大约有 37,000 项符合查询结果（耗时：0.0279秒） [XML]
Using margin:auto to vertically-align a div
...he three elements have to be nested like so:
.container {
display: table;
height: 100%;
position: absolute;
overflow: hidden;
width: 100%;
}
.helper {
#position: absolute;
#top: 50%;
display: table-cell;
vertical-align: middle;
}
.content {
#position: rela...
How many characters can UTF-8 encode?
...
According to this table* UTF-8 should support:
231 = 2,147,483,648 characters
However, RFC 3629 restricted the possible values, so now we're capped at 4 bytes, which gives us
221 = 2,097,152 characters
Note that a good chunk of those chara...
Postgresql: Conditionally unique constraint
... a constraint which enforces uniqueness on a column only in a portion of a table.
2 Answers
...
Why malloc+memset is slower than calloc?
...n parts here: your program, the standard library, the kernel, and the page tables. You already know your program, so...
Memory allocators like malloc() and calloc() are mostly there to take small allocations (anything from 1 byte to 100s of KB) and group them into larger pools of memory. For exam...
When do I need to use Begin / End Blocks and the Go keyword in SQL Server?
...
GO is like the end of a script.
You could have multiple CREATE TABLE statements, separated by GO. It's a way of isolating one part of the script from another, but submitting it all in one block.
BEGIN and END are just like { and } in C/++/#, Java, etc.
They bound a logical block of ...
Getting result of dynamic SQL into a variable for sql-server
...
dynamic version
ALTER PROCEDURE [dbo].[ReseedTableIdentityCol](@p_table varchar(max))-- RETURNS int
AS
BEGIN
-- Declare the return variable here
DECLARE @sqlCommand nvarchar(1000)
DECLARE @maxVal INT
set @sqlCommand = 'SELECT @maxVal...
Is BCrypt a good hashing algorithm to use in C#? Where can I find it? [closed]
...ing through the use of the same encryption key that encrypted it.
Rainbow Table - a lookup table that contains all variations of characters hashed in a specific hashing algorithm.
Salt - a known random string appended to the original string before it is hashed.
For the .NET Framework, Bcrypt does...
How to stop text from taking up more than 1 line?
...
Note: this only works on block elements. If you need to do this to table cells (for example) you need to put a div inside the table cell as table cells have display table-cell not block.
As of CSS3, this is supported for table cells as well.
...
Permanently Set Postgresql Schema Path
... set schema path in Postgres so that I don't every time specify schema dot table e.g. schema2.table .
Set schema path:
3 ...
Should I commit or rollback a read transaction?
...
Suppose I create a temp table, populate it with ids, join it with a data table to select the data that goes with the ids, then delete the temp table. I'm really just reading data, and I don't care what happens to the temp table, since it's temporar...