CONVERT (Data_type,expression[,style])CONVERT (varchar (10), field name, conversion format)DescriptionThis style is typically in the time type (Datetime,smalldatetime) and the string type (Nchar,nvarchar,char,varchar)It is only used when converting
Research on the null values of datetime type in SqlServer and the null values of DateTime in c # In SqlServer2000: The default value is 1900-01-0100:00:00, in C #, the null value of DateTime is the minimum value of 0001-01-0100:00:00. For database
Use convert in SQL server2000 to get the datetime data type style (full)Processing of date data formats, two examples:CONVERT (varchar (16), time one, 20) results: 2007-02-01 08:02/* time is generally a field in the GETDATE () function or data table
Common date functions
SQL Server time and date function detailed, SQL Server, time, date,
1. Current system date, time
Select GETDATE ()
2. DateAdd returns a new datetime value on the basis of adding a period of time to the specified date
For
Reproduced in this blog, the original blog: http://blog.csdn.net/baiduandxunlei/article/details/9180075CONVERT (Data_type,expression[,style])CONVERT (varchar (10), field name, conversion format)DescriptionThis style is typically in the time type
Using date types in PL/SQLThe previous article described the use of strings and numbers in PL/SQL. There is no doubt that strings and numbers are important, but you can be sure that no application is dependent on the date.You need to record events,
1. calculate the maximum number of days of calendar month. getinstance (); time. clear (); time. set (calendar. year, year); // year is inttime. set (calendar. month, I-1); // note that the default January Calendar Object is 0 int day = time.
SQL statement gets a specific date
1. The first day of one months
Select DATEADD (mm, DATEDIFF (Mm,0,getdate ()), 0)
2. Monday of this week
Select DATEADD (wk, DATEDIFF (Wk,0,getdate ()), 0)
3. The first day of the year
Select DATEADD (yy,
Processing of date data formats, two examples:CONVERT (varchar (16), time one, 20) results: 2007-02-01 08:02/* time is generally a field in the GETDATE () function or data table */CONVERT (varchar (10), time one, 23) Result: 2007-02-01/*varchar (10)
When it comes to the date and time functions in SQL, we have to come up with the following two concepts: deterministic and non-deterministic functions.
Deterministic function: the obtained value is in a set of established values, or can be expected.
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.