大约有 42,000 项符合查询结果（耗时：0.0346秒） [XML]
MySql Table Insert if not exist otherwise update
...p using:
replace into last_recogs (id, hasher_id, hash_id, last_recog)
select l.* from
(select id, hasher_id, hash_id, [new_value] from last_recogs
where hasher_id in (select id from hashers where name=[hasher_name])
and hash_id in (select id from hashes where name=[hash_name])
...
Simple way to convert datarow array to datatable
...For .Net Framework 3.5+
DataTable dt = new DataTable();
DataRow[] dr = dt.Select("Your string");
DataTable dt1 = dr.CopyToDataTable();
But if there is no rows in the array, it can cause the errors such as The source contains no DataRows. Therefore, if you decide to use this method CopyToDataTable...
Permission denied (publickey) when SSH Access to Amazon EC2 instance [closed]
...these steps:
Access to AWS Management Console
Open Elastic Beanstalk Tab
Select your application from All Applications Tab
From left side menù select Configuration
Click on the Instances Gear
In Server Form check the EC2 Key Pair input and select your new Key Pair. You may have to refresh the lis...
Edit a commit message in SourceTree Windows (already pushed to remote)
...most recent commit) using SourceTree for Windows version 1.5.2.0:
Step 1
Select the commit immediately before the commit that you want to edit.
For example, if I want to edit the commit with message "FOOBAR!" then I need
to select the commit that comes right before it:
Step 2
Right-click on th...
Compare two files in Visual Studio
... the desktop. That's all!
Usage:
Open the Windows explorer via Win + E
Select two files to compare in the explorer
Drag and drop them as shown in the animation below:
After a few seconds (depending on the launch time of Visual Studio), the results will be shown in Visual Studio:
Note: It d...
How can I get dict from sqlite query?
...":memory:")
con.row_factory = dict_factory
cur = con.cursor()
cur.execute("select 1 as a")
print cur.fetchone()["a"]
or follow the advice that's given right after this example in the docs:
If returning a tuple doesn’t suffice
and you want name-based access to
columns, you should consider...
MySQL: @variable vs. variable. What's the difference?
...ialize this variable with a SET statement or inside a query:
SET @var = 1
SELECT @var2 := 2
When you develop a stored procedure in MySQL, you can pass the input parameters and declare the local variables:
DELIMITER //
CREATE PROCEDURE prc_test (var INT)
BEGIN
DECLARE var2 INT;
SET var2 =...
varbinary to string on SQL Server
...AST it
declare @b varbinary(max)
set @b = 0x5468697320697320612074657374
select cast(@b as varchar(max)) /*Returns "This is a test"*/
This is the equivalent of using CONVERT with a style parameter of 0.
CONVERT(varchar(max), @b, 0)
Other style parameters are available with CONVERT for differ...
Linq with group by having count
...
from c in db.Company
group c by c.Name into grp
where grp.Count() > 1
select grp.Key
Or, using the method syntax:
Company
.GroupBy(c => c.Name)
.Where(grp => grp.Count() > 1)
.Select(grp => grp.Key);
...
How to select the row with the maximum value in each group
In a dataset with multiple observations for each subject I want to take a subset with only the maximum data value for each record. For example, with a following dataset:
...