大约有 40,000 项符合查询结果(耗时:0.0247秒) [XML]

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Get top n records for each group of grouped results

...ould need to specify the group number and add queries for each group: ( select * from mytable where `group` = 1 order by age desc LIMIT 2 ) UNION ALL ( select * from mytable where `group` = 2 order by age desc LIMIT 2 ) There are a variety of ways to do this, see this articl...
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Javascript fuzzy search that makes sense

... pairs1 = get_bigrams(str1) pairs2 = get_bigrams(str2) union = pairs1.length + pairs2.length hit_count = 0 for x in pairs1 for y in pairs2 if x is y hit_count++ if hit_count > 0 return ((2.0 * ...
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Cannot resolve the collation conflict between “SQL_Latin1_General_CP1_CI_AS” and “Latin1_General_CI_

...eck what collations each column in your table(s) has by using this query: SELECT col.name, col.collation_name FROM sys.columns col WHERE object_id = OBJECT_ID('YourTableName') Collations are needed and used when ordering and comparing strings. It's generally a good idea to have a sin...
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Elegant way to combine multiple collections of elements?

...in a collection (e.g., of type List<List<int>> , I could use SelectMany to combine them all into one collection. ...
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Intersection and union of ArrayLists in Java

... Test().intersection(list1, list2)); System.out.println(new Test().union(list1, list2)); } public <T> List<T> union(List<T> list1, List<T> list2) { Set<T> set = new HashSet<T>(); set.addAll(list1); set.addAll(list2); ...
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What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN? [duplicate]

...These pictures don't do it for me. Why is the top right picture not simply SELECT * FROM TableA;? Why is the top left picture not simply SELECT * FROM TableB;? Why is the top middle picture not SELECT * FROM A INTERSECT SELECT * FROM B ? etc – onedaywhen Sep 9 ...
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Is there a Max function in SQL Server that takes two values like Math.Max in .NET?

... return isnull(@val2,@val1) end ... and you would call it like so ... SELECT o.OrderId, dbo.InlineMax(o.NegotiatedPrice, o.SuggestedPrice) FROM Order o share | improve this answer | ...
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Optimal way to concatenate/aggregate strings

...Transact SQL, which should work fine in Azure. ;WITH Partitioned AS ( SELECT ID, Name, ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Name) AS NameNumber, COUNT(*) OVER (PARTITION BY ID) AS NameCount FROM dbo.SourceTable ), Concatenated AS ( SELECT ...
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How to output MySQL query results in CSV format?

...ech-recipes.com/rx/1475/save-mysql-query-results-into-a-text-or-csv-file/ SELECT order_id,product_name,qty FROM orders WHERE foo = 'bar' INTO OUTFILE '/var/lib/mysql-files/orders.csv' FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\n'; Using this command columns names will not be e...
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MySQL, Check if a column exists in a table with SQL

...query and I think it needs a small alteration to get it working properly. SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'table_name' AND COLUMN_NAME = 'column_name' That worked for me. Thanks! ...