大约有 47,000 项符合查询结果(耗时:0.0494秒) [XML]

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Eclipse: Can you format code on save?

...ces, choose Java --> Editor --> Save Actions. Check the Perform the selected actions on save, and check the Format source code box. This may or may not be available in previous versions of Eclipse. I know it works in: Version: 3.3.3.r33x_r20080129-_19UEl7Ezk_gXF1kouft<br> Build id: M...
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SQL Server 2008: how do I grant privileges to a username?

...' If you need to be more granular, you can use the GRANT command: GRANT SELECT, INSERT, UPDATE ON dbo.YourTable TO YourUserName GRANT SELECT, INSERT ON dbo.YourTable2 TO YourUserName GRANT SELECT, DELETE ON dbo.YourTable3 TO YourUserName and so forth - you can granularly give SELECT, INSERT, UP...
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Does the join order matter in SQL?

...t matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*. For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much more complicated. First, outer joins are not commutative, so a LEFT JOIN b is no...
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How do MySQL indexes work?

...be faster to go through the pages one by one (in a database, this is "poor selectivity"). For a 10-page book, it makes no sense to make an index, as you may end up with a 10-page book prefixed by a 5-page index, which is just silly - just scan the 10 pages and be done with it. The index also needs t...
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Is there a JSON equivalent of XQuery/XPath?

...g tools including filtering, recursive search, sorting, mapping, range selection, and flexible expressions with wildcard string comparisons and various operators. JSONselect has another point of view on the question (CSS selector-like, rather than XPath) and has a JavaScript implementation. ...
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Transaction isolation levels relation with locks on table

... writes data and commit/rollback (depending on results). B just executes a SELECT statement to read data. C reads and updates data. All these process work on the same table T. READ UNCOMMITTED - no lock on the table. You can read data in the table while writing on it. This means A writes data (unc...
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SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column

...result set to update is before running the update (same query, just with a select): select * from QuestionTrackings q inner join QuestionAnswers a on q.AnswerID = a.AnswerID where q.QuestionID is null -- and other conditions you might want Particularly whether each answer id has definitely only 1...
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How to automatically generate getters and setters in Android Studio

...ar -> Code -> Generate... and then using shift or control button, select all the variables you need to add getters and setters share | improve this answer | follow ...
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Is there a MySQL option/feature to track history of changes to records?

...i AFTER INSERT ON MyDB.data FOR EACH ROW INSERT INTO MyDB.data_history SELECT 'insert', NULL, NOW(), d.* FROM MyDB.data AS d WHERE d.primary_key_column = NEW.primary_key_column; CREATE TRIGGER MyDB.data__au AFTER UPDATE ON MyDB.data FOR EACH ROW INSERT INTO MyDB.data_history SELECT 'up...
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Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法 - 数据库(内核) - 清...

Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法select * from ( select * from tablexxx order by xxx desc ) where rownum <= Noracle数据库不支持mysql中limit, top功...select * from ( select * from tablexxx order by xxx desc ) where rownum <= N oracle数据库不支持mysql中li...