大约有 40,000 项符合查询结果（耗时：0.0721秒） [XML]
When to use EntityManager.find() vs EntityManager.getReference() with JPA
...er, behind the scenes, will call
SELECT NAME, AGE FROM PERSON WHERE PERSON_ID = ?
UPDATE PERSON SET AGE = ? WHERE PERSON_ID = ?
If i call getReference method, JPA provider, behind the scenes, will call
UPDATE PERSON SET AGE = ? WHERE PERSON_ID = ?
And you know why ???
When you call getRefere...
Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
...+ b[k]) for k in set(b) & set(a)])
or even more generic:
def combine_dicts(a, b, op=operator.add):
return dict(a.items() + b.items() +
[(k, op(a[k], b[k])) for k in set(b) & set(a)])
For example:
>>> a = {'a': 2, 'b':3, 'c':4}
>>> b = {'a': 5, 'c':6, 'x':7...
Why can't Python parse this JSON data?
...: "0"
}
],
"masks": {
"id": "valore"
},
"om_points": "value",
"parameters": {
"id": "valore"
}
}
Then you can use your code:
import json
from pprint import pprint
with open('data.json') as f:
data = json.load(f)
pprint(data)
With data, you c...
pandas GroupBy columns with NaN (missing) values
...
No, this is not consistent with R. df %>% group_by will give NA summaries too with a warning which can be avoided by passing the grouping column through fct_explicit_na and then a (Missing) level is created.
– Ravaging Care
Aug 16 '1...
How to list variables declared in script in bash?
...t using temporary files: VARS="`set -o posix ; set`"; source script; SCRIPT_VARS="`grep -vFe "$VARS" <<<"$(set -o posix ; set)" | grep -v ^VARS=`"; unset VARS; . This will also output the vars in a ready-to-save format. The list will include the variables that the script changed (it depends...
Restoring MySQL database from physical files
... a single tablespace *, which by default consist of the 3 files ibdata1, ib_logfile0, and ib_logfile1. for restoring a database, you would also need those files. * per-table tablespaces are possible, but not default
– ax.
Aug 21 '09 at 18:18
...
Populate a Razor Section From a Partial
...n the Scripts section of your view:
@section Scripts
{
@Html.Partial("_Scripts", "ScriptName_For_Partial1")
}
Again, it might not win a beauty prize but it will work.
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Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
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Can't open config file: /usr/local/ssl/openssl.cnf on Windows [duplicate]
...
The solution is running this command:
set OPENSSL_CONF=C:\OpenSSL-Win32\bin\openssl.cfg
or
set OPENSSL_CONF=[path-to-OpenSSL-install-dir]\bin\openssl.cfg
in the command prompt before using openssl command.
Let openssl know for sure where to find its .cfg file.
Al...
How do you run a SQL Server query from PowerShell?
... would use the following. It is what we use at my company.
$ServerName = "_ServerName_"
$DatabaseName = "_DatabaseName_"
$Query = "SELECT * FROM Table WHERE Column = ''"
#Timeout parameters
$QueryTimeout = 120
$ConnectionTimeout = 30
#Action of connecting to the Database and executing the query a...