tsql nullif

the use of Isnull,ifnull,nullif is as follows: use of IsNull (expr):If expr is null, then the return value of IsNull () is 1, otherwise the return value is 0.Mysql> Select IsNull (1+1);-> 0Mysql> Select IsNull (1/0);-> 1It is usually wrong to use the null value of =. The IsNull () function has some of the same attributes as the IS null comparison operator. See description for IS null. use of Ifnull (EXPR1,EXPR2): If EXPR1 is not null, then the return

SELECT ifnull (1, ' Test ') as test;In this example, the type of the test column is CHAR (4).Nullif (EXPR1,EXPR2)If EXPR1=EXPR2 is true, the return value is NULL, otherwise the return value is EXPR1. This andCase if EXPR1=EXPR2 then NULLELSEExpr1End is the same.Mysql>select Nullif (a);->nullMysql>select Nullif ();->1If the arguments are not equal, the MySQL two-

Today used in the MySQL IsNull only found him and MSSQL in a little difference, now briefly summarize: The usage of isnull,ifnull,nullif in MySQL is as follows: Usage of IsNull (expr):If expr is null, then the return value of IsNull () is 1, otherwise the return value is 0.Mysql> Select IsNull (+);0Mysql> Select IsNull (1/0);1The comparison of NULL values using = is usually wrong.The IsNull () function has some of the same characteristics as the IS nu

The usage of isnull,ifnull,nullif in MySQL is as follows:Usage of IsNull (expr):If expr is null, then the return value of IsNull () is 1, otherwise the return value is 0.Mysql> Select IsNull (+);0Mysql> Select IsNull (1/0);1The comparison of NULL values using = is usually wrong.The IsNull () function has some of the same characteristics as the IS null comparison operator. See the description for is null.Usage of ifnull (EXPR1,EXPR2): If expr1 is not

1. View the information for the tableIn the TSQL editor, select a table,Click Alt+f1 to view the table's attribute definitions2, use ALT to BULK INSERT commasUsing the IN clause in the TSQL, in the (value_list) list, there are often many numbers, how to quickly add commas, you can use the ALTThe TSQL code is as follows, place the mouse in front of 19, click Alt,

Ifnull (EXPR1,EXPR2) If EXPR1 is not NULL, then the return value of Ifnull () is expr1; Otherwise, its return value is EXPR2. The return value of Ifnull () is either a number or a string, depending on the context in which it is used. Mysql> SELECT ifnull (1,0); -> 1 Mysql> SELECT ifnull (null,10); -> 10 Mysql> SELECT ifnull (1/0,10); -> 10 Mysql> SELECT ifnull (1/0, ' yes '); -> ' yes ' The default result value for Ifnull (EXPR1,EXPR2) is one of the more "generic" in two expressions, i

Source: http://blog.csdn.net/a466350665/article/details/52994761http://blog.csdn.net/xingyu0806/article/details/52080962ifnull (EXPR1,EXPR2) usage: if EXPR1 is not NULL, the return value of Ifnull () is expr1; Otherwise its return value is EXPR2. The return value of Ifnull () is either a number or a string, depending on the context in which it is used. mysql> SELECT ifnull (1,0); nbsp 1 mysql> SELECT ifnull (null,10); NBSP;NBSP N Bsp NBSP;NBSP mys

Tags: create results Runtime book ETL mode assignment SQL dataTypically, an ETL engineer creates an agent job to periodically execute a stored procedure that package,agent the underlying call SSISDB (catalog.start_execution) to initiate an execution instance in synchronous mode, which means that We can simulate the behavior of the agent job and execute the package using the TSQL script. Each time the SSIS engine executes the package, an execution inst

System.drawing.size-argumentlist 80, 15$label 2. Text = "User name:"$textbox 2=new-object System.Windows.Forms.TextBox$textBox 2.Multiline = $true;$textBox 2.Text = ""$textBox 2.Size = New-object system.drawing.size-argumentlist 150, 15$textBox 2.Location = New-object system.drawing.point-argumentlist 90, 50#获取第三个参数$label 3 = New-object System.Windows.Forms.Label;$label 3. Location = New-object System.drawing.point-argumentlist 1, 90$label 3. Size = New-object System.drawing.size-argumentlist 8

1, demand analysisImplement hierarchies in TSQL, such as a data structure, province, city, County, township, village, how to use a table to represent this data structure, and allow is asymmetric, for example, Shanghai is a municipality, there is no province.Create Table dbo.hierarchy (ID intnotnullprimarykey, --type int not NULL,intnotnullvarchar( - not NULL )The type represents the types, which can be set: Province, type is 1, city, type is 2, an

Label:Using execute and sp_executesql to implement dynamic TSQL, how to get the return value of dynamic TSQL? Part I.: Execute 1,execute is a function that executes an SQL statement, and the example statement is as follows Declare @sql nvarchar(Max) Declare @return_cnt int if object_id('tempdb: #tempcnt') is not NULL Drop Table#tempcnt Create Table#tempcnt (CNTint) Set @sql=N'INSERT INTO #tempcnt select

Tags: oracle null value judgment function1. Nvl functionNVL (EXPR1,EXPR2), returns EXPR2 if Expr1 is empty;2. NVL2 functionNVL2 (EXPR1,EXPR2,EXPR3), returns EXPR3 if Expr1 is empty, otherwise returns EXPR2;3. Nullif functionNullif (EXPR1,EXPR2), if EXPR1=EXPR2, returns NULL, otherwise returns EXPR1, requiring two expression data types to be consistent;sql> INSERT INTO T1 values (9);Note that the 1:NVL and NVL2 functions perform the expression in the f

Label:Original Ode-tsql convert Query to JSONTsql-query to JSONIt is my philosophy, good development starts with the data. I have all stressed whenever possible allow your data processing to take place on your SQL Server or database Processin G engine and rendering of the data to the application control engine. By the time your application server receives the data it should is in the truncated, filtered, limited by rows, converted To correct formats,

Label:Lead and Lag are two analytic functions in TSQL, and the order of execution is used to move forward and back the result set of a query after the SELECT statement. If the window function does not partition the result set of the query, the entire result set is treated as a partition, and if the window function partitions The result set of the query, then the lead and lag are the forward and post-move operations on the partition. A window is define

Some TSQL statements with statistical functions (such as DBCC statements, global functions, and system stored procedures) can also help you understand and monitor SQL server running status DBCC statements, the DBCC statement is the Database Console Command of SQL2005. the DBCC statement can not only check the performance and activity of the database, but also check the physical and logical consistency of the database. Some

How to know how long the TSQL statement has been runningDeclare @ms_per_tick decimal(Ten,6)--millisecond per tickSELECT @ms_per_tick=1.0*DateDiff(Millisecond,sqlserver_start_time,getdate())/(ms_ticks-sqlserver_start_time_ms_ticks) fromSys.[Dm_os_sys_info];--SELECT @ms_per_tickSelectReq.session_id,req.start_time Request_start_time, ((SelectMs_ticks fromsys.dm_os_sys_info)-Workers.task_bound_ms_ticks)*@ms_per_tick 'Ms_since_task_bound',DATEDIFF(Ms,re

ISNULL in SQL Server differs from ISNULL in ASP, with two parameters in SQL Server, syntax:ISNULL (Check_expression, Replacement_value) check_expression and Replacement_value data types must be consistent• If Check_expression is NULL, return Replacement_value• If check_expression is not NULL, return check_expression Nullif is used to check two expressions, syntax:Nullif (expression, expression)• If two expression are equal, NULL is returned, which i

Some of the functions recently used in MySQL, some of which are also first encountered, are recorded as follows:1. IsNull (expr)usage: expr is null, then the return value of IsNull () is 1, otherwise the return value is 0.2. Ifnull (EXPR1,EXPR2)Usage: If EXPR1 is not NULL, the return value of Ifnull () is expr1; Otherwise its return value is EXPR2.3.nullif (EXPR1,EXPR2)Usage: if Expr1 =EXPR2 is established, the return value is NULL, otherwise the retu

The syntax of plsql is different from that of tsql. For more information, see. The syntax of plsql is different from that of tsql. For more information, see. Insert into testtable (recordnumber, currentdate) values (I, sysdate ); Print ''; Select @ I = @ I + 1; End; After comparison, we can see that it is different. The command structure in plsql is Delacre Define statement segments Begin Execution state

Tags: logs convert weight made with int span app DivSQL Server Profiler caught a lot of code in the job, applicationname similar to Sqlagent-tsql JobStep (Job 0x94b9b5c016e8d94fb50898c868314d08:st EP 1) Such a Need to convert the binary name in the job into job_id The conversion is done in the following ways: Declare @JobID uniqueidentifier SELECT @JobID = 0x94b9b5c016e8d94fb50898c868314d08 PRINT 'My JobID is' + Convert(Char(255),@JobID) Select *