大约有 47,000 项符合查询结果（耗时：0.0388秒） [XML]
XPath OR operator for different nodes
...
If you want to select only one of two nodes with union operator, you can use this solution:
(//bookstore/book/title | //bookstore/city/zipcode/title)[1]
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SQL update query using joins
...common table expression (since you're already on SQL 2005):
with cte as (
select
im.itemid
,im.sku as iSku
,gm.SKU as GSKU
,mm.ManufacturerId as ManuId
,mm.ManufacturerName
,im.mf_item_number
,mm.ManufacturerID
, <your other field>
from
item_master im, gro...
VC DDE（Dynamic Data Exchange）与EXCEL连接 - C/C++ - 清泛网 - 专注C/C++及内核技术
...char szItem5[] = "R3C1"; char szData5[16] = "0";
//char szCmd2[] = "[SELECT(\"R3C1\")][FONT.PROPERTIES(,\"Bold\")][SAVE()][QUIT()]";
char szCmd2[] = "[SELECT(\"R3C1\")][FONT.PROPERTIES(,\"Bold\")]";
char szCmd3[] = "[SELECT(\"R3C1\")][FONT.PROPERTIES(,\"Bold\")]";
int i,j,k;
char...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...ata.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which are in both data frames:
a1Ina2 <- sqldf('SELECT * FROM a1 INTERSECT SELECT * FROM a2')
The new version of dplyr has a function, anti_join, for exactly the...
How to reformat JSON in Notepad++?
...,
"onclick" : "CloseDoc()"
}
]
}
}
}
Tip: Select the code you want to reformat, then Plugins | JSTool | JSFormat.
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How do I simulate a hover with a touch in touch enabled browsers?
...for added usefulness, add this to your CSS as well:
.hover {
-webkit-user-select: none;
-webkit-touch-callout: none;
}
To stop the browser asking you to copy/save/select the image or whatever.
Easy!
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Increment value in mysql update query
...ion to numbers.
To demonstrate, the following will produce the result 6:
SELECT ' 05.05 '+'.95';
String concatenation in MySQL requires the CONCAT() function so there is no ambiguity here and MySQL converts the strings to floats and adds them together.
I actually think the reason the initial q...
How do I specify different layouts for portrait and landscape orientations?
...mes depending on orientation and resolution, the device will automatically select the right one for its screen settings
More info here:
http://developer.android.com/guide/practices/screens_support.html
under "Resource directory qualifiers for screen size and density"
...
Hidden Features of MySQL
...that has an integer type,
you can also refer to the column as "_rowid" in SELECT statements.
In MySQL, the name of a PRIMARY KEY is PRIMARY
Currently, only InnoDB (v5.1?) tables support foreign keys.
Usually, you create all the indexes you need when you are creating tables.
Any column declared...
data.table vs dplyr: can one do something well the other can't or does poorly?
... ## data.table syntax
left_join(DT2, DT1) ## dplyr syntax
# 2. select columns while join
DT1[DT2, .(z, i.mul)]
left_join(select(DT2, x, y, mul), select(DT1, x, y, z))
# 3. aggregate while join
DT1[DT2, .(sum(z) * i.mul), by = .EACHI]
DF1 %>% group_by(x, y) %>% summarise(z = su...