sql server isnull in where clause

SQL Server performance optimization skills, SQL Server Performance Optimization 1. Select the most efficient table name sequence (only valid in the rule-based Optimizer) The SQL Server parser processes the table names in the FROM

) -- import/export path/file name. If @ tbnameverification indicates that the entire data warehouse is exported, the file name will automatically use table name .txt, @ Isout bit -- 1 is for export, 0 is for ImportAsDeclare @ SQL varchar (8000) If @ tbname like '%. %. %' -- if the table name is specified, a single table is exported directly.BeginSet @ SQL = 'bcp' + @ tbname+ Case when @ isout = 1 then 'out'

WHERE clause.• Isnull -- use isnull for Visual Basic for Applications (VBA ).• Nz -- when a null value is encountered, NZ is used to return values other than null. The above functions are essentially slightly different. Is null and isnull capture null values, while NZ functions process null values. In other words, if

SQL Server SQL statement Import and ExportOverview: SQL statements of the Microsoft SQL Server database are imported and exported, including data imported and exported with other databases and files. /*** Export to excelExec mas

statement may fail, in addition, you receive the 625 error 814893 FIX: error message: "insufficient key column information updates" 2000 FIX in SQL Server 814894 SP3: the stored procedure of xp_readmail only saves the embedded attachments of text. Program (for filtered releases, it may fail. FIX: 814919 FIX: If no message is displayed, the system administrator will log on to the

50 methods to skillfully optimize your SQL Server database There are many reasons for slow query speed. The following are common causes: 1. No index or no index is used (this is the most common problem of slow query and is a defect in programming) 2. Low I/O throughput, resulting in a bottleneck effect. 3. the query is not optimized because no computing column is created. 4. Insufficient memory 5. slow net

name, export all user tables for the database , @filename varchar (1000)--import/Export the path/file name, if the @tbname parameter indicates that the entire database is exported, this parameter is the file store path, the file name automatically with the table name. txt , @isout bit--1 for export, 0 for import As DECLARE @sql varchar (8000) If @tbname like '%.%.% '--If a table name is specified, export a single table directly Begin Set @

Server Database SQL statement Import and Export Daquan, including the import and export of data with other databases and files. /****** Export to excelExec master.. xp_mongoshell 'bcp settledb. DBO. shanghu out c: \ temp1.xls-C-Q-s "gnetdata/gnetdata"-U "sa"-P ""' /*********** Import ExcelSelect *From OpenDataSource ('Microsoft. Jet. oledb.4.0 ','Data source = "C: \ test.xls"; user id = admin; Password =; e

. table Name, all user tables of the database are exported , @ filename varchar (1000) -- import/export path/export , @ isout bit -- 1 is exported, 0: Import as declare @ SQL varchar (8000) If @ tbname like '%. %. % '-- if the table name is specified, export a single table begin set @ SQL = 'bcp' + @ tbname + case when @ isout = 1 then 'out' else 'in' end + '"' + @ filename + '"/W' +'/s' + @ server

) -- import/export path/file name. If @ tbnameverification indicates that the entire data warehouse is exported, the file name will automatically use table name .txt, @ Isout bit -- 1 is for export, 0 is for ImportAsDeclare @ SQL varchar (8000) If @ tbname like '%. %. %' -- if the table name is specified, a single table is exported directly.BeginSet @ SQL = 'bcp' + @ tbname+ Case when @ isout = 1 then 'out'

The first time to see such a SQL statement, do not understand, which used the following less common Aggregate functions: GROUPING Operator used to summarize data: ROLLUP SELECT Case GROUPING (O.customerid) when 0 THEN o.customerid ELSE ' [Total] ' End As Allcustomerssummary, Case GROUPING (Od.orderid) at 0 THEN Od.orderid ELSE-1 end As Individualcustomersummary, SUM (Od.quantity*od.unitprice) as Pri

SQL Server address search performance optimization and SQL server performance optimization This is an example of a long time ago. Now, I have no intention of discovering the materials, so I will take it out and try again. 1. Requirements 1.1 Basic Requirements: Search for the complete address path based on the entered

SQL Server compact does not support top and row_number. the frequently used SQL pages cannot be used in SQL Server compact. How does SQL Server compact implement paging? The answer is o

1. Select the most efficient table name order (valid only in the Rule-based optimizer) The SQL Server parser processes the table names in the FROM clause in Right-to-left order, therefore, the last table in the FROM clause (driving table) is processed first, and in the case where multiple tables are included in the FR

) -- import/export path/file name. If @ tbnameverification indicates that the entire data warehouse is exported, the file name will automatically use table name .txt, @ Isout bit -- 1 is for export, 0 is for ImportAsDeclare @ SQL varchar (8000) If @ tbname like '%. %. %' -- if the table name is specified, a single table is exported directly.BeginSet @ SQL = 'bcp' + @ tbname+ Case when @ isout = 1 then 'out'

enter valid data and then query. •Old table New Add field, need to allow null (avoid full table data Update, long-term lock cause blocking)(This is mainly considering the improvement of the previous table) index design Guidelines• You should create indexes on columns that are used frequently in the WHERE clause • You should create indexes on columns that are frequently used for joining tables • You should create an index on the columns that are used

) FROM MySalesOrderHeader WHERE OrderDate SQL Server optimizes such code much more efficiently than using the set rowcount option. Now, you can stop using the mysalesorderheader table: DROP TABLE MySalesOrderHeaderBack to Top Apply Operator Apply is a new relational operator specified in the from clause of a query. It allows you to call the table value functio

SQL Server implements automatic cyclic archiving of partition data scripts, SQL Server Overview We should all know that in many business scenarios, We need to partition some tables with a large record volume, and archive some old data to ensure performance. In many partition tables, IF manual intervention is required f

Tags: User bar implicit conversion first location assignment set size getWhat is a cursor The result set, which is the collection of all row data returned after the select query. Cursors are a mechanism for working with result sets, which can locate a row in the result set, read or write multiple data, or move the cursor to navigate to the rows you want to manipulate the data. Generally complex stored procedures, there will be the appearance of cursors, his main use is: Navigates to a

to use XML clauses. You 'd better refer to SQL online books. Online Guide SQL Server online books describe the usage of for XML clauses. It also mentions multiple restrictions that must be paid attention to when using this clause. For example, the for XML clause cannot be