大约有 43,000 项符合查询结果（耗时：0.0378秒） [XML]
Select rows which are not present in other table
...task, all of them standard SQL.
NOT EXISTS
Often fastest in Postgres.
SELECT ip
FROM login_log l
WHERE NOT EXISTS (
SELECT -- SELECT list mostly irrelevant; can just be empty in Postgres
FROM ip_location
WHERE ip = l.ip
);
Also consider:
What is easier to read in EXISTS...
Case insensitive searching in Oracle
...NLS_COMP and NLS_SORT session parameters:
SQL> SET HEADING OFF
SQL> SELECT *
2 FROM NLS_SESSION_PARAMETERS
3 WHERE PARAMETER IN ('NLS_COMP', 'NLS_SORT');
NLS_SORT
BINARY
NLS_COMP
BINARY
SQL>
SQL> SELECT CASE WHEN 'abc'='ABC' THEN 1 ELSE 0 END AS GOT_MATCH
2 FROM DUAL;
...
Insert the carriage return character in vim
...tored a file in Unix ( \n newlines). I need to insert the carriage return character ( U+000D aka \r ). When I try to paste it from the clipboard ( "+p ) or type it using Ctrl + Shift + u - 000d , the linefeed is inserted ( U+000A ).
...
Resetting a multi-stage form with jQuery
...n, :submit, :reset, :hidden')
.val('')
.removeAttr('checked')
.removeAttr('selected');
Which might work for a lot of cases, including for the OP, but as pointed out in the comments and in other answers, will clear radio/checkbox elements from any value attributes.
A more correct answer (but not per...
How do I change read/write mode for a file using Emacs?
... (save-excursion
(unless (= return-value 0)
(goto-char (point-min))
(end-of-line)
(if (= (point-min) (point))
(error "Command failed: %s%s" command
(with-output-to-string
(dolist (arg args)
(pri...
How to select date from datetime column?
...ry.
Use BETWEEN or >, <, = operators which allow to use an index:
SELECT * FROM data
WHERE datetime BETWEEN '2009-10-20 00:00:00' AND '2009-10-20 23:59:59'
Update: the impact on using LIKE instead of operators in an indexed column is high. These are some test results on a table with 1,...
How to get object size in memory? [duplicate]
...would know, Int32 and float are four
bytes, double and DateTime 8 bytes, char is actually two bytes (not
one byte), and so on. String is a bit more complex, 2*(n+1), where n
is the length of the string. For objects, it will depend on their
members: just sum up the memory requirement of all i...
SQL query to select dates between two dates
...
you should put those two dates between single quotes like..
select Date, TotalAllowance from Calculation where EmployeeId = 1
and Date between '2011/02/25' and '2011/02/27'
or can use
select Date, TotalAllowance from Calculation where EmployeeId = 1
and Da...
Adding HTML entities using CSS content
... edited Apr 23 '18 at 5:15
Charlie
6,5134545 silver badges5050 bronze badges
answered Oct 10 '08 at 7:27
...
Named capturing groups in JavaScript regex?
...if the order of the groups changes? Also, it's annonying to put this extra chars on the other groups...
– Alba Mendez
Nov 9 '12 at 15:45
...