大约有 41,000 项符合查询结果（耗时：0.0340秒） [XML]
Is there any difference between GROUP BY and DISTINCT
...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
How to initialize a struct in accordance with C programming language standards
...lize a struct this way:
typedef struct Item {
int a;
float b;
char* name;
} Item;
int main(void) {
Item item = { 5, 2.2, "George" };
return 0;
}
An important thing to remember, at the moment you initialize even one object/ variable in the struct, all of its other variables wi...
How do you connect to multiple MySQL databases on a single webpage?
...d);
$dbh2 = mysql_connect($hostname, $username, $password, true);
mysql_select_db('database1', $dbh1);
mysql_select_db('database2', $dbh2);
Then to query database 1 pass the first link identifier:
mysql_query('select * from tablename', $dbh1);
and for database 2 pass the second:
mysql_query...
Get top n records for each group of grouped results
...ould need to specify the group number and add queries for each group:
(
select *
from mytable
where `group` = 1
order by age desc
LIMIT 2
)
UNION ALL
(
select *
from mytable
where `group` = 2
order by age desc
LIMIT 2
)
There are a variety of ways to do this, see this articl...
How can I remove or replace SVG content?
...
Here is the solution:
d3.select("svg").remove();
This is a remove function provided by D3.js.
share
|
improve this answer
|
...
select into in mysql
...
Use the CREATE TABLE SELECT syntax.
http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html
CREATE TABLE new_tbl SELECT * FROM orig_tbl;
share
|
...
Receiving “fatal: Not a git repository” when attempting to remote add a Git repo
...nd then I did this:
echo 'ref: refs/heads/ML_#94_FILTER_TYPES_AND_SPECIAL_CHARS' > .git/HEAD
It worked.
share
|
improve this answer
|
follow
|
...
Regular expression to match a line that doesn't contain a word
...ould do), but still, it is possible.
And if you need to match line break chars as well, use the DOT-ALL modifier (the trailing s in the following pattern):
/^((?!hede).)*$/s
or use it inline:
/(?s)^((?!hede).)*$/
(where the /.../ are the regex delimiters, i.e., not part of the pattern)
If t...
Any way to select without causing locking in MySQL?
...s/22-mysql-with-nolock.aspx
in MS SQL Server you would do the following:
SELECT * FROM TABLE_NAME WITH (nolock)
and the MYSQL equivalent is
SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT * FROM TABLE_NAME ;
SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ ;
EDIT
Mic...
How do I capitalize first letter of first name and last name in C#?
...
TextInfo.ToTitleCase() capitalizes the first character in each token of a string.
If there is no need to maintain Acronym Uppercasing, then you should include ToLower().
string s = "JOHN DOE";
s = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(s.ToLower());
// Produce...