SQL Server: Inconsistencies in date - sql

create table #temp
(
A date
)
insert into #temp(A)
values(GETDATE())
insert into #temp(A)
values(GETDATE()-1)
Now when I query the table as
select A from #temp where A>=GETDATE() and A<=GETDATE()
I get no records
But GETDATE() record value should satisfy my where condition, shouldn't it at least pass me one record?
Please guide me if I am missing some point here.

You need to do conversion, so it seems :
where a >= convert(date, dateadd(day, -1, getdate())) and
a <= convert(date, getdate());
Your where clause comparing date as :
where a >= '2020-04-21 16:01:27.277' and a <= '2020-04-21 16:01:27.277'
So, you need to convert date because getdate()will also return time portions.
Since your where clause looks for single day so you can do :
where a = convert(date, getdate())

Yogesh is right.
GETDATE() gives the present DATEIME value. When you insert it into a DATE column, SQL Server coerces -- silently typecasts -- the DATETIME to a DATE before inserting it.
But when you use it in a WHERE clause, SQL Server coerces the DATE from your column into a DATETIME value by turning 2020-04-20 into 2020-04-20 00:00:00. That can't be the same as GETDATE() except during the first few milliseconds of each day. (Meaning you or your test krewe are extremely unlikely to catch it equal.)

Related

Yesterday into YYYYMMDD format in SQL Server

I'm looking to add in a condition to my already badly performing SQL code. I want to add in a filter where the date = yesterday (data type as INT).
For example
Select *
From table
Where Date = 20190930
How do I do this using GETDATE() - 1?
We need to be very clear about what data type you're using.
If you have a simple date value (no time component as part of the data type), things are pretty easy:
Select *
from table
where Date = DATEADD(day, -1, cast(current_timestamp as date))
If you have a DateTime or DateTime2 value, it's important to understand that all DateTime values have a time component that goes all the way down to milliseconds. This is true even when you expect the time component to always be at or near midnight. That can make straight equality comparisons difficult. Instead, you almost always need check within a specific range:
Select *
from table
where Date >= DATEADD(day, -1, cast(current_timestamp as date))
AND Date < cast(current_timestamp as date)
Here's your query.
Firstly, you need to cast your int date to a varchar before covenrting to datetime, to avoid an arithmetic flow error during conversion.
Secondly, you need to cast getdate() - 1 as date to truncate time to match your date field.
select *
from table
where cast((cast(date as varchar(8))as datetime) = cast(getdate() - 1 as date)
or
select *
from table
where cast((cast(date as varchar(8)) as date) = cast(dateadd(day,datediff(day,1,GETDATE()),0) as date)

SQL WHERE clause to pick data for last 7 days

I want to build a view on the server with a SELECT statement and pick all records that are created at the last 7 days?
Original creation_date field is in varchar like '18/11/08' and I use the CONVERT(datetime, creation_date,11) to convert it into 2018-11-08 00:00:00.000, but I don't know how to do in the WHERE clause, so it only selects all records created for last 7 days.
use where clause like below
select t.* from your_table t
where CONVERT(datetime, creation_date,11)>= DATEADD(day,-7, GETDATE())
In order to get the best performance, you should keep the calculation away from the column:
SELECT *
FROM <YourTable>
WHERE creation_date >= CONVERT(char(8), DATEADD(day,-7, GETDATE()), 11)
This will handle it well because of the format of the varchar - yy/mm/dd. Would not have worked with all formats
The best thing to do is store dates properly to begin with - in a column with a Date data type.
Assuming you can't change the database structure, you can use DateDiff with GetDate():
SELECT <ColumnsList>
FROM <TableName>
WHERE DATEDIFF(DAY, CONVERT(datetime, creation_date,11), GETDATE()) <= 7
Of course, you need to replace the <ColumnsList> with the list of columns and <TableName> with the actual table name.

Please tell me what is error in my date comparison sql query

Please help me to find out error in my SQL query. I have created this query to compare dates
select * from Joinplans jp
where cast(convert(varchar,GETDATE(),103) AS datetime) BETWEEN
CASE(convert(varchar,jp.planstartDate,103) AS datetime) AND
CASE(convert(varchar,DATEADD(DAY,jp.planDays,jp.planstartDate),103) AS DATETIME)
It's giving me the error:
incorrect near 'AS'
I am using SQL Server 2005.
You wrote case instead of cast in two instances.
If planStartDate is actually a date, then there is no need to cast it to a character column:
Select ...
From Joinplans jp
where GetDate() Between planStartDate And DateAdd(day, jp.planDays, jp.planStartDate)
Now, if planStartDate is storing both date and time data, then you might want to use something like:
Select ...
From Joinplans jp
Where planStartDate <= GetDate()
And GetDate() < DateAdd(day, jp.planDays + 1, jp.planStartDate)
This ensures that all times on the last date calculated via the DateAdd function are included

Compare DATETIME and DATE ignoring time portion

I have two tables where column [date] is type of DATETIME2(0).
I have to compare two records only by theirs Date parts (day+month+year), discarding Time parts (hours+minutes+seconds).
How can I do that?
Use the CAST to the new DATE data type in SQL Server 2008 to compare just the date portion:
IF CAST(DateField1 AS DATE) = CAST(DateField2 AS DATE)
A small drawback in Marc's answer is that both datefields have been typecast, meaning you'll be unable to leverage any indexes.
So, if there is a need to write a query that can benefit from an index on a date field, then the following (rather convoluted) approach is necessary.
The indexed datefield (call it DF1) must be untouched by any kind of function.
So you have to compare DF1 to the full range of datetime values for the day of DF2.
That is from the date-part of DF2, to the date-part of the day after DF2.
I.e. (DF1 >= CAST(DF2 AS DATE)) AND (DF1 < DATEADD(dd, 1, CAST(DF2 AS DATE)))
NOTE: It is very important that the comparison is >= (equality allowed) to the date of DF2, and (strictly) < the day after DF2. Also the BETWEEN operator doesn't work because it permits equality on both sides.
PS: Another means of extracting the date only (in older versions of SQL Server) is to use a trick of how the date is represented internally.
Cast the date as a float.
Truncate the fractional part
Cast the value back to a datetime
I.e. CAST(FLOOR(CAST(DF2 AS FLOAT)) AS DATETIME)
Though I upvoted the answer marked as correct. I wanted to touch on a few things for anyone stumbling upon this.
In general, if you're filtering specifically on Date values alone. Microsoft recommends using the language neutral format of ymd or y-m-d.
Note that the form '2007-02-12' is considered language-neutral only
for the data types DATE, DATETIME2, and DATETIMEOFFSET.
To do a date comparison using the aforementioned approach is simple. Consider the following, contrived example.
--112 is ISO format 'YYYYMMDD'
declare #filterDate char(8) = CONVERT(char(8), GETDATE(), 112)
select
*
from
Sales.Orders
where
CONVERT(char(8), OrderDate, 112) = #filterDate
In a perfect world, performing any manipulation to the filtered column should be avoided because this can prevent SQL Server from using indexes efficiently. That said, if the data you're storing is only ever concerned with the date and not time, consider storing as DATETIME with midnight as the time. Because:
When SQL Server converts the literal to the filtered column’s type, it
assumes midnight when a time part isn’t indicated. If you want such a
filter to return all rows from the specified date, you need to ensure
that you store all values with midnight as the time.
Thus, assuming you are only concerned with date, and store your data as such. The above query can be simplified to:
--112 is ISO format 'YYYYMMDD'
declare #filterDate char(8) = CONVERT(char(8), GETDATE(), 112)
select
*
from
Sales.Orders
where
OrderDate = #filterDate
You can try this one
CONVERT(DATE, GETDATE()) = CONVERT(DATE,'2017-11-16 21:57:20.000')
I test that for MS SQL 2014 by following code
select case when CONVERT(DATE, GETDATE()) = CONVERT(DATE,'2017-11-16 21:57:20.000') then 'ok'
else '' end
You may use DateDiff and compare by day.
DateDiff(dd,#date1,#date2) > 0
It means #date2 > #date1
For example :
select DateDiff(dd, '01/01/2021 10:20:00', '02/01/2021 10:20:00')
has the result : 1
For Compare two date like MM/DD/YYYY to MM/DD/YYYY .
Remember First thing column type of Field must be dateTime.
Example : columnName : payment_date dataType : DateTime .
after that you can easily compare it.
Query is :
select * from demo_date where date >= '3/1/2015' and date <= '3/31/2015'.
It very simple ......
It tested it.....

To get date from datetime in sql

I have datecreated field in a table. It contains value as "2009-12-30 11:47:20:297"
I have a query like this:
select *
from table
where DateCreated = getdate()
Although one row exists with today's date, I am not getting that row while executing above query. Can anybody help?
The reason why your query doesn't return the row you expect, is because GETDATE() returns the date and time portion at the moment the query was executed. The value in your DateCreated column will not match the time portion, so no rows are returned.
There are various ways to construct a query so that it evaluates the date based on only the date component. Here's one example:
WHERE YEAR(datecreated) = YEAR(GETDATE())
AND MONTH(datecreated) = MONTH(GETDATE())
AND DAY(datecreated) = DAY(GETDATE())
The unfortunate reality is that any query using a function on the column means that if an index exists on the column, it can't be used.
You can use something like this with Sql Server
CREATE FUNCTION [dbo].[udf_DateOnly](#DateTime DATETIME)
RETURNS DATETIME
AS
BEGIN
RETURN DATEADD(dd,0, DATEDIFF(dd,0,#DateTime))
END
This line
DATEADD(dd,0, DATEDIFF(dd,0,#DateTime))
will strip out the Date portion.
The datetime field includes both the date and the time, accurate to the millisecond. Your query will only work if it is the exact millisecond stored in the database.
To check if it is today, but ignore the time of day, you can check for a range like this:
select * from table where
DateCreated >= '2009-12-30' and
DateCreated < '2009-12-31'
You can use that in conjunction with a function that converts the current date, as astander or Khilon has posted. Here is a full example using astander's answer. Also, as Craig Young points out, this will work with indexes.
select * from table where
DateCreated >= DATEDIFF(dd,0,GETDATE()) and
DateCreated < DATEDIFF(dd,0,GETDATE())
The simplest solution might be :
SELECT CAST(GETDATE() as DATE)
You can convert datetime to a string with only the date by using
CONVERT(varchar(8), GETDATE(), 112)
If needed, you can then change it back to datetime and as a result you'll get a datetime with the hours, minutes, seconds and milliseconds set to zero.