大约有 44,000 项符合查询结果(耗时:0.0270秒) [XML]

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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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Get the Highlighted/Selected text

... Getting the text the user has selected is relatively simple. There's no benefit to be gained by involving jQuery since you need nothing other than the window and document objects. function getSelectionText() { var text = ""; if (window.getSelecti...
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Insert into … values ( SELECT … FROM … )

... Try: INSERT INTO table1 ( column1 ) SELECT col1 FROM table2 This is standard ANSI SQL and should work on any DBMS It definitely works for: Oracle MS SQL Server MySQL Postgres SQLite v3 Teradata DB2 Sybase Vertica HSQLDB H2 AWS RedShift SA...
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Insert Data Into Temp Table with Query

... SELECT * INTO #Temp FROM (SELECT Received, Total, Answer, (CASE WHEN application LIKE '%STUFF%' THEN 'MORESTUFF' END) AS application FROM FirstTable WHERE Recieved = 1 AND applicati...
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MySQL LIKE IN()?

... might be more efficient, but you'd have to benchmark it to be sure, e.g. SELECT * from fiberbox where field REGEXP '1740|1938|1940'; share | improve this answer | follow ...
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Select statement to find duplicates on certain fields

...get the list of fields for which there are multiple records, you can use.. select field1,field2,field3, count(*) from table_name group by field1,field2,field3 having count(*) > 1 Check this link for more information on how to delete the rows. http://support.microsoft.com/kb/139444 There sh...
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Opening a folder in explorer and selecting a file

I'm trying to open a folder in explorer with a file selected. 11 Answers 11 ...
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How to select all records from one table that do not exist in another table?

... SELECT t1.name FROM table1 t1 LEFT JOIN table2 t2 ON t2.name = t1.name WHERE t2.name IS NULL Q: What is happening here? A: Conceptually, we select all rows from table1 and for each row we attempt to find a row in table2 wi...
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MySQL ON vs USING?

...n tables ON a column, a set of columns and even a condition. For example: SELECT * FROM world.City JOIN world.Country ON (City.CountryCode = Country.Code) WHERE ... USING is useful when both tables share a column of the exact same name on which they join. In this case, one may say: SELECT ... FR...
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How do I do top 1 in Oracle?

... If you want just a first selected row, you can: select fname from MyTbl where rownum = 1 You can also use analytic functions to order and take the top x: select max(fname) over (rank() order by some_factor) from MyTbl ...