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How to declare variable and use it in the same Oracle SQL script?

...; exec :name := 'SALES' PL/SQL procedure successfully completed. SQL> select * from dept 2 where dname = :name 3 / DEPTNO DNAME LOC ---------- -------------- ------------- 30 SALES CHICAGO SQL> A VAR is particularly useful when we want to call a stored...
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MySQL - Get row number on select

Can I run a select statement and get the row number if the items are sorted? 5 Answers ...
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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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You can't specify target table for update in FROM clause

...llow you to write queries like this: UPDATE myTable SET myTable.A = ( SELECT B FROM myTable INNER JOIN ... ) That is, if you're doing an UPDATE/INSERT/DELETE on a table, you can't reference that table in an inner query (you can however reference a field from that outer table...) Th...
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What is the best way to detect a mobile device?

... @Andrew but from a developer perspective, those devices must be such a tiny percentage of mobile users that they're not worth catering to. Especially in the U.S. – Telarian Feb 7 '19 at 15:00 ...
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Simple way to transpose columns and rows in SQL?

...3, 5), ('Blue', 2, 2, 9, 1); Union All, Aggregate and CASE Version: select name, sum(case when color = 'Red' then value else 0 end) Red, sum(case when color = 'Green' then value else 0 end) Green, sum(case when color = 'Blue' then value else 0 end) Blue from ( select color, Paul value...
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How do I limit the number of rows returned by an Oracle query after ordering?

...Oracle in this answer). To answer the original question, here's the query: SELECT * FROM sometable ORDER BY name OFFSET 20 ROWS FETCH NEXT 10 ROWS ONLY; (For earlier Oracle versions, please refer to other answers in this question) Examples: Following examples were quoted from linked page, in th...
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How do I expire a PHP session after 30 minutes?

.../ Taking now logged in time. // Ending a session in 30 minutes from the starting time. $_SESSION['expire'] = $_SESSION['start'] + (30 * 60); header('Location: http://localhost/somefolder/homepage.php'); } else { echo "Please enter the username ...
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SQL WHERE.. IN clause multiple columns

...a derived table from the subquery, and join table1 to this derived table: select * from table1 LEFT JOIN ( Select CM_PLAN_ID, Individual_ID From CRM_VCM_CURRENT_LEAD_STATUS Where Lead_Key = :_Lead_Key ) table2 ON table1.CM_PLAN_ID=table2.CM_PLAN_ID AND table1.Individual=table2.Indi...
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When should we use mutex and when should we use semaphore

... must happen in the same thread later on. e.g.: If you are deleting a node from a global linked list, you do not want another thread to muck around with pointers while you are deleting the node. When you acquire a mutex and are busy deleting a node, if another thread tries to acquire the same mutex,...