大约有 45,000 项符合查询结果（耗时：0.0533秒） [XML]
MySQL combine two columns into one column
...does not start with a digit, then the converted value is 0.
So try this:
select concat(column1, column2)
Two ways to add a space:
select concat(column1, ' ', column2)
select concat_ws(' ', column1, column2)
share
...
Is there a better way to dynamically build an SQL WHERE clause than by using 1=1 at its beginning?
... {2}", clause, appender, condition);
}
Use it like this
string query = "SELECT * FROM Table1 {0}";
string whereClause = string.Empty;
if (condition 1)
whereClause = AddCondition(whereClause, "AND", "Col=1");
if (condition 2)
whereClause = AddCondition(whereClause, "AND", "Col2=2");
str...
Android gradle: buildtoolsVersion vs compileSdkVersion
...n? I remember that I read somewhere that the latest build tools version is selected automatically. I tried removing buildToolsVersion, but Android Studio is not happy with it.
– Hong
Apr 25 '15 at 1:39
...
How to get the list of all printers in computer
...ement API to query them:
var printerQuery = new ManagementObjectSearcher("SELECT * from Win32_Printer");
foreach (var printer in printerQuery.Get())
{
var name = printer.GetPropertyValue("Name");
var status = printer.GetPropertyValue("Status");
var isDefault = printer.GetPropertyValue("...
What is size_t in C?
...array index.
Depending on the implementation, it can be any of:
unsigned char
unsigned short
unsigned int
unsigned long
unsigned long long
Here's how size_t is defined in stddef.h of my machine:
typedef unsigned long size_t;
...
Python SQL query string formatting
...qualified a somewhere between Option 2 and Option 4
Code Sample:
sql = ("SELECT field1, field2, field3, field4 "
"FROM table "
"WHERE condition1=1 "
"AND condition2=2;")
Works as well with f-strings:
fields = "field1, field2, field3, field4"
table = "table"
conditions = "co...
Filter dataframe rows if value in column is in a set list of values [duplicate]
...id 7
9 1980-01-10 9 Jones 4
There are multiple ways of selecting or slicing the data.
Using .isin
The most obvious is the .isin feature. You can create a mask that gives you a series of True/False statements, which can be applied to a dataframe like this:
mask = df['STK_ID'].isin...
Managing CSS Explosion
...he start of each line when writing TOCs, it just makes it more annoying to select the text.
/* Table of Contents
- - - - - - - - -
Header stuff
Body Stuff
Some other junk
- - - - - - - - -
*/
...
/* Header Stuff
*/
...
/* Body Stuff
*/
Write comments with or within the rules, ...
Git: How to rebase to a specific commit?
... X --- Y --- Z feature
To move the entire feature branch, you can not select X, Y, Z, or feature as the <Target> since those all are commits inside the group being moved.
<Upstream> is special because it can mean two different things. If it is a commit that is an ancestor of the ch...
Stop Excel from automatically converting certain text values to dates
...qualifier if you have surrounded your values by quotes
In the third page, select every column individually and assign each the type "Text" instead of "General" to stop Excel from messing with your data.
Hope this helps you or someone with a similar problem!
...