大约有 40,000 项符合查询结果（耗时：0.0320秒） [XML]
MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
...
Rewrite the query into this
SELECT st1.*, st2.relevant_field FROM sometable st1
INNER JOIN sometable st2 ON (st1.relevant_field = st2.relevant_field)
GROUP BY st1.id /* list a unique sometable field here*/
HAVING COUNT(*) > 1
I think st2.relevant_...
How to import CSV file data into a PostgreSQL table?
...iter '','' quote ''"'' csv ', csv_path);
iter := 1;
col_first := (select col_1 from temp_table limit 1);
-- update the column names based on the first row which has the column names
for col in execute format('select unnest(string_to_array(trim(temp_table::text, ''()''), '','')) fro...
SQL: deleting tables with prefix
...r you:
In the MySQL shell or through PHPMyAdmin, use the following query
SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' )
AS statement FROM information_schema.tables
WHERE table_name LIKE 'myprefix_%';
This will generate a DROP statement which you can than copy and execut...
C# Sanitize File Name
...sWith("°")) name = name.CropRight(1) + ".";
return name;
}
You can select your own look-a-likes. I used the Character Map app in windows to select mine %windir%\system32\charmap.exe
As I make adjustments through discovery, I will update this code.
...
How to make an OpenGL rendering context with transparent background?
... 0);
assert(hbmpDIB);
assert(bmp_cnt);
if(hbmpDIB)
SelectObject(pdcDIB, hbmpDIB);
}
BOOL CreateHGLRC()
{
DWORD dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_BITMAP;
PIXELFORMATDESCRIPTOR pfd ;
memset(&pfd,0, sizeof(PIXELFORMATDESCRIPTOR)) ;
pfd.nSize = size...
Generate list of all possible permutations of a string
...re x and y is how you define them and r is the number of characters we are selecting from --if I am understanding you correctly. You should definitely generate these as needed and not get sloppy and say, generate a powerset and then filter the length of strings.
The following definitely isn't the b...
Append values to a set in Python
...
You can also use the | operator to concatenate two sets (union in set theory):
>>> my_set = {1}
>>> my_set = my_set | {2}
>>> my_set
{1, 2}
Or a shorter form using |=:
>>> my_set = {1}
>>> my_set |= {2}
>>> my_set
{1, 2}
N...
How do you create a random string that's suitable for a session ID in PostgreSQL?
...sion verification using PostgreSQL. I know I can get a random number with SELECT random() , so I tried SELECT md5(random()) , but that doesn't work. How can I do this?
...
Base64 encoding in SQL Server 2005 T-SQL
...the same:
-- Encode the string "TestData" in Base64 to get "VGVzdERhdGE="
SELECT
CAST(N'' AS XML).value(
'xs:base64Binary(xs:hexBinary(sql:column("bin")))'
, 'VARCHAR(MAX)'
) Base64Encoding
FROM (
SELECT CAST('TestData' AS VARBINARY(MAX)) AS bin
) AS bin_sql_server_t...
MySQL - How to select data by string length
...
select LENGTH('Ö'); results 2!! András Szepesházi's answer is the correct one!
– fubo
Oct 24 '13 at 13:59
...