大约有 44,000 项符合查询结果（耗时：0.0577秒） [XML]
How to get index using LINQ? [duplicate]
... vs. Any(Func<T, bool>), ConvertAll(Converter<T, TOutput>) vs. Select(Func<T1, T2>), etc.
– SLaks
Mar 18 '10 at 17:28
...
SQL Server Text type vs. varchar data type [closed]
...ts in your database
If you do not search on the value of the column
If you select this column rarely and do not join on it.
VARCHAR is good:
If you store little strings
If you search on the string value
If you always select it or use it in joins.
By selecting here I mean issuing any queries that ...
SQL Server IN vs. EXISTS Performance
...execution operation, to get their results.
An example:
Query 1 ( plan )
select * from dt where dt.customer in (select c.code from customer c where c.active=0)
Query 2 ( plan )
select * from dt where exists (select 1 from customer c where c.code=dt.customer and c.active=0)
...
How to move the cursor word by word in the OS X Terminal
...e sequences for you:
Open Terminal preferences (cmd+,);
At Settings tab, select Keyboard and double-click ⌥ ← if it's there, or add it if it's not.
Set the modifier as desired, and type the shortcut key in the box: esc+B, generating the text \033b (you can't type this text manually).
Repeat fo...
Pythonic way to create a long multi-line string
...de commas between the string segments, then it will be a tuple.
query = ('SELECT action.descr as "action", '
'role.id as role_id,'
'role.descr as role'
' FROM '
'public.role_action_def,'
'public.role,'
'public.record_def, '
'public.ac...
Cannot create or edit Android Virtual Devices (AVD) from Eclipse, ADT 22.6
...lone button worked and I was able to successfully edit the clone.
Steps:
Select a Device by Google
Click the "Clone..." button
A window will pop up, click "Clone device"
Select the newly cloned Device, it should say "... by User"
Click the "Edit" button on the side
There you have it...
LINQ with groupby and count
...(var line in data.GroupBy(info => info.metric)
.Select(group => new {
Metric = group.Key,
Count = group.Count()
})
.OrderBy(x => x.Metric))
{
Console.Wri...
Package doesn't exist error in intelliJ
...ing all modules:
open File > Project Structure...,
go to Modules tab,
select all modules and press the remove button,
then removing all remaining Maven modules from Maven tool window:
select all modules,
right click on them,
press Remove projects,
and then adding them again in Project to...
Show data on mouseover of circle
...and you don't need the mousehandler. The code would be something like
vis.selectAll("circle")
.data(datafiltered).enter().append("svg:circle")
...
.append("svg:title")
.text(function(d) { return d.x; });
If you want fancier tooltips, you could use tipsy for example. See here for an ex...
Transaction isolation levels relation with locks on table
... writes data and commit/rollback (depending on results). B just executes a SELECT statement to read data. C reads and updates data. All these process work on the same table T.
READ UNCOMMITTED - no lock on the table. You can read data in the table while writing on it. This means A writes data (unc...