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Switch on Enum in Java [duplicate]
...r speed, the switch statement approach might be faster because it's just a table lookup in the bytecode. With your approach, you have to push a new function onto the stack. It's a micro-optimization, but if speed is super important it's something to keep in mind.
– DIMMSum
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ASP.NET MVC 5 - Identity. How to get current ApplicationUser
... having an extra context for starters, but going forward the user database tables change (3 times in the past 2 years) but the API is consistent. For example the users table is now called AspNetUsers in Identity Framework, and the names of several primary key fields kept changing, so the code in sev...
What happens when a computer program runs?
...me systems)
+---------+
| text | program code, this is the actual executable code that is running.
+---------+
This is the general process address space on many common virtual-memory systems. The "hole" is the size of your total memory, minus the space taken up by all the other areas; this gi...
postgresql COUNT(DISTINCT …) very slow
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You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
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SQLite string contains other string query
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Using LIKE:
SELECT *
FROM TABLE
WHERE column LIKE '%cats%' --case-insensitive
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On duplicate key ignore? [duplicate]
...).
Instead, since in your example tag is the unique key, use:
INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c') ON DUPLICATE KEY UPDATE tag=tag;
on duplicate key produces:
Query OK, 0 rows affected (0.07 sec)
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Javascript. Assign array values to multiple variables? [duplicate]
...t in languages such as Perl and Python.
Unfortunately, according to this table of versions, JavaScript 1.7 has not been implemented in Chrome. But it should be there in:
FireFox 2.0+
IE 9
Opera 11.50.
Try it for yourself in this jsfiddle: http://jsfiddle.net/uBReg/
I tested this on Chrome (f...
SQL WITH clause example [duplicate]
...me assigned to the sub-query is treated as though it was an inline view or table. The SQL WITH clause is basically a drop-in replacement to the normal sub-query.
Syntax For The SQL WITH Clause
The following is the syntax of the SQL WITH clause when using a single sub-query alias.
WITH <alias_n...
Is there a way to “limit” the result with ELOQUENT ORM of Laravel?
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Also, we can use it following ways
To get only first
$cat_details = DB::table('an_category')->where('slug', 'people')->first();
To get by limit and offset
$top_articles = DB::table('an_pages')->where('status',1)->limit(30)->offset(0)->orderBy('id', 'DESC')->get();
$remaining...
Discuz! X3 论坛标题字数突破80的限制 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...你的表的前缀，还有修改前一定要备份！！！）
ALTER TABLE `pre_forum_post` CHANGE `subject` `subject` varchar(255) NOT NULL;
ALTER TABLE `pre_forum_rsscache` CHANGE `subject` `subject` varchar(255) NOT NULL;
ALTER TABLE `pre_forum_thread` CHANGE `subject` `subject` varchar(255...