大约有 6,100 项符合查询结果（耗时：0.0234秒） [XML]
SQL: IF clause within WHERE clause
...tside the SELECT
IF (IsNumeric(@OrderNumber)) = 1
BEGIN
SELECT * FROM Table
WHERE @OrderNumber = OrderNumber
END ELSE BEGIN
SELECT * FROM Table
WHERE OrderNumber LIKE '%' + @OrderNumber
END
3) Using a long string, compose your SQL statement conditionally, and then use EXEC
The 3r...
How to rename a single column in a data.frame?
...estion, but it is worth noting that you can now use setnames from the data.table package.
library(data.table)
setnames(DF, "oldName", "newName")
# or since the data.frame in question is just one column:
setnames(DF, "newName")
# And for reference's sake, in general (more than once column)
nms ...
Selecting a row of pandas series/dataframe by integer index
...ing @HYRY, see the new docs in 0.11
http://pandas.pydata.org/pandas-docs/stable/indexing.html
Here we have new operators, .iloc to explicity support only integer indexing, and .loc to explicity support only label indexing
e.g. imagine this scenario
In [1]: df = pd.DataFrame(np.random.rand(5,2),i...
How to do SQL Like % in Linq?
...L2E v1 (3.5) will translate into a t-sql expression that will force a full table scan on the table you're querying unless there is another better discriminator in your where clause or join filters.
Update: This is fixed in EF/L2E v4 (.net 4.0), so it will generate a SQL LIKE just like L2S does.
...
ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'db'
...'localhost';
Syntax:
mysql> grant all privileges on `database_name`.`table_name` to 'user_name'@'hostname';
Note:
hostname can be IP address, localhost, 127.0.0.1
In database_name/table_name, * means all databases
In hostname, to specify all hosts use '%'
Step [3]: Get ou...
How to display a dynamically allocated array in the Visual Studio debugger?
...Memory). Specify a memory start address =
m4x4
This displays data in a table, which is better for two and three dimensional matrices:
Right-click on the Memory window to determine how the binary data is visualized. Choices are limited to integers, floats and some text encodings.
...
Disable migrations when running unit tests in Django 1.7
...been run, the "migrate" command treats
an app as unmigrated, and creates tables directly from the models just
like syncdb did in 1.6. I defined a new settings module just for unit
tests called "settings_test.py", which imports * from the main
settings module and adds this line:
MIGRATIO...
How to query MongoDB with “like”?
... Actually, it depends. If the query doesn't use an index, and must do a table scan, then it can certainly be expensive. If you're doing a 'starts with' regex query, then that can use an index. Best to run an explain() to see what's happening.
– Kyle Banker
J...
Setting direction for UISwipeGestureRecognizer
...Apple saying that the behavior works as was intended.
So for example in a table view you can swipe left or right in a table view cell to trigger 'delete' (this would have directions of the swipe gesture set to left and right)
This means that the original workaround is the way it's supposed to be u...
Double exclamation points? [duplicate]
... then it may not be 0 but some other falsy value. See the following truth table:
Truth Table for javascript
'' == '0' // false
0 == '' // true
0 == '0' // true
false == 'false' // false
false == '0' // true
fa...