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日期:2024-08-06
In Oracle, it's possible to get a count of distinct values in multiple columns by using the || operator (according to this forum post, anyway): SELECT COUNT(DISTINCT ColumnA || ColumnB) FROM MyTable Is there a way to do this in SQL Server 2008? I'm trying...
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日期:2024-08-13
What is it about your existing query that you don't like? If you are concerned that DISTINCT across two columns does not return just the unique permutations why not try it? It certainly works as you might expect in Oracle. SQL> select distinct deptno, job...
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日期:2024-08-09
2 records returned. Count distinct records that contain NULL values The query below is the inner query we just saw which shows a list of distinct values in the ReportsTo column. Note that when we run this query alone, NULL is displayed in the result set, ...
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日期:2024-08-12
Until 11g, Oracle SQL did not have a direct mechanism for allowing multiple values from the same column to be displayed in the same row of output. SQL is designed not to disallow repeating values on a single line of output, but Oracle has several tricks f...
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日期:2024-08-08
As the title suggests I need some help getting a running total in T-SQL. The problem is that the sum I need to do is the sum of a count: sum(count (distinct (customers))) Say if I ......
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日期:2024-08-07
The Database Journal Series index is a listing of articles, which contain more than three installments. It is categorized by database, author name, series title and article title. MS SQL Oracle DB2 MS Access MySQL Michael Aubert Learn SQL Server 2000 ......
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日期:2024-08-08
SQL, MSSQL, MS SQL SQL Server, SQL Server 2000, SQL Server 2005, SQL Server 2008, Microsoft SQL Server ... if you are experiencing performance issues for your queries than it may be due to outdated statistics. An outdated statistic can make the sql server...
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日期:2024-08-10
Index optimization is one of the most important task for every DBA. We need to follow the below mentioned checklist to optimize the Index in very easy manner. Create Index on frequently used columns in T-SQL Code. Columns used in WHERE, ORDER BY and ......