how to check blank value in sql server

There is such a requirement that it creates an SQL Server query, including the cumulative value based on the event time. A typical example is a bank account, because every time you save and withdraw money at different times. For any account, you must calculate the sum of the loan (deposit) and loan (withdrawal) at a certain point in time. After each transaction,

; Analysis: Do not use ISNULL to find NULL values. Instead, you should use is NULL. The following example finds all products that have NULL in the weight column. Please note the space between IS and NULL. Copy Code code as follows: Use ADVENTUREWORKS2008R2; Go SELECT Name, Weight From Production.Product WHERE Weight is NULL; Go SQL Server: How to determine wheth

Error behavior: Microsoft OLE DB Provider for SQL Server error ' 80040e2f ' cannot insert value NULL into column ' id ', table ' Web.dbo.dingdan '; column does not allow null values. INSERT failed. /untitled-2.asp, line 115 Reason Analysis: SQL database, the ID column identification specification is not set to Ye

Tags: SQL ServerWhen using SQL Server to import flat File source data, error 0XC02020A1: Error 0xc020902a: Error 0xc02020c5; Error 0xc0047022: Return status value 4 and status text "text is Truncation, or one or more characters that do not have a match in the target code page. Error 0XC02020A1: Data

In SQL Server, if the default value is set for a field in the table, a default constraint is generated in the system table sysobjects.If you want to perform operations on the field with the default value, such as changing the column type and deleting the column, an error is reported. Therefore, before performing operat

: it affects query performance.There are many ways to solve this, and the simplest way is to rebuild the clustered index.CREATE CLUSTERED index Orderid_c on neworders (OrderID) godrop INDEX neworders.orderid_cgoset STATISTICS IO ONSELECT * F ROM NewordersgoWith IO statistics, in addition to analyzing the fragments caused by the forwarded record page above, it is more important to compare the number of reads between different query statements and to optimize the statements by reducing the number

reference to ensure that most of the data is useful, that is, to increase the cache hit rate mentioned above.About this reference value, I analyzed the next, in fact, is divided into two cases of analysis.first , if the data table is a heap table, SQL Server gets it only through full table scan. This way, in order to avoid repeated reads, increase the consumptio

performance. There are many ways to solve the problem, the simplest way is to rebuild the clustered index. CREATE CLUSTERED INDEX Orderid_c on Neworders (OrderID)GoDROP INDEX Neworders.orderid_cGoSET STATISTICS IO onSELECT * from NewordersGo With IO statistics, in addition to analyzing the fragmentation caused by the above page splits, it is more important to use to compare the number of reads between different query statements, and to optimize the statements by reducing the number

Document directory Lifecycle 2.8. DECLARE statement Both SQL server and mysql are our frequently used database systems. Next we will introduce the differences between the values of SQL server and mysql variables, and hope to enlighten you. Variables in SQL

Solution 1:The first idea for this question may be: Is it OK to add a unique key to the caption field? OK, let's follow this thread and create a unique index first.The code is as follows:Create unique nonclustered index UN_TEST_TBOn TEST_TB (caption)Go Index creation Okay, let's test the effect.The code is as follows:Insert into TEST_TB (caption)VALUES (NULL)GoInsert into TEST_TB (caption)VALUES (NULL)Go After running, we receive the following error message:The following are the referenced con

Label:Get through the SQL Server System self-brought function String sql ="INSERT into goods values ('"+ TextBox1.Text +"',"+ TextBox2.Text +", 0,"+ TextBox3.Text +", ', '"+ DropDownList1.SelectedItem.Text +"', '"+ session["username"]. ToString () +"', 0, '"+ Textbox4.text +"' , ' failed '); select Scope_identity ()"; SqlConnection Conn=NewSqlConnection (s); SqlC

Tags: unique prefix primary name sele Post stored Procedure CTS AssociationFirst isolate the default value constraint name for the field, and then delete the default value constraint based on the default value constraint name Declare @constraintName varchar( $) Select @constraintName =B.name fromsyscolumns a,sysobjects bwherea.ID=object_id('Tb_kysubproject') and

Tags: des style blog http io os ar using forSQL Server data full synchronization [Finalize]Copyright, reproduced Please specify the source, thank you! after two days of simultaneous writing and testing, the first release version was made:1. This function only supports one-way synchronization, that is, from a primary database want to multiple from the database synchronization2. Any additions or deletions to the primary database will be synchronized to

When IDENTITY_INSERT is set to OFF, you cannot insert an explicit value into the identity column in table ' #TT '.I was in SQL Server to write the stored procedure encountered this error, then thought: how the temporary table has a primary key, I also did not set the primary key.Then I worked with my colleagues to debug, and finally found out. The reason is that

A few days ago, my colleague asked me how to convert a field value to a column. I wrote a simple Demo to share it. The Code is as follows: -- create a test table and add Test Data createtable # temp (amoney, bvarchar (10) * insertinto # temp (a, B) values () insert A few days ago, a colleague asked me how to convert a field value to a column. I wrote a simple Demo to share it. The Code is as follows: -- cre

------------------ UDF ---------------- Create a user-defined function. This is a stored Transact-SQL or Common Language Runtime (CLR) routine,-- This routine returns a value. User-defined functions cannot be used to modify the database status.-- Like system functions, user-defined functions can be called from queries. Like a stored procedure, scalar functions can be executed using EXECUTE statements. Synta

A few days ago, when I upgraded the database of a Communtiy Server from SQL 2000 to SQL 2005, I encountered a strange problem and reported the following error:Violation of primary key constraint 'pk _ cs_threads'. Cannot insert duplicate key in object 'dbo. cs_threads '.After the analysis, we found that the table's auto-increment field database has reached 6144,

A few days ago, when I upgraded a communtiy Server database from SQL 2000 to SQL 2005, I ran into a weird problem that reported the following error: violation of PRIMARY KEY constraint ' pk_cs_threads '. Cannot insert duplicate key in object ' Dbo.cs_threads '. After the analysis, we found that the table's self-increasing field database has reached 6144, and th

.2, in the table Design window-"Select data Column-" In the Column Properties window to find the default value or binding-"Enter the default value (note The default value of the data type and input format).3. Click the Save button (or Ctrl+s)-"Refresh table-" To open the table again to see the results.Using T-SQL scrip

Both SQL server and mysql are our frequently used database systems. Next we will introduce the differences between the values of SQL server and mysql variables, and hope to enlighten you. Variables in SQL server must be affirmed