大约有 48,000 项符合查询结果（耗时：0.0954秒） [XML]
How can you represent inheritance in a database?
...is is how you would have to query all the policies regardless of the type:
SELECT date_issued, other_common_fields, 'MOTOR' AS type
FROM policies_motor
UNION ALL
SELECT date_issued, other_common_fields, 'PROPERTY' AS type
FROM policies_property;
Note how adding new subtypes woul...
Flask SQLAlchemy query, specify column names
How do I specify the column that I want in my query using a model (it selects all columns by default)? I know how to do this with the sqlalchmey session: session.query(self.col1) , but how do I do it with with models? I can't do SomeModel.query() . Is there a way?
...
What is RemoteSystemsTempFiles in Eclipse?
...s quite simple:
In only 2 steps: install the plug-in then disable it.
select Help -> Install New Software, then choose the "http://download.eclipse.org/releases/[your-version-here]", then enter remote in the filter box.
search for the Remote System Explorer End-User Runtime & co. Probab...
Connect to Amazon EC2 file directory using Filezilla and SFTP
...SFTP, Click "Add key file”
Browse to the location of your .pem file and select it.
A message box will appear asking your permission to convert the file into ppk format. Click Yes, then give the file a name and store it somewhere.
If the new file is shown in the list of Keyfiles, then continue t...
CSS Selector “(A or B) and C”?
...rmit groupings. It's essentially the lowest-precedence logical operator in selectors, so you must use .a.c,.b.c.
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Get the new record primary key ID from MySQL insert query?
...
Eg:
INSERT INTO table_name (col1, col2,...) VALUES ('val1', 'val2'...);
SELECT LAST_INSERT_ID();
This will get you back the PRIMARY KEY value of the last row that you inserted:
The ID that was generated is maintained in the server on a per-connection basis. This means that the value returne...
Is it possible to for SQL Output clause to return a column not being inserted?
...d.ReportOptionId
INTO @PracticeReportOption (PracticeId, ReportOptionId)
SELECT field1, field2
FROM @ReportOption
with
MERGE INTO ReportOption USING @ReportOption AS temp ON 1 = 0
WHEN NOT MATCHED THEN
INSERT (field1, field2)
VALUES (temp.Field1, temp.Field2)
OUTPUT temp.Practice...
getting type T from IEnumerable
... t.GetGenericTypeDefinition() == typeof(IEnumerable<>))
.Select(t => t.GetGenericArguments()[0]);
}
Some objects implement more than one generic IEnumerable so it is necessary to return an enumeration of them.
Edit: Although, I have to say, it's a terrible idea for a class to...
Which SQL query is faster? Filter on Join criteria or Where clause?
...INNER JOIN with a LEFT JOIN.
In your very case this will look like this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x
ON x.TableAID = a.ID
AND a.ID = 1
LEFT JOIN
TableB b
ON x.TableBID = b.ID
or this:
SELECT *
FROM TableA a
LEFT JOIN
TableXRef x...
Change / Add syntax highlighting for a language in Sublime 2/3
...uage(s) you want) into your Packages directory - find it on your system by selecting Preferences -> Browse Packages.... Then, simply do a git pull in the original repo directory from time to time to refresh any changes, and you can enjoy the latest and greatest! I should note that the repo uses t...