简体   繁体   中英

Query comparing dates in SQL

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

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

Try like this

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

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',102)

This conversion is also applicable during using GetDate() function

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

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')

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#

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.

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)

您还可以使用 to_char(column_name, 'YYYY-MM-DD) 更改格式

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

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM