大约有 40,000 项符合查询结果(耗时:0.0243秒) [XML]

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Overriding a Rails default_scope

...ed_at desc') end Foo.reorder('created_at asc') runs the following SQL: SELECT * FROM "foos" ORDER BY created_at asc share | improve this answer | follow |...
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SQL query to group by day

...dateadd(DAY,0, datediff(day,0, created)) return '2009-11-02 00:00:00.000' select sum(amount) as total, dateadd(DAY,0, datediff(day,0, created)) as created from sales group by dateadd(DAY,0, datediff(day,0, created)) share ...
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Copy tables from one database to another in SQL Server

... server? Use three part naming. INSERT INTO bar..tblFoobar( *fieldlist* ) SELECT *fieldlist* FROM foo..tblFoobar This just moves the data. If you want to move the table definition (and other attributes such as permissions and indexes), you'll have to do something else. ...
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SQL Joins Vs SQL Subqueries (Performance)?

...e result i was looking for was 739 elements. My query at first was this: SELECT p.id, p.fixedId, p.azienda_id, p.categoria_id, p.linea, p.tipo, p.nome FROM prodotto p WHERE p.azienda_id = 2699 AND p.anno = ( SELECT MAX(p2.anno) FROM prodotto p2 WHERE p2.fixed...
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What is the use of GO in SQL Server Management Studio & Transact SQL?

... gbn make it SELECT and look at what happens :-) – SQLMenace Feb 19 '10 at 21:09 14 ...
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SQL Server - copy stored procedures from one db to another

... Right click on database Tasks Generate Scripts Select the objects you wish to script Script to File Run generated scripts against target database share | improve this an...
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List columns with indexes in PostgreSQL

...constraint uk_test3ab unique (a, b)); List indexes and columns indexed: select t.relname as table_name, i.relname as index_name, a.attname as column_name from pg_class t, pg_class i, pg_index ix, pg_attribute a where t.oid = ix.indrelid and i.oid = ix.indexreli...
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How to group time by hour or by 10 minutes

...time intervals. (There is no collision between years.) Including it in the SELECT statement will give your output a column with pretty output truncated at the level you specify. '2000' is an "anchor date" around which SQL will perform the date math. Jereonh discovered below that you encounter an in...
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python-pandas and databases like mysql

...a_conn = cx_Oracle.connect('your_connection_string') df_ora = pd.read_sql('select * from user_objects', con=ora_conn) print 'loaded dataframe from Oracle. # Records: ', len(df_ora) ora_conn.close() And here is the equivalent example for MySQLdb: import MySQLdb mysql_cn= MySQLdb.connect(host='...
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In SQL, what's the difference between count(column) and count(*)?

...a values(null,1) insert #bla values(1,null) insert #bla values(null,null) select count(*),count(id),count(id2) from #bla results 7 3 2 share | improve this answer | fo...