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How do you write a migration to rename an ActiveRecord model and its table in Rails?
...ble_name
end
end
I had to go and rename the model declaration file manually.
Edit:
In Rails 3.1 & 4, ActiveRecord::Migration::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rena...
How to get the name of a function in Go?
...
@themihai I don't know, the sentence I quoted is all the docs at golang.org/pkg/reflect/#Value.Pointer say about this. But the quote seems to indicate that one could get the same pointer for different functions, doesn't it? And if this is the case, GetFunctionName might r...
O(nlogn) Algorithm - Find three evenly spaced ones within binary string
...
Finally! Following up leads in sdcvvc's answer, we have it: the O(n log n) algorithm for the problem! It is simple too, after you understand it. Those who guessed FFT were right.
The problem: we are given a binary string S of l...
Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
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Avoid duplicates in INSERT INTO SELECT query in SQL Server
...
Using NOT EXISTS:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1.name
FROM TABLE_1 t1
WHERE NOT EXISTS(SELECT id
FROM TABLE_2 t2
WHERE t2.id = t1.id)
Using NOT IN:
INSERT INTO TABLE_2
(id, name)
SELECT t...
How to filter object array based on attributes?
...art of the new ECMAScript 5th Edition standard, and can be found on almost all modern browsers.
For IE, you can include the following method for compatibility:
if (!Array.prototype.filter) {
Array.prototype.filter = function(fun /*, thisp*/) {
var len = this.length >>> 0;
if (ty...
How to verify that method was NOT called in Moq?
...
Run a verify after the test which has a Times.Never enum set. e.g.
_mock.Object.DoSomething()
_mock.Verify(service => service.ShouldntBeCalled(), Times.Never);
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Apache not starting on MAMP Pro
.... Go to bin -> apache2 -> bin.
Then rename the file from envvars to _envvars.
I also came across another problem of it not working correctly. Make sure the ports are Apache defaults, NOT MAMP defaults (port 80 etc). If it works straight away, this should not apply to you.
...
HAXM 安装/启动失败？ - App Inventor 2 离线版 - 清泛IT社区，为创新赋能！
报错如下：
emulator: Android emulator version 30.3.5.0 (build_id 7033400) (CL:N/A)
127.0.0.1 - - [01/Apr/2025 16:55:37] "GET /echeck/ HTTP/1.1" 200 39
handleCpuAcceleration: feature check for hvf
emulator: ERROR: x86_64 emulation currently requires hardware acceleration!
CPU accel...
Why doesn't String switch statement support a null case?
...st by Christian Hujer has some insightful speculation about why null isn't allowed in switches (although it centers on the enum switch rather than the String switch):
Under the hood, the switch statement will typically compile to a tablesswitch byte code. And the "physical" argument to switch as we...