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How do you version your database schema? [closed]
... sure that schema changes are always additive. So I don't drop columns and tables, because that would zap the data and cannot be rolled back later. This way the code that uses the database can be rolled back without losing data or functionality.
I have a migration script that contains statements th...
Handling an empty UITableView. Print a friendly message
I have a UITableView that in some cases it is legal to be empty. So instead of showing the
background image of the app, I would prefer to print a friendly message in the screen, such as:
...
Why all the Active Record hate? [closed]
...problem that I see with Active Records is, that it's always just about one table
Code:
class Person
belongs_to :company
end
people = Person.find(:all, :include => :company )
This generates SQL with LEFT JOIN companies on companies.id = person.company_id, and automatically generates assoc...
Storing SHA1 hash values in MySQL
...ary.
I compared storage requirements for BINARY(20) and CHAR(40).
CREATE TABLE `binary` (
`id` int unsigned auto_increment primary key,
`password` binary(20) not null
);
CREATE TABLE `char` (
`id` int unsigned auto_increment primary key,
`password` char(40) not null
);
With milli...
How to get all Errors from ASP.Net MVC modelState?
...
During debugging I find it useful to put a table at the bottom of each of my pages to show all ModelState errors.
<table class="model-state">
@foreach (var item in ViewContext.ViewData.ModelState)
{
if (item.Value.Errors.Any())
{
...
How do I reset a sequence in Oracle?
...e to call the thing resetting the sequence back to the max ID used in some table. I end up calling this proc from another script which executes multiple calls for a whole bunch of sequences, resetting nextval back down to some level which is high enough to not cause primary key violations where I'm...
Optimal way to concatenate/aggregate strings
...r,
COUNT(*) OVER (PARTITION BY ID) AS NameCount
FROM dbo.SourceTable
),
Concatenated AS
(
SELECT
ID,
CAST(Name AS nvarchar) AS FullName,
Name,
NameNumber,
NameCount
FROM Partitioned
WHERE NameNumber = 1
UNION ALL
SELECT...
C++实现一款简单完整的聊天室服务器+客户端 - C/C++ - 清泛网 - 专注C/C++及内核技术
...
m_ip.SetAddress(127,0,0,1);
return TRUE; // 除非将焦点设置到控件，否则返回 TRUE
}
void CClientDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal();
}
else
{
CDialog::OnSysCommand(nID, lPar...
trying to align html button at the center of the my page [duplicate]
...
I've really taken recently to display: table to give things a fixed size such as to enable margin: 0 auto to work. Has made my life a lot easier. You just need to get past the fact that 'table' display doesn't mean table html.
It's especially useful for responsiv...
Advantage of switch over if-else statement
...tree (saves compares and jumps in the average case) or simply build a jump-table (works without compares at all).
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