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PostgreSQL function for last inserted ID
...e:
INSERT INTO persons (lastname,firstname) VALUES ('Smith', 'John');
SELECT currval('persons_id_seq');
The name of the sequence must be known, it's really arbitrary; in this example we assume that the table persons has an id column created with the SERIAL pseudo-type. To avoid relying on thi...
How to import a jar in Eclipse
...o this folder all the jar files you need.
Refresh your project in eclipse.
Select all the jar files, then right click on one of them and select Build Path -> Add to Build Path
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MySQL Query GROUP BY day / month / year
... for added clarity in some cases such as where records span several years. SELECT COUNT(event_id), DATE_FORMAT(event_start, '%Y/%m')
– Ric
Apr 4 '13 at 10:25
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Datetime equal or greater than today in MySQL
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SELECT * FROM users WHERE created >= CURDATE();
But I think you mean created < today
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Changing the selected option of an HTML Select element
In my HTML, I have a <select> with three <option> elements. I want to use jQuery to check each option's value against a Javascript var . If one matches, I want to set the selected attribute of that option. How would I do that?
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How does MySQL process ORDER BY and LIMIT in a query?
...e LIMIT clause can be used to constrain the number of rows returned by the SELECT statement. LIMIT takes one or two numeric arguments, which must both be nonnegative integer constants (except when using prepared statements).
With two arguments, the first argument specifies the offset of the first ...
How can you determine how much disk space a particular MySQL table is taking up?
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For a table mydb.mytable run this for:
BYTES
SELECT (data_length+index_length) tablesize
FROM information_schema.tables
WHERE table_schema='mydb' and table_name='mytable';
KILOBYTES
SELECT (data_length+index_length)/power(1024,1) tablesize_kb
FROM information_schema....
How can I select random files from a directory in bash?
I have a directory with about 2000 files. How can I select a random sample of N files through using either a bash script or a list of piped commands?
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How do I cast a string to integer and have 0 in case of error in the cast with PostgreSQL?
...dn't want the overhead of a function. I came up with the following query:
SELECT myfield::integer FROM mytable WHERE myfield ~ E'^\\d+$';
Postgres shortcuts its conditionals, so you shouldn't get any non-integers hitting your ::integer cast. It also handles NULL values (they won't match the regex...
Referring to a Column Alias in a WHERE Clause
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SELECT
logcount, logUserID, maxlogtm,
DATEDIFF(day, maxlogtm, GETDATE()) AS daysdiff
FROM statslogsummary
WHERE ( DATEDIFF(day, maxlogtm, GETDATE() > 120)
Normally you can't refer to field aliases in the WHERE clau...