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Convert a Scala list to a tuple?
... hence known at compile time. For example, (1,'a',true) has the type (Int, Char, Boolean), which is sugar for Tuple3[Int, Char, Boolean]. The reason tuples have this restriction is that they need to be able to handle a non-homogeneous types.
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How to create relationships in MySQL
...s defined as the default storage engine,can check using command (mysql> SELECT @@default_storage_engine;)
– Arun
Feb 18 at 4:00
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Ordering by the order of values in a SQL IN() clause
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Use MySQL's FIELD() function:
SELECT name, description, ...
FROM ...
WHERE id IN([ids, any order])
ORDER BY FIELD(id, [ids in order])
FIELD() will return the index of the first parameter that is equal to the first parameter (other than the first paramet...
An explicit value for the identity column in table can only be specified when a column list is used
...tead of
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table
SELECT *
FROM source_table;
SET IDENTITY_INSERT archive_table OFF;
you need to write
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table (field1, field2, ...)
SELECT field1, field2, ...
FROM source_table;...
MySQL: Fastest way to count number of rows
...s.
The solution is SQL_CALC_FOUND_ROWS. This is usually used when you are selecting rows but still need to know the total row count (for example, for paging).
When you select data rows, just append the SQL_CALC_FOUND_ROWS keyword after SELECT:
SELECT SQL_CALC_FOUND_ROWS [needed fields or *] FROM t...
Regex to validate password strength
... wonder why not using quantifiers? At least 1 special, 1 number, 1 special char, 8 character: ^(?=.*([A-Z]){1,})(?=.*[!@#$&*]{1,})(?=.*[0-9]{1,})(?=.*[a-z]{1,}).{8,100}$
– RockOnGom
Oct 15 '18 at 7:48
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How do you change the server header returned by nginx?
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## vi src/http/ngx_http_header_filter_module.c (lines 48 and 49)
static char ngx_http_server_string[] = "Server: MyDomain.com" CRLF;
static char ngx_http_server_full_string[] = "Server: MyDomain.com" CRLF;
March 2011 edit: Props to Flavius below for pointing out a new option, replacing Nginx's ...
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
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mysql update column with value from another table
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Second possibility is,
UPDATE TableB
SET TableB.value = (
SELECT TableA.value
FROM TableA
WHERE TableA.name = TableB.name
);
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How do I assign an alias to a function name in C++?
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typedef int (*printf_alias)(const char*, ...);
printf_alias holler = std::printf;
Should do you fine.
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