大约有 44,000 项符合查询结果(耗时:0.0482秒) [XML]

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Select n random rows from SQL Server table

I've got a SQL Server table with about 50,000 rows in it. I want to select about 5,000 of those rows at random. I've thought of a complicated way, creating a temp table with a "random number" column, copying my table into that, looping through the temp table and updating each row with RAND() , and ...
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Hidden Features of SQL Server

...xing table ?''', @Command2 = 'dbcc dbreindex(''?'')', @Command3 = 'select count (*) [?] from ?' Also, sp_MSforeachdb share edited Feb 17 '10 at 2:34 ...
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Caveats of select/poll vs. epoll reactors in Twisted

...o based apps ) leads me to believe that ePoll is a natural replacement for Select and Poll based networking, especially with Twisted. Which makes me paranoid, its pretty rare for a better technique or methodology not to come with a price. ...
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ElasticSearch, Sphinx, Lucene, Solr, Xapian. Which fits for which usage? [closed]

... SET NAMES utf8 # query before fetching rows to index sql_query = SELECT *, id AS pid, CRC32(safetag) as safetag_crc32 FROM hb_posts sql_attr_uint = pid # pid (as 'sql_attr_uint') is necessary for sphinx # this field must be unique # that is why I like sphinx # you ...
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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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Show MySQL host via SQL Command

... To get current host name :- select @@hostname; show variables where Variable_name like '%host%'; To get hosts for all incoming requests :- select host from information_schema.processlist; Based on your last comment, I don't think you can resolve IP...
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How to show SQL queries run in the Rails console?

...ecord::Relation’s to_sql method: User.where(:id => 3).to_sql #=> "SELECT \"users\".* FROM \"users\" WHERE \"users\".\"id\" = 3" share | improve this answer | follo...
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Regular expression to limit number of characters to 10

...a regular expression that will only allow lowercase letters and up to 10 characters. What I have so far looks like this: ...
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List all tables in postgresql information_schema

... You should be able to just run select * from information_schema.tables to get a listing of every table being managed by Postgres for a particular database. You can also add a where table_schema = 'information_schema' to see just the tables in the informat...
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ActiveRecord OR query

...here(t[:author].eq("Someone").or(t[:title].matches("%something%"))).to_sql SELECT "posts".* FROM "posts" WHERE (("posts"."author" = 'Someone' OR "posts"."title" LIKE '%something%')) share | ...