大约有 531 项符合查询结果(耗时:0.0180秒) [XML]

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PHP - add item to beginning of associative array [duplicate]

... You could use the union operator: $arr1 = array('key0' => 'value0') + $arr1; or array_merge. share | improve this answer | ...
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Counting null and non-null values in a single query

...a column... If that is correct: SELECT count(*) FROM us WHERE a IS NULL UNION ALL SELECT count(*) FROM us WHERE a IS NOT NULL Edited to have the full query, after reading the comments :] SELECT COUNT(*), 'null_tally' AS narrative FROM us WHERE a IS NULL UNION SELECT COUNT(*), 'not_null...
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How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?

...source INT) INSERT INTO @TestTable SELECT 1, 10, '2009-03-04', 'john', 399 UNION SELECT 2, 11, '2009-03-04', 'juliet', 244 UNION SELECT 5, 12, '2009-03-04', 'borat', 555 UNION SELECT 3, 10, '2009-03-03', 'john', 300 UNION SELECT 4, 11, '2009-03-03', 'juliet', 200 UNION SELECT 6, 12, '2009-03-03', 'b...
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Is having an 'OR' in an INNER JOIN condition a bad idea?

...LECT * FROM maintable m JOIN othertable o ON o.parentId = m.id UNION SELECT * FROM maintable m JOIN othertable o ON o.id = m.parentId , each of them being an equijoin, however, SQL Server's optimizer is not smart enough to see it in the query you wrote (though they are logi...
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+ operator for array in PHP?

...and array) ) So the logic of + is equivalent to the following snippet: $union = $array1; foreach ($array2 as $key => $value) { if (false === array_key_exists($key, $union)) { $union[$key] = $value; } } If you are interested in the details of the C-level implementation head t...
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Return a value if no rows are found in Microsoft tSQL

...ight be a dead horse, another way to return 1 row when no rows exist is to UNION another query and display results when non exist in the table. SELECT S.Status, COUNT(s.id) AS StatusCount FROM Sites S WHERE S.Id = @SiteId GROUP BY s.Status UNION ALL --UNION BACK ON TABLE WITH NOT EXISTS SELECT 'N/...
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SQL query return data from multiple tables

... Part 1 - Joins and Unions This answer covers: Part 1 Joining two or more tables using an inner join (See the wikipedia entry for additional info) How to use a union query Left and Right Outer Joins (this stackOverflow answer is excellent t...
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How to use Git properly with Xcode?

...add this line to a .gitattributes file: *.pbxproj text -crlf -diff -merge=union Then git will always take both sides of a merge for the .pbxproject files, having the same effect as the script I provided only without any extra work. Lastly, here is my complete .gitignore file, showing what I do h...
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SQL Logic Operator Precedence: And and Or

... expression truth table : ;WITH cteData AS (SELECT 0 AS A, 0 AS B, 0 AS C UNION ALL SELECT 0,0,1 UNION ALL SELECT 0,1,0 UNION ALL SELECT 0,1,1 UNION ALL SELECT 1,0,0 UNION ALL SELECT 1,0,1 UNION ALL SELECT 1,1,0 UNION ALL SELECT 1,1,1 ) SELECT cteData.*, CASE WHEN (A=1) OR (B=1) AND (C=1) ...
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Is gcc's __attribute__((packed)) / #pragma pack unsafe?

...option, enabled by default. When address of packed member of struct or union is taken, it may result in an unaligned pointer value. This patch adds -Waddress-of-packed-member to check alignment at pointer assignment and warn unaligned address as well as unaligned pointer I've just built t...