大约有 5,887 项符合查询结果（耗时：0.0276秒） [XML]
Replace Default Null Values Returned From Left Outer Join
I have a Microsoft SQL Server 2008 query that returns data from three tables using a left outer join. Many times, there is no data in the second and third tables and so I get a null which I think is the default for left outer join. Is there a way to replace the default values in the select stateme...
How can I check the size of a collection within a Django template?
...
See https://docs.djangoproject.com/en/stable/ref/templates/builtins/#if : just use, to reproduce their example:
{% if athlete_list %}
Number of athletes: {{ athlete_list|length }}
{% else %}
No athletes.
{% endif %}
...
Host 'xxx.xx.xxx.xxx' is not allowed to connect to this MySQL server
...you cannot figure out why you get
Access denied, remove from the user
table all entries that have Host
values containing wildcards (entries
that contain '%' or '_' characters). A
very common error is to insert a new
entry with Host='%' and
User='some_user', thinking that this
allows...
Printing all global variables/local variables?
... @cpuer: Not necessarily. It only displays the name in the symbol table. For instance, with gcc on Mac a static variable y is renamed to y.1913 on compilation.
– kennytm
Jun 7 '11 at 7:14
...
Should all jquery events be bound to $(document)?
...ent handlers for them. I say that in my answer. If I had a giant 500 row table and had the same button in every row of a particular column, I would use one delegated event handler on the table to serve all the buttons. But if I had 200 elements and they all needed their own unique event handler, ...
【内核源码】linux UDP实现 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...= &sysctl_udp_rmem_min,
.obj_size = sizeof(struct udp_sock),
.h.udp_table = &udp_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udp_setsockopt,
.compat_getsockopt = compat_udp_getsockopt,
#endif
.diag_destroy = udp_abort,
};
bind()
bind()->inet_bind()->udp_v4_get_por...
When is CRC more appropriate to use than MD5/SHA1?
...
I found a study that shows how inappropriate CRC hashes are for hash tables. It also explains the actual characteristics of the algorithm. The study also includes evaluation of other hash algorithms and is a good reference to keep.
The relevant conclusion on CRC for hashes:
CRC32 was neve...
How do I pass JavaScript variables to PHP?
...; tags you can output something more human-friendly (like $row['name'], if table "salaried" have one)
}
?>
</select>
<?php endif ?>
</p>
<p>
<input type="submit" value="Sumbit my choice"/>
</p>
...
ManyRelatedManager object is not iterable
...}
{% empty %}
empty list!
{% endfor %}
UPDATE
If you have a through table, you can access the elements in that table (as detailed here) like so (note, you use the through table name, in lowercase, suffixing _set):
{% for roominfo in participant.roomchoicethru_set.all %}
{{ roominfo.room}} ...
Differences in auto-unboxing between Java 6 vs Java 7
...ve type by unboxing conversion (§5.1.8).
The Java 7 JLS also contains a table (table 5.1) of allowed conversions (this table is not included in the Java 5/6 JLS) from reference types to primitives. This explicitly lists casts from Object to primitives as a narrowing reference conversion with unbo...