大约有 37,000 项符合查询结果（耗时：0.0515秒） [XML]
How to round an average to 2 decimal places in PostgreSQL?
...old syntax for casting,
SELECT ROUND(AVG(some_column)::numeric,2)
FROM table;
works with any version of PostgreSQL.
There are a lack of overloads in some PostgreSQL functions, why (???): I think "it is a lack" (!), but @CraigRinger, @Catcall and the PostgreSQL team agree about "pg's historic r...
What datatype to use when storing latitude and longitude data in SQL databases? [duplicate]
... those fields in mysql to benefit from the fact they are integers:
Create Table: CREATE TABLE `Locations` (
`lat` int(10) unsigned NOT NULL,
`lon` int(10) unsigned NOT NULL,
`location` text,
PRIMARY KEY (`lat`,`lon`) USING BTREE,
KEY `index_location` (`locationText`(30))
) ENGINE=InnoDB D...
Convert text into number in MySQL query
... field,CONVERT(SUBSTRING_INDEX(field,'-',-1),UNSIGNED INTEGER) AS num
FROM table
ORDER BY num;
share
|
improve this answer
|
follow
|
...
Which one is the best PDF-API for PHP? [closed]
...
mpdf unfortunately doesn't seem to handle large table cells well. As soon as the content exceeds a page, it starts to scale down, which makes it useless for any project that has big tables. Apart from that; it's easy to use, performant, and well documented.
...
Convert a matrix to a 1 dimensional array
...dimensions of the matrix/array.
Elts_int <- as.matrix(tmp_int) # read.table returns a data.frame as Brandon noted
dim(Elts_int) <- (maxrow_int*maxcol_int,1)
share
|
improve this answer
...
Does opacity:0 have exactly the same effect as visibility:hidden
...s* No No
display: none Yes No No
* Yes inside a table element, otherwise No.
share
|
improve this answer
|
follow
|
...
Can I use GDB to debug a running process?
...so use the "file" command
to specify the program, and to load its symbol table.
NOTE: You may have difficulty attaching to a process due to improved security in the Linux kernel - for example attaching to the child of one shell from another.
You'll likely need to set /proc/sys/kernel/yama/ptr...
Convert data.frame column to a vector?
... of using the '[[' operator is that it works both with data.frame and data.table. So if the function has to be made running for both data.frame and data.table, and you want to extract a column from it as a vector then
data[["column_name"]]
is best.
...
What is the best Distributed Brute Force countermeasure?
...nd since it still beats being locked out of your account, it would be acceptable.
(Also, note that none of this happens if the attack is any less sophisticated than the nasty distributed version I've described here. If the attack is coming from just a few IPs or only hitting a few usernames, it wi...
setting multiple column using one update
How to set multiple columns of a table using update query in mysql?
2 Answers
2
...