date & time, the dates in your table don't have a time part making them 12AM of that date, thus before Now() - 1, you need to use the Date() function which returns the date at 12AM and then you can use it as Date() - 1
This is a bit of a complicated question to ask, but I am sure someone here will know the answer in about 2 minutes and I'll feel stupid.
What I have is a table of routes, delivery names, and delivery times. Let's say it looks like this:
+------------+---------------+-------+
| ROUTE CODE | NAME | TIME |
+------------+---------------+-------+
| A | McDonald's | 5:30 |
| A | Arby's | 5:45 |
| A | Burger King | 6:00 |
| A | Wendy's | 6:30 |
| B | Arby's | 7:45 |
| B | Arby's | 7:45 |
| B | Burger King | 8:30 |
| B | McDonald's | 9:00 |
| C | Wendy's | 9:30 |
| C | Lion's Choice | 8:15 |
| C | Steak N Shake | 9:50 |
| C | Hardee's | 10:30 |
+------------+---------------+-------+
What I want the result to return is something like this:
+------------+---------------+------+
| ROUTE CODE | NAME | TIME |
+------------+---------------+------+
| A | McDonald's | 5:30 |
| B | Arby's | 7:45 |
| C | Lion's Choice | 8:15 |
+------------+---------------+------+
So what I want is the name of the minimum time for each route code.
I have written a query that gets me most of the way there (and feel free to improve upon this query if you think there is a more efficient way to do it):
SELECT main1.route_code, main1.first_stop, main2.name
FROM
(SELECT route_code, min(time) as first_stop FROM table1 WHERE date = yesterday GROUP BY route_code) main1
JOIN
(SELECT route_code, name, time FROM table1 WHERE date = yesterday) main2
ON main1.route_code = main2.route_code and main1.first_stop = main2.time
Here is where I need your help though. If I have identical times, it returns that row twice, and I only want it once. So for instance, the above query would return Arby's for route code "B" twice because it has the same time. I only want to see that once, I never want to see anything from a route more than once.
Can anyone help me? Thanks much!
In Postgres, you can use distinct on:
select distinct on (route_code) t.*
from table1 t
order by route_code, time asc;
This is likely to be the fastest method in Postgres. For performance, an index on (route_code, time) is recommended.
Here's another way to get your result that you may or may not like better:
SELECT route_name, time, name FROM
(SELECT *, ROW_NUMBER() OVER (PARTITION BY route_code ORDER BY time ASC) row_num FROM table1) subq
WHERE row_num = 1;
Sorry, I'm very new to SQL. I just learned it few hours ago. I'm using MariaDB + InnoDB Engine with HeidiSQL software + CodeIgniter 3. Let's say I have a table named disciples with the following data:
-------------------
| sort_id | name |
-------------------
| 1 | Peter |
| 4 | John |
| 3 | David |
| 5 | Petrus |
| 2 | Matthew |
-------------------
I'm fully aware that it's better to have a column called sort_id to be able to fetch the data using ORDER BY if I prefer a custom sorting. But if I delete row 3, the new table will look like this:
-------------------
| sort_id | name |
-------------------
| 1 | Peter |
| 4 | John |
| 5 | Petrus |
| 2 | Matthew |
-------------------
The thing is I'm having OCD (imagine there are 1000 rows), it hurts my eyes to see this mess with some missing numbers (in this case number 3 - see the above table) under sort_id. I think it has something to do with "relational database". Is there a way to quickly and automatically "re-assign/reset" new sort_id numbers to given rows and sort them ASC order according to the name using SQL code without having to do it manually?
-------------------
| sort_id | name |
-------------------
| 1 | John |
| 2 | Matthew |
| 3 | Peter |
| 4 | Petrus |
-------------------
I figured this out after reading the answer from Lynn Crumbling.
She made me realized I need a primary key in order to have a better management for my rows which is exactly what I was looking for. It happens that InnoDB automatically creates a primary key and is hidden from HeidiSQL interface unless I specify a specific column for example id. Now, I can re-organize my table rows by editing the primary key id and the table row will automatically sort itself the way I want. Before this, I edited the sort_id but the data did not update accordingly because it was not the primary key.
------------------------
| id | sort_id | name |
------------------------
| 1 | 1 | Peter |
| 2 | 4 | John |
| 3 | 5 | Petrus |
| 4 | 2 | Matthew |
------------------------
Thank you.