SQL Query Question - tsql

I am using the following query to list these records between specified dates.But ,it's not working.Also,don't gives me error.Just is coming blank screen.it's has column name.
Any problem the following query?
SET DATEFORMAT dmy
select *from tamirarizakaydi where tarih between '31.01.2011 ' and ' 04.02.2011'
thanks in advance.

The leading and trailing spaces don't make any difference as far as I can see.
SET DATEFORMAT dmy
select CAST('31.01.2011 ' as date) , CAST(' 04.02.2011' as date), CAST('31.01.2011 ' as datetime), CAST(' 04.02.2011' as datetime)
Returns
---------- ---------- ----------------------- -----------------------
2011-01-31 2011-02-04 2011-01-31 00:00:00.000 2011-02-04 00:00:00.000
I'm going to guess that tarih is stored as a string or you don't have any matching rows.
If tarih is a character based column then your query will be doing a lexicographic comparison and look for rows where tarih >= '31.01.2011 ' and 'tarih <= ' 04.02.2011' No rows can match this condition as the end of the range is alphabetically before the start of the range.

Related

Create date column from year and doy column

Is there a way to create a date column combining one column having the year as string and one column containing a date-of-year (doy) as integer?
I am aware of methods like SELECT EXTRACT(DOW FROM TIMESTAMP '2001-02-16 20:38:40'); or SELECT to_char(date_trunc('year', now()) + interval '169 days', 'MM/DD') but when trying to replace the "hard coded" stings with the columns I always get some kind of an error.
SELECT s.id, s.year, s.doy,
((s.year||'-01-01')::date + (s.doy||' days')::interval )::date AS date
FROM table_name AS s
the (s.year||'-01-01') or (s.doy||' days') concats the column value with a required string and the ::date or ::interval changes the resulting string type
You can use the make_date() function and add the number of days directly because date + integer is a valid operation:
select make_date(s.year, 1, 1) + s.doy as date
from ...

BigQuery - DATE_TRUNC error

trying to get the monthly aggregated data from Legacy table. Meaning date columns are strings:
amount date_create
100 2018-01-05
200 2018-02-03
300 2018-01-22
However, the command
Select DATE_TRUNC(DATE date_create, MONTH) as month,
sum(amount) as amount_m
from table
group by 1
Returns the following error:
Error: Syntax error: Expected ")" but got identifier "date_create"
Why does this query not run and what can be done to avoid the issue?
Thanks
It looks like you meant to cast date_create instead of using the DATE keyword (which is how you construct a literal value) there. Try this instead:
Select DATE_TRUNC(DATE(date_create), MONTH) as month,
sum(amount) as amount_m
from table
GROUP BY 1
I figured it out:
date_trunc(cast(date_create as date), MONTH) as Month
Another option for BigQuery Standard SQL - using PARSE_DATE function
#standardSQL
WITH `project.dataset.table` AS (
SELECT 100 amount, '2018-01-05' date_create UNION ALL
SELECT 200, '2018-02-03' UNION ALL
SELECT 300, '2018-01-22'
)
SELECT
DATE_TRUNC(PARSE_DATE('%Y-%m-%d', date_create), MONTH) AS month,
SUM(amount) AS amount_m
FROM `project.dataset.table`
GROUP BY 1
with result as
Row month amount_m
1 2018-01-01 400
2 2018-02-01 200
In practice - I prefer PARSE_DATE over CAST as former kind of documents expectation about data format
Try to add double quote to date_creat :
Select DATE_TRUNC('date_create', MONTH) as month,
sum(amount) as amount_m
from table
group by 1

I need to get 3 letter month as 'Jan', 'Feb' using extract () function from date column in postgresql

date column's format : '2017-03-17'
SELECT EXTRACT(MONTH FROM DATE '2017-03-17') FROM table;
It's giving me 3 instead of March.
extract() returns a number. You want a string, so you can use to_char(<col>, 'Mon'):
select to_char(now(), 'MON')
or for mixed case:
select to_char(now(), 'Mon')

PostgreSql - Adding YEar and Month to Table

I am creating a Customer table and i want one of the attributes to be Expiry Date of credit card.I want the format to be 'Month Year'. What data type should i use? i want to use date but the format is year/month/day. Is there any other way to restrict format to only Month and year?
You can constrain the date to the first day of the month:
create table customer (
cc_expire date check (cc_expire = date_trunc('month', cc_expire))
);
Now this fails:
insert into customer (cc_expire) values ('2014-12-02');
ERROR: new row for relation "customer" violates check constraint "customer_cc_expire_check"
DETAIL: Failing row contains (2014-12-02).
And this works:
insert into customer (cc_expire) values ('2014-12-01');
INSERT 0 1
But it does not matter what day is entered. You will only check the month:
select
date_trunc('month', cc_expire) > current_date as valid
from customer;
valid
-------
t
Extract year and month separately:
select extract(year from cc_expire) "year", extract(month from cc_expire) "month"
from customer
;
year | month
------+-------
2014 | 12
Or concatenated:
select to_char(cc_expire, 'YYYYMM') "month"
from customer
;
month
--------
201412
Use either
char(5) for two-digit years, or
char(7) for four-digit years.
Code below assumes two-digit years, which is the form that matches all my credit cards. First, let's create a table of valid expiration dates.
create table valid_expiration_dates (
exp_date char(5) primary key
);
Now let's populate it. This code is just for 2013. You can easily adjust the range by changing the starting date (currently '2013-01-01'), and the "number" of months (currently 11, which lets you get all of 2013 by adding from 0 to 11 months to the starting date).
with all_months as (
select '2013-01-01'::date + (n || ' months')::interval months
from generate_series(0, 11) n
)
insert into valid_expiration_dates
select to_char(months, 'MM') || '/' || to_char(months, 'YY') exp_date
from all_months;
Now, in your data table, create a char(5) column, and set a foreign key reference from it to valid_expiration_dates.exp_date.
While you're busy with this, think hard about whether "exp_month" might be a better name for that column than "exp_date". (I think it would.)
As another idea you could essentially create some brief utilities to do this for you using int[]:
CREATE OR REPLACE FUNCTION exp_valid(int[]) returns bool LANGUAGE SQL IMMUTABLE as
$$
SELECT $1[1] <= 12 AND (select count(*) = 2 FROM unnest($1));
$$;
CREATE OR REPLACE FUNCTION first_invalid_day(int[]) RETURNS date LANGUAGE SQL IMMUTABLE AS
$$
SELECT (to_date($1[2]::text || $1[1]::text, CASE WHEN $1[2] < 100 THEN 'YYMM' ELSE 'YYYYMM' END) + '1 month'::interval)::date;
$$;
These work:
postgres=# select exp_valid('{04,13}');
exp_valid
-----------
t
(1 row)
postgres=# select exp_valid('{13,04}');
exp_valid
-----------
f
(1 row)
postgres=# select exp_valid('{04,13,12}');
exp_valid
-----------
f
(1 row)
Then we can convert these into a date:
postgres=# select first_invalid_day('{04,13}');
first_invalid_day
-------------------
2013-05-01
(1 row)
This use of arrays does not violate any normalization rules because the array as a whole represents a single value in its domain. We are storing two integers representing a single date. '{12,2}' is December of 2002, while '{2,12}' is Feb of 2012. Each represents a single value of the domain and is therefore perfectly atomic.

to_char() issue in PostgreSQL

I have a PostgreSQL table with a field named effective_date and data type is integer(epoch date). What I want to do is to select only the entries that have an effective_date of my choice (I only want to query by the month). My query is below and the problem is, it is not returning anything although the table do have many entries that match the selection criteria.
$query = "select *
from ". $this->getTable() ."
where pay_stub_entry_name_id = 43
AND to_char(effective_date, 'Mon') = 'Jul'
AND deleted = 0";
Use extract(month from the_date) instead of to_char. See datetime functions in the Pg docs.
With to_char you'll suffer from all sorts of issues with case, localisation, and more.
Assuming you meant that the data type of effective_date was timestamp or date, you'd write:
$query = "select *
from ". $this->getTable() ."
where pay_stub_entry_name_id = 43
AND extract(month from effective_date) = 7
AND deleted = 0";
If it's integer then - assuming it's an epoch date - you have to convert it to a timestamp with to_timestamp, then use extract on it. See the epoch section in the documentation linked to above, eg:
$query = "select *
from ". $this->getTable() ."
where pay_stub_entry_name_id = 43
AND extract(month from to_timestamp(effective_date)) = 7
AND deleted = 0";
The immediate cause of your problem was that you were calling to_char(integer,text) with an integer epoch date. Only the timestamp versions of to_char do date formatting; Mon isn't special for the others, so it was simply output as a literal string Mon. Compare:
regress=# SELECT to_char(current_timestamp, 'Mon');
to_char
---------
Aug
(1 row)
regress=# select to_char( extract(epoch from current_timestamp), 'Mon');
to_char
---------
Mon
(1 row)
Remember to parameterise your real-world versions of these queries to help avoid SQL injection.