大约有 47,000 项符合查询结果（耗时：0.0538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...
How do I drop a foreign key constraint only if it exists in sql server?
...target a foreign key constraint on a specific table, use this:
IF EXISTS (SELECT *
FROM sys.foreign_keys
WHERE object_id = OBJECT_ID(N'dbo.FK_TableName_TableName2')
AND parent_object_id = OBJECT_ID(N'dbo.TableName')
)
ALTER TABLE [dbo.TableName] DROP CONSTRAINT [FK_TableName_TableName2]...
How to find the port for MS SQL Server 2008?
...nfiguration -> Client Protocols -> TCP/IP
double click ( Right click select Properties ) on TCP/IP.
You will find Default Port 1433.
Depending on connection, the port number may vary.
share
|
...
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...
How to use if - else structure in a batch file?
I have a question about if - else structure in a batch file. Each command runs individually, but I couldn't use "if - else" blocks safely so these parts of my programme doesn't work. How can I do make these parts run? Thank you.
...
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...
How to ignore xargs commands if stdin input is empty?
Consider this command:
6 Answers
6
...
Unicode (UTF-8) reading and writing to files in Python
I'm having some brain failure in understanding reading and writing text to a file (Python 2.4).
14 Answers
...
What is the max size of localStorage values?
Since localStorage (currently) only supports strings as values, and in order to do that the objects need to be stringified (stored as JSON-string) before they can be stored, is there a defined limitation regarding the length of the values.
...
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.
share
|
improve this answer
|
follow
|
...