大约有 48,000 项符合查询结果（耗时：0.0863秒） [XML]
belongs_to through associations
...
I'd like to know myself. Everything I tried fired 3 selects. You can specify a "-> { joins :something }" lambda on an association. The join is fired but subsequently another select anyway. I wasn't able to tune this up.
– Renra
Oct 21 ...
Is there a way to get the XPath in Google Chrome?
...asking "how to get an xpath string for an element?", rather than "how do i select by xpath?" wasn't he?
– Max Williams
Jan 3 '12 at 11:05
3
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How to log PostgreSQL queries?
...ement = 'all'
#logging_collector = off to logging_collector = on
Optional: SELECT set_config('log_statement', 'all', true);
sudo /etc/init.d/postgresql restart or sudo service postgresql restart
Fire query in postgresql select 2+2
Find current log in /var/lib/pgsql/9.2/data/pg_log/
The log files t...
ASP.NET MVC Yes/No Radio Buttons with Strongly Bound Model MVC
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The second parameter is selected, so use the ! to select the no value when the boolean is false.
<%= Html.RadioButton("blah", !Model.blah) %> Yes
<%= Html.RadioButton("blah", Model.blah) %> No
...
How to convert linq results to HashSet or HashedSet
...f T explicitly:
var query = from i in Enumerable.Range(0, 10)
select new { i, j = i + 1 };
var resultSet = query.ToHashSet();
You can't do that with an explicit call to the HashSet<T> constructor. We're relying on type inference for generic methods to do it for us.
Now you coul...
How to find what code is run by a button or element in Chrome using Developer Tools
... tab, and on the right find Event
Listener Breakpoints:
Expand Mouse and select click
Now click the element (execution should pause), and you are now debugging the code. You can go through all code pressing F11 (which is Step in). Or go back a few jumps in the stack. There can be a ton of jumps
...
PreparedStatement with list of parameters in a IN clause [duplicate]
... possibleValue.size(); i++ ) {
builder.append("?,");
}
String stmt = "select * from test where field in ("
+ builder.deleteCharAt( builder.length() -1 ).toString() + ")";
PreparedStatement pstmt = ...
And then happily set the params
int index = 1;
for( Object o : possibleVal...
How can I clear the SQL Server query cache?
...et DBID from one database name first
DECLARE @intDBID INT;
SET @intDBID = (SELECT [dbid]
FROM master.dbo.sysdatabases
WHERE name = N'AdventureWorks2014');
DBCC FLUSHPROCINDB (@intDBID);
7. Clear plan cache for the current database
USE AdventureWorks2014;
GO
-- New...
What's the difference between VARCHAR and CHAR?
...CHAR(10),
Street VARCHAR(10));
Insert into temp
values('Pune','Oxford');
select length(city), length(street) from temp;
Output will be
length(City) Length(street)
10 6
Conclusion: To use storage space efficiently must use VARCHAR Instead CHAR if variable length is ...
Give all the permissions to a user on a DB
...%', ( -- use instead of EXECUTE to see generated commands
EXECUTE (
SELECT string_agg(format('GRANT USAGE ON SCHEMA %I TO my_user', nspname), '; ')
FROM pg_namespace
WHERE nspname <> 'information_schema' -- exclude information schema and ...
AND nspname NOT LIKE 'pg\_%' ...