yeardiff in mysql. Based in the answer from dbdemon, you could use a CASE: CREATE TABLE t1 ( id int unsigned primary key, date1 date, date2 date ); INSERT INTO t1 (id, date1, date2) VALUES (1, '2017-12-29', '2018-01-05'), (2, '2018-02-20', '2018-03-05'); SELECT. yeardiff in mysql

 
 Based in the answer from dbdemon, you could use a CASE: CREATE TABLE t1 ( id int unsigned primary key, date1 date, date2 date ); INSERT INTO t1 (id, date1, date2) VALUES (1, '2017-12-29', '2018-01-05'), (2, '2018-02-20', '2018-03-05'); SELECTyeardiff in mysql MySQL DATEDIFF() returns the number of days between two dates or datetimes

DATEDIFF in MySQL query. answered Jan 27, 2011 at 22:04. Introduction. Finding the seconds difference can be done as follows: SELECT (mod_date_time - create_date_time) * 24 * 60 * 60 as "seconds_diff" FROM t1. Select datediff (max (hire), min (hire)) as Difference From Employees Where terminated = 'NULL'. 0. To get the difference in seconds as we have done here, choose SECOND. While SQL is a programming language used to work with data in relational databases, MySQL is an open-source database product that implements the SQL standard. Date Part Flexibility: Years, months, days, hours, minutes, and seconds are among the date parts that are supported. for more on date functions MySQL documentation. 17. The date to be formatted. The DATEDIFF takes two arguments as shown in the example below: 1. The MySQL PASSWORD function is used for the generation of a hashed password using a plain-text password string It uses hashing techniques to generate the hashed password. The following MySQL WHERE IN query gives rows where membership_number is either 1 , 2 or 3. Date values are interpreted as DateTime with the time part set to 00:00:00 by default. See the following example:Try the below SQL QUERY for finding Year difference between two dates using DATEDIFF function. Days; This is possible via operator overloading. It will give you exact age in years. To get the difference in hours, choose. sql. 7 Reference Manual :: 12. First, take the inner DATEDIFF portion. 5+. Penanganan tanggal dan waktu merupakan hal yang cukup penting dalam suatu software basis data, termasuk MySQL. Follow answered Dec 1, 2009 at 21:26. In MySQL, DATEDIFF function, takes only two arguments: end date and start date: DATEDIFF(NOW(), P. 1. If the year diff has to be counted this way then use: EXTRACT (YEAR FROM date_to) - EXTRACT (YEAR FROM date_from) Just. ;. Parameter 2 - Begin Date or Datetime Values. The output is then either a. Date or DateTime could be one of them. Database. e. Alternatively, you can use TIMEDIFF (ts1, ts2) and then convert the time result to seconds with TIME_TO_SEC (). 1. DATEDIFF () FUNCTION. Specifically, it gets the difference between 2 dates with the results returned in date units specified as years, months days, minutes, seconds as a bigint value. When analyzing historical data, DATEDIFF () helps quantify the time. The DATE, DATETIME and TIMESTAMP datatypes in MySQL are used to store the date, date and time, time stamp values respectively. Q&A for work. (In our example, it’s the expiration_date column. For up to date solution see jurkas' answer above. For this, you need to: Click Comparison > New Data Comparison. I would recommend using 365. For both DATEDIFF and minus sign: Output values can be negative, for example, -12 days. Examples below. This effectively means that MySQL date-functions are useless to you. 5, MySQL 5. When one of your statements fails, you can undo all previous changes from the start of the transaction just by running the ROLLBACK statement. Parameter 1 - unit, it is a type of output you want, such as MICROSECOND, SECOND MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, YEAR. mysql> SELECT DATE('2003-12-31 01:02:03'); -> '2003-12-31' DATEDIFF(expr1,expr2) DATEDIFF() returns expr1 − expr2 expressed as a value in days from one date to the. It is commonly deployed as part of the LAMP stack (which stands for Linux, Apache, MySQL, and PHP) and, as of this writing, is the most popular open-source database in the world. UNIX_TIMESTAMP (ts1) - UNIX_TIMESTAMP (ts2) If you want an unsigned difference, add an ABS () around the expression. MySQL - how to dynamically add columns with subquery in Select clause based on date range. MySQL is free and open-source. 25 for the days in the SQL DateDiff function to avoid issues with leap year. The way it works is, you provide two arguments (one for each date), and DATEDIFF() will return the number of days between the two dates. Description. 引数は、結果を表す単位と、差異を取る 2. The format to use. sql. how to count mysql records for each month of the year grouped by one field. This seems to work for all the dates I throw at it. WARNING: An ideal function would be aware of leap years and days count in every month, but I found the. As of MySQL 8. MySQL provides a set of functions to. The WHERE clause can be combined with AND, OR, and NOT operators. DEMO: Select date from Calendar to execute YEAR () →. 2 Answers. UNIT can be SECOND MINUTE HOUR DAY WEEK. They are grouped into five main categories: Numeric data types. MySQL Database: Restore Database. TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS. SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2;EXPLANATION: In this example, the MySQL DATEDIFF() function calculates the number of days between the two dates 2023-03-07 and 2023-03-01, but with an interval adjustment. MySQL DATEDIFF is used to find the difference between the specified dates. Difference will be calculated as startdate - enddate . The MySQL PERIOD_DIFF function returns the difference in months between two periods (formatted as YYMM or YYYYMM). The MySQL TIMEDIFF() function returns the difference between two time or datetime values. SELECT log, TIMESTAMPDIFF(year, createddate, waitingtime) AS YearDiff, TIMESTAMPDIFF(month, createddate, waitingtime) AS. How many days are there in a year? It's certainly not always 365. 2). W3Schools offers free online tutorials, references and exercises in all the major languages of the web. *. Example. 3 - First day of week is Monday and the. ) to use for determining the difference. Detailed instructions, as well as other methods for installation, can be found in Installing MySQL on Linux. e. DATEDIFF in MySQL query. The accepted answer didn't work for me in MySQL 5. Another simple way to cast the string to dateType in spark sql and apply sql dates and time functions on the columns like following : . In MariaDB, DATEDIFF () is a built-in date and time function that returns the difference, in days, between two dates. SELECT year (dt2) FROM `dt_tb`. Can be one of the following: 0 - First day of week is Sunday. So if there are two dates separated by one day, the year difference can be 1 (see select datediff (year, '20141231', '20150101') ). When you query data from a DATETIME column, MySQL displays the DATETIME value in the following format: YYYY-MM-DD HH:MM:SS Code language: SQL (Structured Query Language) (sql) By default, DATETIME values range from 1000-01-01 00:00:00 to 9999. SubscrpEndDate__c) AS 'SubscriptionDueDate'. 5 Answers. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. You use MySQL DATETIME to store a value that contains both date and time. MySQL DATE_ADD() Function MySQL Functions. Date functions give you numerous options on how to modify, calculate, and convert date, time, and datetime expressions in MySQL. The unit argument can be MICROSECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR. I left the output in Italian. The DATEDIFF () function calculates the difference in days between two DATE values. Without using the DATE () function, then MySQL will also compare the time portion of the column with your string expression. Gets the number of intervals between two DATE values. i've tried. Difference between OLTP and Inmon Data Warehouse. Microsoft Windows. Possible duplicate of Only show hours in MYSQL DATEDIFF – Sebastian Brosch. 1. MySQL is an open-source relational database management system. In this article, we focused on differences between time periods, but window. MySQL 8. I'm trying to obtain the age of companies in years months and days, however the calculation its not right. YEARS AS VARCHAR ) + ' Anni ' ELSE '' END + CASE WHEN. As we can see in the result, we got only two rows in which the names start with the letter “j”. So, we can use the TIMEDIFF() function with time values greater than 24 hours. The DATE, DATETIME and TIMESTAMP datatypes in MySQL are used to store the date, date and time, time stamp values respectively. Handling dates is tricky. MySQL comes with many built-in functions that allow you to manipulate data. 6. Create function get_Exact_Date_diff (@date smalldatetime,@date2 smalldatetime) returns varchar (50) as begin declare @date3 smalldatetime Declare. The basic query with MYSQL table is here. Subtracts the 2nd argument from the 3rd (date2 − date1). (05-10 to 05-31) = 21 days (2014-06 to 2015-03) = 9 months (03-01 to 03-09) = 9 days total is 9 months and 30 days. We will use the below date for the examples. For VB fans, you can reference the Microsoft. DATEDIFF () FUNCTION in MySQL. TIMESTAMP - format: YYYY-MM-DD HH:MI:SS. spark. e keys identify the rows by combining one or more columns. The MySQL DATEDIFF function is used to get the difference in days between two date values. Date or DateTime could be one of them. DATE_ADD. For example, if we want to know the difference between two dates in seconds: SELECT id, job, TIMESTAMPDIFF(SECOND, start_date, end_date) AS runtime FROM example_table; This calculates end_date - start_date in seconds. As for comparing, you could compare dates that are the first days of those years and months, or you could convert the year/month pair into a number suitable for comparison (i. 参考:mysql 12. Introduction to MySQL PERIOD_DIFF () function. 6. Week where Monday is the first day of the week (01 to 53). 5+ and MariaDB 5. The GROUP BY clause with aggregate function makes the result within a group. DATE_FORMAT () Format date as specified. MySQL provides a set of functions to. 2 - First day of week is Sunday. I use $_POST in php to send this to a CHAR(6) field in MySQL How do I then simply echo the age (as of today, in years only) in 1) the same html window after the person types it in, and 2) in a separate html page by retrieving form data from MySQL?MySQL SQL MySQL SELECT MySQL WHERE MySQL AND, OR, NOT MySQL ORDER BY MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN and MAX MySQL COUNT, AVG, SUM MySQL LIKE MySQL Wildcards MySQL IN MySQL BETWEEN MySQL Aliases MySQL Joins MySQL INNER. I want the difference between the times to display something like: 1d 2h 23m. Functions are based on a date-time serial number that equals the number of days since December 30, 1899. That is SQL Server syntax for converting a date to a string. Here is an example that uses date functions. 4. The difference between startdate and enddate is expressed in days. dbForge Studio for MySQL. Add 10 days to a date and return the date: SELECT DATE_ADD("2017-06-15", INTERVAL 10. This can be the name of a date/datetime/timestamp column or an expression returning one of those data types. The two expressions don’t have to be of the same type. date: This is the date or datetime value from which you want to get the year. Takes three arguments, the start date. In this article we cover the concept of a transaction, MySQL and the ACID Model, MySQL Transaction, statements that cannot be Rolled Back and cause an implicit Commit, SAVEPOINT, ROLLBACK TO SAVEPOINT, and RELEASE. Full years between start_date and end_date, and. This MySQL tutorial explains how to use the MySQL PERIOD_DIFF function with syntax and examples. You signed out in another tab or window. In MySQL, the DATEDIFF() function is a powerful tool for working with date and time data. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. Let us see how to use this MySQL TIMESTAMPDIFF function to find the difference in Year, Months, Days, Hours, etc. Then when you call with: select * from dbo. It allows you to calculate the difference between two dates in days, making it incredibly useful for a variety of. Timestamp): return 366 if date. For example, if you want to calculate the number of hours between two times, you can use the following SQL query: SELECT DATEDIFF (hour, '2022-01-01 12:00:00', '2022-01-01 14:30:00') AS HourDiff; This query will return the number of hours between 12:00 PM and 2:30 PM on January 1, 2022, which is 2. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. MySQL SQL MySQL SELECT MySQL WHERE MySQL AND, OR, NOT MySQL ORDER BY MySQL INSERT INTO MySQL NULL Values MySQL UPDATE MySQL DELETE MySQL LIMIT MySQL MIN and MAX MySQL COUNT, AVG, SUM MySQL LIKE MySQL Wildcards MySQL IN MySQL BETWEEN MySQL Aliases MySQL Joins MySQL. This function only calculates the date portion from each expression. is_leap_year else 365 def num_years (start_date:. Only the date parts of the values are used in the calculation. . expr1 and expr2 are date or date-and-time expressions. 6, MySQL 5. MYSQL에서 DATEDIFF, TIMEDIFF 를 이용해 날짜 및 시간을 계산해보기로 합니다. Year-over-year (YOY) comparisons are a popular and effective way to evaluate the performance of several kinds of organizations. C. What I'am doing wrong The messure is the folowing YearMonths = VAR Days = DATEDIFF(max('produccion agency'[hire_date]),TODAY(),DAY) VAR Months = ROUNDDOWN(Days/31,0) VAR Years = ROUNDDOWN(Mo. DATEDIFF() or BETWEEN for Date Ranges in SQL Queries. Here’s the syntax of the PERIOD_DIFF () function: PERIOD_DIFF (P1, P2) Code language: SQL (Structured Query Language) (sql) In this syntax: P1: The first period (in the format. This should only happen in the first week of the year and the last week of the year. SSS, which is not the case with your date. Where a time stamp is a numerical value representing the number of milliseconds from '1970-01-01 00:00:01' UTC (epoch) to the specified time. In SQL SERVER, you can use the following query (replace the date with your field): SELECT CASE WHEN datediff (year, '20120303', getdate ()) > 1 THEN datediff (year, '20120303', getdate ()) ELSE datediff (day, '20120303', getdate ()) END AS Diff. ) how to calculate mysql date diff between two dates excluding Fridays and Saturdays as Fridays and Saturdays are off days. The TIMESTAMPDIFF function returns the result of begin - end, where begin and end are DATE or DATETIME expressions. 6222691' DECLARE @date2 datetime2 = '2022-01-14 12:32:07. We need to remember about special cases: leap seconds, different timezones etc. The TIMESTAMPDIFF() function will then return the difference in the specified unit. Stack Exchange Network. The following query selects all rows with a date_col value from within the last 30 days: . The main problem is as follows: In order to find the difference between days you need to use datediff(); datediff() returns the difference in days. The datepart argument can be microsecond, second, minute, hour, day, week, month, quarter, or year. DATE_SUB () Subtract a time value (interval) from a date. You can only store dates as numbers or text. Here expr2 is greater than expr1, so the return value is positive. sql. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. 0. TIMESTAMPADD () This function adds an interval to a datetime expression. Follow answered Feb 14,. Syntax:datediff function. select DATEADD(MONTH,1350,0) will give 2012-07-01 00:00:00. Dim TheDate As Date ' Declare variables. , with an example. MySQL recognizes DATE , DATETIME, and TIMESTAMP values in several formats, described in Section 9. SELECT ((DATEDIFF('2022-01-02', '2021-12-30'))+1 - ((WEEK('2022-01-02') - WEEK('2021-12-30')) * 2) - (case when weekday('2022-01-02') = 5 then 1 else 0 end) - (case when weekday('2021-12-30') = 4 then 1 else 0 end)) as DifD but it gives wrong count (105 days. end_date: The date to which you want to calculate the difference. start_date: The date from which you want to calculate the difference. At any rate, try this: WHERE specific_date <= DATE_ADD (NOW (), INTERVAL 5 DAY) This is a good way to do such a lookup. Any dates entered with a year value less than or equal to the cutoff year are considered to be in the current century, while those greater. How to count total by current year of current month in mysql. MySQL Dates between Dates. For example: Check in date is 12-04-2010 Check out date 15-04-2010 The day difference would be 3. There are no user contributed notes for this page. Based in the answer from dbdemon, you could use a CASE: CREATE TABLE t1 ( id int unsigned primary key, date1 date, date2 date ); INSERT INTO t1 (id, date1, date2) VALUES (1, '2017-12-29', '2018-01-05'), (2, '2018-02-20', '2018-03-05'); SELECT. 68 sec) Insert values for all fields using insert command. If you omit the password value following the --password or . Syntax. inner select select DATEDIFF(MONTH, 0, GETDATE()) will give the number of months from 1900-01-01 here it is 1350. Apr 4, 2018 at 6:36. This MySQL tutorial explains how to use the MySQL DATEDIFF function with syntax and examples. One may be a date and another is datetime. String data types. To specify common table expressions, use a WITH clause that has one or more comma-separated subclauses. I pull 5 days ago data from mysql i want to name the folder the date from 5 days ago. Return the difference between two time expressions: SELECT TIMEDIFF("13:10:11", "13:10:10");Have a look at the TIMESTAMPDIFF() function in MySQL. The DATE_ADD function adds an interval to a DATE or DATETIME value. In addition to calculating the. We learned how to get work orders that took longer, get the oldest employees, the time between the. And most of the time, this will require calculating the number of days between date values. startdate: The starting datetime value. 7 Answers. October 10, 2023. YEARWEEK () Function in MySQL. The number of days is calculated using the MySQL DATEDIFF () function. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Below is the example that returns a difference of two date values, 2020-03-01 and 2020-03-10, in days: Query: select timestampdiff(day,'2020-03-01', '2020-03-10') AS result; Output:The value I would actually like to be seen selected out is the years it has been released as a decimal number (up to 1 decimal point), so it would show the age such as (ex. Tom H Tom H. Edit the SQL Statement, and click "Run SQL" to see the result. Week where Monday is the first day of the week (01 to 53). You can just subtract datetimes and it will return the value: select (now () - interval 2 day) - (now () - interval 5 day); The result isn't a datetime (it's some decimal coded date -- 3000000 for three days in this case), but it isn't correct to say consider a datetime and an interval as the same datatype. The general form for the DATEDIFF is. firstdayofweek. frame (now, now2) sqldf ("select now2 - now as dif from DF2. Date/Time Functions. Set @monthDiff = ABS(DATEDIFF(MONTH, @FromDate, @ToDate)%12) Set @yearDiff = ABS(DATEDIFF(YYYY, @FromDate, @ToDate)) -- If the From date month is greater than the month of the To date and the year. 2 Compare and Report Differences in Catalogs. If the date is NULL, the YEARWEEK () function will return NULL. The BETWEEN operator selects values within a given range. I need to find how many months there are within these two days. The following query selects all rows with a. In the above example, the CURDATE () function took the. To find out your SQL Server start of the week you can use @@DATEFIRST by running this: select @@DATEFIRST -- default US English = 7 (Sunday) You could change your calculation to work on days rather than weeks and dividing by 7 to get a more accurate value, which you can round as you please: MySQL: SQL Fiddle Demo. DATEDIFF does not guarantee that the full number of the specified time units passed between 2 datetime values: -- Get difference in hours between 8:55 and 11:00 SELECT DATEDIFF (hh, '08:55', '11:00'); -- Returns 3 although only 2 hours and 5 minutes passed between times -- Get difference in months between Sep 30, 2011 and Nov 02, 2011. Support modern cloud applications with Azure SQL. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. store the user birthday format like this. runTime, INTERVAL 20 MINUTE) < NOW () NOTE: this should work if you're using MySQL DateTime format. Each DateTime instance refers to a specific millisecond of the Unix epoch. Once done, we will shift focus from date to. When you query data from a DATETIME column, MySQL displays the DATETIME value in the following format: YYYY-MM-DD HH:MM:SS Code language: SQL (Structured Query Language) (sql) By default, DATETIME values range from 1000-01-01 00:00:00 to 9999-12-31 23:59:59. e. UNIT can be SECOND. The MySQL PERIOD_DIFF () function is used to return the difference between two periods. If you prefer short options, the command looks like this: $> mysql -u finley -p db_name. It is to be noted that two expressions must be the same type. Date with caution. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. If you want use aggregation. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. If the value of basis is AGE, then YRDIF computes the age. MySQL Data Types. For DATEDIFF: date_or_time_expr1 and date_or_time_expr2 can be a date, time, or timestamp. The next example will show the differences between two dates for each specific datapart and abbreviation. 1. Mysql PERIOD_DIFF () Function. A time zone. firstdayofweek. 1. Both. Otherwise, it returns value of year which range from 1000 to 9999 and value of week which ranges between 0 to 53. Datediff Function in MySQL Concept. If I understand your comments on the previous answers, the date-of-birth column is not actually a DATE value but a string in the format m/d/y. MySQL には、年齢の計算や日付の一部の抽出など、日付の計算に使用できる関数がいくつか用意されています。. Di tutorial ini, saya tidak akan membahas satu per satu. This example uses the DateDiff function to display the number of days between a given date and today. e. MySQL Database: Restore Database. The difference between startdate and enddate is expressed in days. 48. The result returned is the number of months between those periods. Introduction. The TIMESTAMPDIFF function allows its arguments to have mixed types e. 定义和用法. If this solutions doesn't work, you can still try using add_months () and multiply your desired number of years by 12 to add the correct number of months. Another argument provides the unit for the result. 25) as 'years-count' from mytableofdates. Consider there are 44 days between two dates. Here's what that query would look like in Navicat: To convert the rental_date from a datetime to a pure date we can use the DATE () function. 3, “Date and Time Literals”. Introduction to MySQL DATE_ADD function. To determine how many years old each of your pets is, use the TIMESTAMPDIFF () function. DATEDIFF() or BETWEEN for Date Ranges in SQL Queries. Arguments. 0. I see the result as below. If both operands are integers and any of them are unsigned, the result is an unsigned integer. Functions that expect time values usually accept datetime values and ignore the date part. Here is the main query to get the year part from MySQL date and time field. The MySQL DATEDIFF () function takes two dates and returns the number of days between them. 1. In this article: Syntax. What you need to do is convert it into valid format. 0. SELECT start_time ,end_time ,DATEDIFF(end_time, start_time) ASMySQL Database: Restore Database. 1. The column value stands alone on one side of the inequality predicate (the <=) so mySQL can do an index range scan if you have an index on the column. Bahkan MySQL memiliki lebih dari 50 fungsi khusus berhubungan dengan tanggal dan waktu. Use the DateDiff function in VBA code. I updated the query to work for me: select * from (select adddate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) selected_date from (select 0 t0 union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0. 14+ and the mode is not specified, the YEARWEEK function will use the value in the default_week. The MySQL DATEDIFF () function allows you to count the number of days between two different date expressions. montant / (datediff (NEW. You'll always know which days are weekdays and weekends with a. e. In MySQL, you can use the DATEDIFF() function to find the difference between two dates. If you are running MySQL 4. MySQL Examples MySQL Examples MySQL Editor MySQL Quiz MySQL Exercises MySQL Certificate. I need to get the difference between a definite time everyday say 12. For the DATE and DATETIME range descriptions, “supported” means that although earlier values might work, there is no guarantee. For example, you can use: SELECT TIMESTAMPDIFF (SECOND, '2012-06-06 13:13:55', '2012-06-06 15:20:18') In your case, the third parameter of TIMSTAMPDIFF function would be the current login time ( NOW () ). Asking for help, clarification, or responding to other answers. julianday(1643024886, 'unixepoch'). numeric (dif)) sqldf ("select * from DF1") ## dif ## 1 1. One expression may be a date and the other a datetime; a date value is treated as a datetime having the time part '00:00:00' where necessary. It's a useful function for performing date-based calculations and obtaining insights into the duration between two points in time. Here, you'd like to get the difference in seconds, so choose second. This will collect the year part from the field. MySQL Examples MySQL Examples MySQL Editor MySQL Quiz MySQL Exercises MySQL Certificate. Here’s the syntax of TIMEDIFF () function: TIMEDIFF (time1, time2); Code language: SQL (Structured Query Language) (sql) In this syntax: time1: The first TIME or DATETIME value. You'll get a more accurate result if you compute the difference between the two dates in days and divide by the mean length of a calendar year in days over a 400 year span (365. One way is to split it and pass into the constructor like this: let dob_string = "DOB: 14/09/2016"; let dl_string = "Download Date: 03/11/2020"; let dob =. And you are trying to pass a formatted date string. The DATEDIFF function has two arguments; we specify the dates for which we want to find the difference. MySQL PERIOD_DIFF () returns the difference between two periods. Here’s a quick rundown of the functions you can use in MySQL:. 6. MySQL DATEDIFF () returns the number of days between two dates or datetimes. mysql> SELECT something FROM tbl_name-> WHERE DATE_SUB(CURDATE(),INTERVAL 30 DAY) <= date_col;. Its arguments are the unit in which you want the result expressed, and the two dates for. DBDiff is an automated database schema and data diff tool. dbForge Studio for SQL Server. Get your own SQL server SQL Statement: Edit the SQL Statement, and click "Run SQL" to see the result. Consider SQL Server function to calculate the difference between 2 dates in months: SQL Server : -- Difference between Oct 02, 2011 and Jan 01, 2012 in months SELECT DATEDIFF ( month, '2011-10-02', '2012-01-01') ; -- Result: 3.