115

I have a table with dates that all happened in the month November. I wrote this query

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
created_date <= '2013-04-12'

This query should return everything that happened in month 11 (November) because it happened before the date '2013-04-12' (in December)

But it's only returning available dates that happened in days lesser than 04 (2013-04-12)

Could it be that it's only comparing the day part? and not the whole date?

How to fix this?

Created_date is of type date

Date format is by default yyyy-dd-MM

16
  • 1
    You are comparing dates to strings, not dates to dates Commented Nov 12, 2013 at 8:28
  • 4
    Maybe it thinks 2013-04-12? is April 12th? Or maybe created_dateis a string and not a date?
    – jpw
    Commented Nov 12, 2013 at 8:28
  • Look at Cast & Convert on T-SQL manual and use the appropriate conversion for your locale
    – Steve
    Commented Nov 12, 2013 at 8:30
  • 3
    No need to cast at all, just use the invariant format '20130412' Commented Nov 12, 2013 at 8:31
  • 1
    Instead of sending a string with the date then, try creating a parameterized query and pass the date as a date-typed parameter. BTW what version of SQL Server are you using? DATE was added in SQL Server 2008. Commented Nov 12, 2013 at 10:55

12 Answers 12

113

Instead of '2013-04-12' whose meaning depends on the local culture, use '20130412' which is recognized as the culture invariant format.

If you want to compare with December 4th, you should write '20131204'. If you want to compare with April 12th, you should write '20130412'.

The article Write International Transact-SQL Statements from SQL Server's documentation explains how to write statements that are culture invariant:

Applications that use other APIs, or Transact-SQL scripts, stored procedures, and triggers, should use the unseparated numeric strings. For example, yyyymmdd as 19980924.

EDIT

Since you are using ADO, the best option is to parameterize the query and pass the date value as a date parameter. This way you avoid the format issue entirely and gain the performance benefits of parameterized queries as well.

UPDATE

To use the the the ISO 8601 format in a literal, all elements must be specified. To quote from the ISO 8601 section of datetime's documentation

To use the ISO 8601 format, you must specify each element in the format. This also includes the T, the colons (:), and the period (.) that are shown in the format.

... the fraction of second component is optional. The time component is specified in the 24-hour format.

3
  • @andy not exactly, the ISO8601 format includes the time element. Or as the docs say, To use the ISO 8601 format, you must specify each element in the format. This also includes the T. Commented Sep 11, 2015 at 8:17
  • 1
    Sorry for being unclear, my point was that ISO8601 defines the order just the way you described: YYYY-MM-DD or for short YYYYMMDD. However, as the docs also state: "datetime is not ANSI or ISO 8601 compliant.". The ISO itself would not require a time part.
    – andy
    Commented Sep 11, 2015 at 8:27
  • What you refer to doesn't change the fact that YYYY-MM-DD is not recognized as ISO 8601. The time parts are required. Call it T-SQL's strangeness if you will, or incomplete implementation. It may even be that this was carried over from Sybase Commented Sep 11, 2015 at 8:32
38

Try like this

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
created_date <= '2013-12-04'
7
  • 9
    Culture specific format. Is that 12 April or 4 December? The dash-separated format is NOT the international format Commented Nov 12, 2013 at 8:37
  • 2
    So what happens when you need to store data from international clients? Or the date comes from a web browser which follows the user's culture? The guidelines exist for a reason, and by simply NOT using the wrong format, you avoid all errors Commented Nov 12, 2013 at 8:42
  • 2
    @Nithesh This is returning April 12th Commented Nov 12, 2013 at 8:44
  • 28
    @PanagiotisKanavos The dash-separated format is the international format ever since ISO 8601 was published in 1988. Other formats are discouraged and ridiculed. Even the article you posted, "Write International Transact-SQL Statements" never once identifies 'yyyymmdd' as any kind of "international" standard.
    – Jesse Webb
    Commented Jul 17, 2014 at 17:50
  • 2
    Adding single quotes around the date resolved this for me. Was using format 2/19/2015. Changed to '2/19/2015' and it started working. Thanks for the simple idea.
    – Ethan Turk
    Commented Feb 19, 2015 at 21:26
17

If You are comparing only with the date vale, then converting it to date (not datetime) will work

select id,numbers_from,created_date,amount_numbers,SMS_text 
 from Test_Table
 where 
 created_date <= convert(date,'2013-04-12',23)

This conversion is also applicable during using GetDate() function

-- Updating cast number as per the suggestion of @Thomas853

1
5

please try with below query

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
convert(datetime, convert(varchar(10), created_date, 102))  <= convert(datetime,'2013-04-12')
5

You put <= and it will catch the given date too. You can replace it with < only.

2

Convert them to dates in the same format and then you can compare. Τry like this:

where convert(date, created_date,102) <= convert(date,                                  /*102 is ANSI format*/
                                                    substring('2013-04-12',1,4) + '.' + /*year*/
                                                    substring('2013-04-12',9,2) + '.' + /*month*/
                                                    substring('2013-04-12',6,2)         /*day*/
                                                ,102)
1

Date format is yyyy-mm-dd. So the above query is looking for records older than 12Apr2013

Suggest you do a quick check by setting the date string to '2013-04-30', if no sql error, date format is confirmed to yyyy-mm-dd.

0
1

Below query can be used to find the records of month November for the year 2013.

Select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where Month(created_date) = 11 and Year(created_date) = 2013
1

Test_Table.created_date is a date/time type field.

'2013-04-12' is a string constant.

To compare two values they need to be the same type. The efficient way to do that is to convert the string constant to a date/time constant using a function. (It's far more efficient to convert a constant once and compare that against the stored value than to convert every single stored value a string so you can compare it to another string.)

What that function is depends on what database you're using. For instance, I am using an Apache Impala database, and it uses TO_TIMESTAMP() to convert a string to a timestamp:

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
created_date <= to_timestamp('2013-04-12', 'yyyy-MM-dd')

Oracle and Postgres also use to_timestamp() but they use different date format strings. Oracle and Postgres would use 'YYYY-MM-DD' in the above example.

MySQL and MariaDB use the STR_TO_DATE() function and an entirely different way to specify date formats.

In general just Google "my database name" + "string to date format" and you'll find the date function and date format for your database.

0

Try to use "#" before and after of the date and be sure of your system date format. maybe "YYYYMMDD O YYYY-MM-DD O MM-DD-YYYY O USING '/ O \' "

Ex:

 select id,numbers_from,created_date,amount_numbers,SMS_text 
 from Test_Table
 where 
 created_date <= #2013-04-12#
0

For my queries on MS Access, I can compare dates with this syntax:

SELECT COUNT(orderNumber) AS Total
FROM Orders
WHERE orderDate >=#2003/04/01#
AND orderDate <=#2003/06/30#;

Where the output is the number of orders between 2003-04-01 and 2003-06-30.

-1

you can also use to_char(column_name, 'YYYY-MM-DD) to change format

1

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