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LISTAGG in Oracle to return distinct values

...ta as ( select 'A' as col1, 'T_a1' as col2, '123' as col3 from dual union select 'A', 'T_a1', '456' from dual union select 'A', 'T_a1', '789' from dual union select 'A', 'T_a2', '123' from dual union select 'A', 'T_a2', '456' from dual union select 'A', 'T_a2', '111' from dual union select 'A...
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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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Is it possible to specify condition in Count()?

... [varchar](50) NOT NULL) INSERT INTO @tbl (id, field) SELECT 1, 'Manager' UNION SELECT 2, 'Manager' UNION SELECT 3, 'Customer' UNION SELECT 4, 'Boss' UNION SELECT 5, 'Intern' UNION SELECT 6, 'Customer' UNION SELECT 7, 'Customer' UNION SELECT 8, 'Wife' UNION SELECT 9, 'Son' SELECT * FROM @tbl SELE...
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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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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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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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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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+ 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...