大约有 40,000 项符合查询结果（耗时：0.0286秒） [XML]
How do I get the size of a java.sql.ResultSet?
...
Do a SELECT COUNT(*) FROM ... query instead.
OR
int size =0;
if (rs != null)
{
rs.last(); // moves cursor to the last row
size = rs.getRow(); // get row id
}
In either of the case, you won't have to loop over the enti...
What is the correct way to restore a deleted file from SVN?
...go to TortoiseSVN -> Merge...
Make sure "Merge a range of revisions" is selected, click Next
In the "Revision range to merge" textbox, specify the revision that removed the file
Check the "Reverse merge" checkbox, click Next
Click Merge
That is completely untested, however.
Edited by OP: Thi...
Visual Studio : short cut Key : Duplicate Line
...ure is now built-in in VS2017: Ctrl + E, V duplicates a line if nothing is selected, or duplicates selection. You can assign it to a different key combination, or find it in the menu:
See this reference for more information.
Pre VS2017, built-in method using clipboard
As @cand mentioned, you ca...
What is the use of the square brackets [] in sql statements?
...
sql also uses square brackets in the like-operator of a select query to limit results using regular expressions. codeproject.com/Articles/33941/SQL-LIKE-Operator
– Jens Frandsen
Sep 4 '13 at 18:49
...
Setting the selected value on a Django forms.ChoiceField
...t hand, but this Q/A comes up for searches related to trying to assign the selected value to a ChoiceField.
If you have already called super().__init__ in your Form class, you should update the form.initial dictionary, not the field.initial property. If you study form.initial (e.g. print self.init...
Equals(=) vs. LIKE
... can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLATE latin1_german2_ci;
+-----------------------------------------+
| 'ä' LIKE 'ae' COLLATE latin1_german2_ci |
+-----------------------------------------+
| 0 |...
SQL Server indexes - ascending or descending, what difference does it make?
...TE INDEX ix_index ON mytable (col1, col2 DESC);
can be used for either:
SELECT *
FROM mytable
ORDER BY
col1, col2 DESC
or:
SELECT *
FROM mytable
ORDER BY
col1 DESC, col2
, but not for:
SELECT *
FROM mytable
ORDER BY
col1, col2
An index on a single colum...
Joining three tables using MySQL
...
Simply use:
select s.name "Student", c.name "Course"
from student s, bridge b, course c
where b.sid = s.sid and b.cid = c.cid
share
|
...
Linq: adding conditions to the where clause conditionally
... && u.Age > 18
&& u.Height > strHeightinFeet
select u;
if (useAge)
query = query.Where(u => u.Age > age);
if (useHeight)
query = query.Where(u => u.Height > strHeightinFeet);
// Build the results at the end
var results = query.Select(u => new DTO...
Comparing Dates in Oracle SQL
...r by using the built-in TO_DATE() function, or a date literal.
TO_DATE()
select employee_id
from employee
where employee_date_hired > to_date('31-DEC-95','DD-MON-YY')
This method has a few unnecessary pitfalls
As a_horse_with_no_name noted in the comments, DEC, doesn't necessarily mean D...