datediff function in sql

Deep Learning of SQL Server aggregate function algorithm optimization skills, SQL server Aggregate functions are widely used in practical work to cope with various needs. Optimization of Aggregate functions naturally becomes a key point, whether a program is optimized or not directly determines the statement cycle of the program.

Sometimes a partition function is built on the job, but a partition function like a date can have a value of hundreds of if it's not going to kill me. So I wrote a bit of code to automatically generate a monthly partition function and a corresponding partition theme starting from 1990. Use [TestDB]GODECLARE @STR NVARCHAR(MAX)SET @STR = 'CREATE PARTITION

Create function todayCREATE FUNCTION ' func_get_split_string_total ' (f_string varchar (+), F_delimiter varchar (5)) RETURNS Int (one) BEGIN return 1+ (Length (f_string)-Length (replace (F_string,f_delimiter, '))); ENDError message:ERROR 1418 (HY000): This function has none of the deterministic, NO SQL, or READS

Copy Code code as follows: ALTER FUNCTION [dbo]. [Get_fullage] ( @birthday datetime, @currentDay datetime ) RETURNS INT As BEGIN DECLARE @age INT SET @age = DATEDIFF (year, @birthday, @currentDay) IF DATEDIFF (DATEADD (year, @age, @birthday), @currentDay) SET @age = @age-1 IF DATEPART (MONTH, @birthday) = 2 and DATEPART (day, @birthda

Server SQL Server 2000 Log shipping Function-settings (1) The log shipping feature automatically copies the transaction log file for the database and is saved to another database in the standby server (standby server). Therefore, the availability of SQL Server databases can be greatly improved. Because the standby database completely receives the variance of the

Tags: identifying group numeric connections Count Sum compression nbsp calculationConnection Query Inner JOIN, with the most, representing more than one table one by one corresponding Aggregation functions Manipulating row data, merging Sum, AVG, COUNT, Max, min Open Window function Distributes the merged data to each row of the original table, which is the equivalent of a column that may be the sum of sums, or the val

-theme-font: minor-latin; mso-fareast-font-family:; mso-fareast-theme-font:Minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin "> give Randmso-ascii-theme-font: minor-latin; mso-fareast-font-family:; mso-fareast-theme-font:Minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin "> the function transmits a non-linear value. The first thought is to use an exclusive or operation. What is the exclusive

Tags: simplification--com result sequence subroutine find BER printPL/SQL functionsThe PL/SQL function is the same as the procedure, except that the function has a return value. Therefore, all the discussions in the previous chapters apply to the function.Create a functionEstablishing a standalone

PL/SQL single-row functions and group functions A function is a program with zero or multiple parameters and a return value. Oracle has a series of built-in functions in SQL, which can be called SQL or PL/SQL statements. functions are mainly divided into two categories:Singl

1. Day (date_expression)Returns the date value in Date_expression2. Month (date_expression)Returns the month value in Date_expression3. Year (date_expression)Returns the year value in Date_expression4, DATEADD ()DATEADD (Returns the new date specified by date plus the specified extra date interval number.5, DATEDIFF ()DATEDIFF (Returns the DATEPART difference between the two specified dates, that is, the da

SQL Server user-defined Function usage, sqlserverfunction I. FUNCTION:In sqlserver2008, there are 3 custom functions: scalar functions, inline table valued functions, and multi-statement table valued functions. First, summarize the similarities and differences of their syntax: Similarities:1. the creation definition is the same: a, create function F_NAME (type of

:00.000 Select DATEADD (qq,12, ' 1990-12-11 ') Back to 1993-12-11 00:00:00.000 Select DATEADD (hh,12, ' 1990-12-11 ') Back to 1990-12-11 12:00:00.000 Select DATEADD (yy,-12, ' 1990-12-11 ') Back to 1978-12-11 00:00:00.000 Returns a new date value that is added to the specified date after a time interval. Number: The value that is used to add to the specified date part. If a non-integer value is specified, The decimal portion of the value is discarded, and rounding is not followed when it is disc

Reprint Address: http://blog.csdn.net/dba_huangzj/article/details/8300784#Directory First look at the brief definition of Books Online Grammar Here are a few more useful examples First take a look at how this function is used on MSDN COALESCE function returns a value that is not NULL in a parameter, such as Then take a look at applying the

, cast (expression as data_type), example: Select substring (title, 1, 30) as title, ytd_sales from titles where cast (ytd_sales as char (20 )) like '3% 'convert (data_type, expression) 3. date functions Day (), month (), Year () dateadd (datepart, number, date), datapart specifies that the part is added, number knows how much to add, date specifies the base on which to add. Datepart values include year, quarter, month, dayofyear, day, week, hour, minute, and second. For example, dateadd (day, 1

); or string format style, to convert float, real, money, or smallmoney data to character data (nchar, nvarchar, char, varchar, nchar, or nvarchar data type ). Output when converted to character data. Implicit conversions are invisible to users.SQL Server automatically converts data from one data type to another. For example, if a smallint variable is compared with an int variable, the smallint variable is implicitly converted to an int variable before the comparison. Explicit conversions use th

SQL function description: Once data is successfully retrieved from a table, you need to further manipulate the data to obtain useful or meaningful results. These requirements include execution of computation and mathematical operations, conversion of data, resolution of numerical values, combination of values and values within the aggregation range. The following table lists the classes and descriptions of

SQL function, described in detail as follows: Avg function Avg function that calculates the arithmetic average of data in a particular field in a query. The syntax is AVG (expression). An expression that can be a field name, a formula, or a function that can be To be an inte

FiddlerFiddler is one of the most powerful Web debugging tools that can record HTTP and HTTPS requests from all clients and servers, allowing you to monitor, set breakpoints, and even modify input and output data. The use of Fiddler is a great help in diagnosing and analyzing problems, both for development and for testing.: Http://www.telerik.com/download/fiddlerOperating principles and instructions for use can be consulted: http://www.cnblogs.com/TankXiao/archive/2012/02/06/2337728.htmlOf cours

top or rowcount keywords. To retrieve a specific subset of evaluations, you need to use a "derived table" (or a view-based approach). Four new evaluation functions were introduced in SQL Server 2005: Row_number,rank,dense_rank and Ntile. Although these are a significant improvement over the functions provided by SQL Server 2000, the use of these functions still has some limitations (requiring the use of d

be implemented by using the top or rowcount keywords. To retrieve a specific subset of evaluations, you need to use a "derived table" (or a view-based approach). Four new evaluation functions were introduced in SQL Server 2005: Row_number,rank,dense_rank and Ntile. Although these are a significant improvement over the functions provided by SQL Server 2000, the use of these functions still has some limitat