SQL子查询 sql SQLServer SQL子查询
SQL子查询。一、非关联子查询 （一）子查询 就是在一条SQL语句中嵌入另一条SQL语句select sal from empwhere ename='FORD';select sal from empwhere sal>300;select ename from empwhere sal>(select sal from emp where...
View ArticleSQL建表及插入 sql SQLServer SQL建表 SQL插入
SQL建表及插入。一、建表（一）creat语句的基本用法create table[schema] table(column datatype [default expr] [column_constraint],...[table_constraint]);例子：creat table student(id NUMBER PRIMARY KEY,name VARCHAR(20),email...
View Article解决PL/SQLDeveloper连接数据库时出现“ORA-12541:TNS:无监听程序”错误。 sql SQLSer ...
解决PL/SQLDeveloper连接数据库时出现“ORA-12541:TNS:无监听程序”错误。在用PL/SQL Developer连接数据库时出现“ORA-12541:TNS:无监听程序”错误。1、检查listener.log日志发现下面错误：TNSLSNR for 32-bit windows: Version 10.2.0.1.0 - Production on 20-9月 -2008...
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SQLSERVER――索引的重要性 sql SQLServer 数据库索引
SQLSERVER——索引的重要性。我想刚刚开始学数据库的在校学生都知道索引对语句性能的重要性。但他们可能不知道，对语句的重要性就是对系统的重要性! 开篇小测验 下面这样一个小SQL 你该怎么样添加最优索引 两个表上现在只有聚集索引 bigproduct 表上已经有聚集索引 ProductID bigtransactionhistory 表上已经有聚集索引 TransactionID select...
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How Much do SQL Server Data Professionals Make?
You’ve thought about your career, you can’t make up your mind about which direction you want to take it. You want to make an informed decision and work out if the career you chose will provide you...
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Overview of Columnstore Indexes in SQL Server
As Aaron Bertrand has written about recently , SQL Server 2016 SP1 opens up a lot of new possibilities for Standard, Web, and Express editions of SQL Server, including new options for in-memory...
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The Last SSIS Book You Read
Every now and then I get an email or meet someone at an event and they say something like, “I learned SSIS from your book!” I’m not going to lie to you, that makes me feel pretty good. Since I’ve...
View ArticleImplementing Fuzzy Sets in SQL Server, Part 8: Possibility Theory and Alpha Cuts
By Steve Bolton ………… To get the point across that fuzzy sets require membership grades of some sort, throughout this series I’ve borrowed the stored procedure I coded for Outlier Detection with SQL...
View ArticleUsing the Chronometer PowerShell module to analyse module performance
Whilst going through my blog roll on Feedly this weekend, I spotted Kevin Marquette’s blog post announcing his new Chronometer module. At a high level it generates a script profiler timeline as you...
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SQL SERVER FIX Error 1402. Could not open key: UNKNOWN\Components. System ...
While installing Service Pack 3 for SQL Server, I was welcomed by a strangeerror about UNKNOWN\Components. Line 2421: MSI (s) (C8:98) [22:31:05:835]: Product: Microsoft SQL Server System CLR Types...
View ArticleTechniques to handle timing issues and inconsistent data for SQL Server data...
By:Tim Smith || Related Tips:More >Import and Export Problem We have several APIs where we extract data and the sources are not always consistent in timing and data. Sometimes an API that we...
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Search for Multiple File Extenstions with the SSIS Foreach File Enumerator
By:Nat Sundar || Related Tips:More > Integration Services Control Flow Transformations Problem I have a requirement to search for multiple file extensions in a folder. However, in SQL Server...
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New Solutions for Old Problems T-SQL Tuesday #87
This is an interesting T-SQL Tuesday this month. For #87, we have an invitation from Matt Gordon. The topic is using new tools to solve old problems. The “new” cutoff is SQL Server 2014, so we’d...
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Solving the Net Changes Problem with Temporal Tables (T-SQL Tuesday #087)
SQL Server 2008 was perhaps not the meatiest of SQL Server releases, but it did have one especially promising feature: Data change detection. Or maybe two features, depending on how you look at things....
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T-SQL Tuesday #87 : Shiny New Toys
This month's T-SQL Tuesday hosted by Matt Gordon ( @sqlatspeed ) is called "Fixing Old Problems with Shiny New Toys." Matt wants us to write about how we've solved old problems in new ways afforded by...
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Calculated Tables and Role-Playing Dimensions
Working with role playing dimensions, which are found when you have say multiple dates in a table and you want to relate them back to a single date table, have always been problematic in SQL Server...
View Articlesql之leftjoin、rightjoin、innerjoin的区别 数据库 数据库学习 sql语句 rightjoin
sql之leftjoin、rightjoin、innerjoin的区别。 left join(左联接) 返回包括左表中的所有记录和右表中联结字段相等的记录。 right join(右联接) 返回包括右表中的所有记录和左表中联结字段相等的记录。 inner join(等值连接) 只返回两个表中联结字段相等的行。 举例如下：...
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Scaling out SSRS on SQL Server Standard Edition
I have been working with SSRS since its initial release in 2004 and have written about it extensively over the years, mostly favorably. Despite its myriad shortcomings, obtuse errors and required hacks...
View ArticleT-SQL Tuesday #87 Fixing Old Problems with Shiny New Toys
Matt Gordon ( b | l | t ) is hosting this months TSQL2SDAY which is on the topic fixing an old issue/problem with shiny new toys. I am really happy about this topic, as it offers the opportunity to...
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Galaxy classification with deep learning and SQL Server R Services
One of the major "wow!" moments in the keynote where SQL Server 2016 was first introduced was a demo that automated the process classifying images of galaxies in a huge database of astronomical...
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