大约有 41,000 项符合查询结果(耗时:0.0291秒) [XML]

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Entity Framework select distinct name

... Using lambda expression.. var result = EFContext.TestAddresses.Select(m => m.Name).Distinct(); share | improve this answer | follow | ...
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How do I select an entire row which has the largest ID in the table?

... You could use a subselect: SELECT row FROM table WHERE id=( SELECT max(id) FROM table ) Note that if the value of max(id) is not unique, multiple rows are returned. If you only want one such row, use @MichaelMior's answer, SELEC...
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Is there a way to make text unselectable on an HTML page? [duplicate]

...an HTML UI with some text elements, such as tab names, which look bad when selected. Unfortunately, it's very easy for a user to double-click a tab name, which selects it by default in many browsers. ...
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Is there a combination of “LIKE” and “IN” in SQL?

... An example table: SQL> create table mytable (something) 2 as 3 select 'blabla' from dual union all 4 select 'notbla' from dual union all 5 select 'ofooof' from dual union all 6 select 'ofofof' from dual union all 7 select 'batzzz' from dual 8 / Table created. The origin...
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How do you use the “WITH” clause in MySQL?

...s mentioned, you provided a poor example - there's no need to perform a subselect if you aren't altering the output of the columns in any way: SELECT * FROM ARTICLE t JOIN USERINFO ui ON ui.user_userid = t.article_ownerid JOIN CATEGORY c ON c.catid = t.article_categoryid WHERE t....
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NOT IN vs NOT EXISTS

...llow NULLs the NOT IN will be treated identically to the following query. SELECT ProductID, ProductName FROM Products p WHERE NOT EXISTS (SELECT * FROM [Order Details] od WHERE p.ProductId = od.ProductId) The exact plan may vary but for my examp...
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Fastest check if row exists in PostgreSQL

... Use the EXISTS key word for TRUE / FALSE return: select exists(select 1 from contact where id=12) share | improve this answer | follow ...
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SQL Server SELECT LAST N Rows

...d database... Now let us retrieve the Last 5 orders placed by Employee 5: SELECT ORDERID, CUSTOMERID, OrderDate FROM ( SELECT ROW_NUMBER() OVER (PARTITION BY EmployeeID ORDER BY OrderDate DESC) AS OrderedDate,* FROM Orders ) as ordlist WHERE ordlist.EmployeeID = 5 AND ordlist.OrderedDate &...
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how to exclude null values in array_agg like in string_agg using postgres?

... SQL Fiddle select id, (select array_agg(a) from unnest(canonical_users) a where a is not null) canonical_users, (select array_agg(a) from unnest(non_canonical_users) a where a is not null) non_canonical_users from ( SELE...
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Rails select helper - Default selected value, how?

... This should do it: <%= f.select :project_id, @project_select, :selected => params[:pid] %> share | improve this answer | ...