Recursive Query for Date Range - sql

I'm trying to create a query so that I can generate a date range between a specific start and end point.
I have the following:
WITH DATE_RANGE(DATE_FOR_SHIFT)
AS (SELECT DATE('2015-04-01')
FROM SYSIBM.SYSDUMMY1
UNION ALL
SELECT DATE_FOR_SHIFT + 1 DAY
FROM DATE_RANGE
WHERE DATE_FOR_SHIFT <= #END)
SELECT DATE_FOR_SHIFT
FROM DATE_RANGE;
Output (assuming that #END equals 2015-05-01):
2015-04-01
2015-04-02
2015-04-03
2015-04-04
...
2015-05-01
The output is correct, but I want to be able to change the start and points based on parameters provided rather than having to rewrite the query or have a SQL injection prone query.
How would I rewrite this query in order to accomplish this?

Your SELECT is fine, other than the hard coded start date.
What I think you're missing is wrapping it in either a stored procedure or user defined table function (UDTF). Assuming you'll want to JOIN the date range to other tables, I'd suggest a UDTF.
create function date_range (#str date, #end date)
returns table (date_for_shift date)
language SQL
reads SQL data
return
WITH DATE_RANGE(DATE_FOR_SHIFT)
AS (SELECT #str
FROM SYSIBM.SYSDUMMY1
UNION ALL
SELECT DATE_FOR_SHIFT + 1 DAY
FROM DATE_RANGE
WHERE DATE_FOR_SHIFT <= #END)
SELECT DATE_FOR_SHIFT
FROM DATE_RANGE;
Then you'd call it...
select * from table(date_range(date('2015-04-01'),date('2015-05-01'))) as tbl;
However, instead of generating this date range on the fly....consider simply creating a calender (aka dates) table. Basically just a table with dates from say 1900-01-01 to 2500-12-31..or whatever you'd like. Beside the date column, you can include lots of additional columns such as business_day, holiday, ect.. that make life much easier.
Google "SQL calendar table" for plenty of examples.

A bit of playing with this in perl gives me:
#!/opt/myperl/5.20.2/bin/perl
use 5.10.0;
use DBI;
use DBD::DB2;
use Data::Dump;
my $sql = <<EOSQL;
WITH DATE_RANGE(DATE_FOR_SHIFT)
AS (SELECT CAST(? AS DATE)
FROM SYSIBM.SYSDUMMY1
UNION ALL
SELECT DATE_FOR_SHIFT + 1 DAY
FROM DATE_RANGE
WHERE DATE_FOR_SHIFT < CAST(? AS DATE))
SELECT DATE_FOR_SHIFT
FROM DATE_RANGE;
EOSQL
my $dbh = DBI->connect('dbi:DB2:sample');
my $sth = $dbh->prepare_cached($sql);
$sth->execute('2015-04-01','2015-05-01');
my $rc = $sth->fetchall_arrayref();
dd($rc);
This does give an error during prepare ("The recursive common table expression "MYSCHEMA.DATE_RANGE" may contain an infinite loop") that I haven't figured out yet, but the fetch does work, the final return goes from 04-01 to 05-01. Hopefully you can port this to your desired language.

Related

Find data with specific date and month only

I am trying to find a data with specific where clause of date and month but I am receiving an error can anyone help me with this?
select *
from my_data
where date BETWEEN '11-20' AND '12-15'
MS SQL Server Management Studio
I am receving an error
Conversion failed when converting date and/or time from character string
Most databases support functions to extract components of dates. So, one way of doing what you want is to convert the values to numbers and make a comparison like this:
where month(date) * 100 + day(date) between 1120 and 1215
The functions for extracting date parts differ by database, so your database might have somewhat different methods for doing this.
The conversion is failing because you are not specifying a year. If you were to specify '11-20-2015' your query would work just insert whatever year you need.
SELECT *
FROM my_data
WHERE date BETWEEN '11-20-2015' AND '12-15-2015'
Alternatively if you wanted data from that range of dates for multiple years I would use a while loop to insert information in a # table then read from that table, depending on the amount of data this could be quick or sloooowww here is an example.
DECLARE #mindatestart date, #mindateend date, #maxdatestart date
SET #mindatestart = '11-20-2010'
SET #mindateend = '12-15-2010'
SET #maxdatestart = '11-20-2015'
SELECT top 0 *, year = ' '
INTO #mydata
FROM my_data
WHILE #mindatestart < #maxdatestart
BEGIN
INSERT INTO #mydata
SELECT *, YEAR(#mindatestart)
FROM my_data
where date between #mindatestart and #mindateend
SET #mindatestart = DATEADD(Year, 1, #mindatestart)
SET #mindateend = DATEADD(Year, 1, #mindateend)
END
This will loop and insert the data from 2010-2015 for those date ranges and add a extra column on the end so you can call the data and order by year if you want like this
SELECT * FROM #mydata order by YEAR
Hopefully some part of this helps!
FROM THE COMMENT BELOW
SELECT *
FROM my_data
WHERE DAY(RIGHT(date, 5)) between DAY(11-20) and DAY(12-15)
The reason '11-20' doesn't work is because its a character string which is why you have to input it between ' ' What the Month() function does is take whatever you put between the () and convert it to an integer. Which is why you're not getting anything back using the method in the first answer, the '-Year' from the table date field is being added into the numeric value where your value is just being converted from 11-20 you can see by using these queries
SELECT MONTH(11-20) --Returns 12
SELECT MONTH(11-20-2015) -- Returns 6
SELECT MONTH(11-20-2014) -- Returns 6
Using RIGHT(Date, 5) you only get Month-day, then you date the day value of that so DAY(RIGHT(DATE, 5) and you should get something that in theory should fall within those date ranges despite the year. However I'm not sure how accurate the data will be, and its a lot of work just to not add an additional 8 characters in your original query.
Since you only care about month and day, but not year, you need to use DATEPART to split up the date. Try this:
select *
from my_data
WHERE 1=1
AND (DATEPART(m, date) >= 11 AND DATEPART(d,date) >= 20)
AND (DATEPART(m, date) <= 12 AND DATEPART(d,date) <= 15)

SQL. Select Unixtime for whole day

I am looking for a way to select a whole days worth of data from a where statement. Timestamp is in unix time such as (1406045122). I want to select the today's date of unix time range and find all the food that has been added in today. Thank in advance. This is the code I wrote. I'm not sure what I should put in the ( ????? ) part. I know it has to do with 60*60*24=86400 secs per day but I'm not too sure how I can implement this.
Select timestamp,food from table1 where timestamp = ( ????? );
Select timestamp,food
FROM table1
WHERE timestamp > :ts
AND timestamp <= (:ts + 86400);
replace :ts with the starting timstamp and you'll filter a whole day's worth of data
edit
This select query would give you the current timestamp (there may be more efficient ones, i don't work with sqlite often)
select strftime("%s", current_timestamp);
You can find more info about them here: http://www.tutorialspoint.com/sqlite/sqlite_date_time.htm
Using the strftime() function, combined with the date() function we can write this following query which will not need any manual editing. It will return the records filtered on timestamp > start of today & timestamp <= end of today.
Select timestamp,food
FROM table1
WHERE timestamp > strftime("%s", date(current_timestamp))
AND timestamp <= (strftime("%s", date(current_timestamp)) + 86400);
Your mileage will likely depend on your version of SQL but for example on MySQL you can specify a search as being BETWEEN two dates, which is taken conventionally to mean midnight on each. So
SELECT * FROM FOO WHERE T BETWEEN '2014-07-01' AND '2014-07-02';
selects anything with a timestamp anywhere on 1st July 2014. If you want to make it readable you could even use the ADDDATE function. So you could do something like
SET #mydate = DATE(T);
SELECT * FROM FOO WHERE T BETWEEN #mydate AND ADDDATE(#mydate, 1);
The first line should truncate your timestamp to be 00:00:00. The second line should SELECT only records from that date.

How to select rows by date in sqlite

I have to select all rows from database by just passing date. For example to get all rows that have date 10/23/2012
In sqlite db I store this in DATE column:
01/01/1900 11:00:00 AM
I have tried to get by using date() but I get nothing for date:
select itemId, date(dateColumn) from items
So all I need is to compare only dates but can't find how to do this in sqlite.
Firstly, format your dates to the ISO-8601 standard. Wrap it in Date() to ensure it gets processed as a DATE. Finally, construct your range so that it will include everything from 12:00am onwards until just before 12:00am the next day.
select itemId, dateColumn
from items
where dateColumn >= date('2012-10-23')
AND dateColumn < date('2012-10-23', '+1 day')
SQLite columns are not typed. However, if you compare the column to a DATE as shown, it is sufficient to coerced the column data into dates (null if not coercible) and the comparison will work properly.
Example on SQLFiddle:
create table items (
itemid, datecolumn);
insert into items select
1,'abc' union all select
2,null union all select
3,'10/23/2012 12:23' union all select
4,'10/23/2012' union all select
5,'2012-10-23 12:23' union all select
6,'2012-10-23' union all select
7,'2012-10-24 12:23' union all select
8,'2012-10-24' union all select
9,date('2012-10-24 12:23') union all select
10,date('2012-10-24');
Results:
itemid datecolumn
5 2012-10-23 12:23
6 2012-10-23
Note that although rows 3 and 4 appear to be dates, they are not, because they do not conform to ISO-8601 formatting which is the only format recognized by SQLite.
In SQLite, there is no datatype DATE, it's stored as strings. Therefor, the Strings have to match exactly to be equal.
Since we don't want that, you'll want to "cast" the values from the date-column to pseudo-date and also cast your argument to a pseudo-date, so they can be compared:
SELECT itemId FROM items WHERE date(dateColumn) = date("2012-10-22");
Note that the date-command takes dates formated as YYYY-MM-DD, as further explained in an answer to this older question. The question also shows that you can use the BETWEEN x AND y-command to get dates, matching a range.
SELECT itemId,dateColumn FROM items WHERE dateColumn=date('YYYY-MM-DD HH:MM:SS');
SQLite Reference
select itemId,dateColumn from items
where dateColumn = #date

SQL to Return Dates for Selected Week Only

I'm writing a SQL query on a timesheet report. I need the report to return only the details for the week of the selected date.
E.g., if I pick 02/01/2012 (dd/MM/yyyy), then it should only return results between 02/01/2012 and 08/01/2012.
Thanks
SELECT
*
FROM
yourTable
WHERE
dateField >= #yourDate
AND dateField < #yourDate + 7
Some variations of SQL may have specific ways of adding 7 days to a datevalue. Such as...
- DateAdd(Day, 7, #date)
- DATE_ADD(#date, INTERVAL 7 DAYS)
- etc, etc
This option is both index friendly, and is resilient to database fields that have time parts as well as date parts.
You easiest is the equivalent of WEEK_OF_YEAR function in your SQL engine
But you can also use DATE_ADD
WHERE table.date BETWEEN target_date AND DATE_ADD(target_date,INTERVAL 7 DAY)
That depends on the database system you're using. MySQL has a function calles WEEK(), SQL Server can do something like this with the DATEPART() function:
MySQL:
SELECT
*
FROM table
WHERE WEEK(date_col) = WEEK('02/01/2012');
SQL SERVER:
SELECT
*
FROM table
WHERE DATEPART(WEEK, datecol) = DATEPART(WEEK,'02/01/2012');
SELECT * FROM table_name
WHERE date BETWEEN '1/02/2012' AND '1/08/2012';
you can replace the example date with your date and yourdate + 6.
Look here for example: http://www.roseindia.net/sql/sql-between-datetime.shtml

How to get one day ahead of a given date?

Suppose I have a date 2010-07-29. Now I would like to check the result of one day ahead. how to do that
For example,
SELECT *
from table
where date = date("2010-07-29")
How to do one day before without changing the string "2010-07-29"?
I searched and get some suggestion from web and I tried
SELECT *
from table
where date = (date("2010-07-29") - 1 Day)
but failed.
MySQL
SELECT *
FROM TABLE t
WHERE t.date BETWEEN DATE_SUB('2010-07-29', INTERVAL 1 DAY)
AND '2010-07-29'
Change DATE_SUB to DATE_ADD if you want to add a day (and reverse the BETWEEN parameters).
SQL Server
SELECT *
FROM TABLE t
WHERE t.date BETWEEN DATEADD(dd, -1, '2010-07-29')
AND '2010-07-29'
Oracle
SELECT *
FROM TABLE t
WHERE t.date BETWEEN TO_DATE('2010-07-29', 'YYYY-MM-DD') - 1
AND TO_DATE('2010-07-29', 'YYYY-MM-DD')
I used BETWEEN because the date column is likely DATETIME (on MySQL & SQL Server, vs DATE on Oracle), which includes the time portion so equals means the value has to equal exactly. These queries give you the span of a day.
If you're using Oracle, you can use the + and - operators to add a number of days to a date.
http://psoug.org/reference/date_func.html
Example:
SELECT SYSDATE + 1 FROM dual;
Will yield tomorrow's date.
If you're not using Oracle, please tell use what you ARE using so we can give better answers. This sort of thing depends on the database you are using. It will NOT be the same across different databases.
Depends of the DateTime Functions available on the RDBMS
For Mysql you can try:
mysql> SELECT DATE_ADD('1997-12-31',
-> INTERVAL 1 DAY);
mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY);
-> '1997-12-02'
If youre using MSSQL, you're looking for DateAdd() I'm a little fuzzy on the syntax, but its something like:
Select * //not really, call out your columns
From [table]
Where date = DateAdd(dd, -1, "2010-07-29",)
Edit: This syntax should be correct: it has been updated in response to a comment.
I may have the specific parameters in the wrong order, but that should get you there.
In PL SQL : select sysdate+1 from dual;