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MySQL IF NOT NULL, then display 1, else display 0
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SELECT c.name, IF(a.addressid IS NULL,0,1) AS addressexists
FROM customers c
LEFT JOIN addresses a ON c.customerid = a.customerid
WHERE customerid = 123
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Fastest way to count exact number of rows in a very large table?
I have come across articles that state that SELECT COUNT(*) FROM TABLE_NAME will be slow when the table has lots of rows and lots of columns.
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Inner join vs Where
... for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.id;
SELECT *
FROM TABLE (DBMS_XPLAN.DISPLAY);
-- 0 select statement
-- 1 hash join (access("T1"."ID"="T2"."ID"))
-- 2 table access full table1
-- 3 table access ful...
How to get all options of a select using jQuery?
How can I get all the options of a select through jQuery by passing on its ID?
17 Answers
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What is the difference between precision and scale?
...on. e.g: Precision 4, scale 2 - will fail any number > 99.9999..; try: select cast (99.99999 as NUMBER(4,2)) from dual; //OK; select cast (100.9 as NUMBER(4,2)) from dual; //FAIL;
– Jama Djafarov
Mar 6 '15 at 17:47
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Boolean Field in Oracle
...ate the many Boolean-like
flags that Oracle's data dictionary views use, selecting 'Y' for true
and 'N' for false. However, to interact correctly with host
environments, such as JDBC, OCCI, and other programming environments,
it's better to select 0 for false and 1 for true so it can work
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How to select date without time in SQL
When I select date in SQL it is returned as 2011-02-25 21:17:33.933 . But I need only the Date part, that is 2011-02-25 . How can I do this?
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SQL Group By with an Order By
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In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
share
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Join between tables in two different databases?
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Yes, assuming the account has appropriate permissions you can use:
SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;
You just need to prefix the table reference with the name of the database it resides in.
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Is there a function to deselect all text using JavaScript?
Is there a function in javascript to just deselect all selected text? I figure it's got to be a simple global function like document.body.deselectAll(); or something.
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