大约有 47,000 项符合查询结果（耗时：0.0563秒） [XML]
“where 1=1” statement [duplicate]
...
It's usually when folks build up SQL statements.
When you add and value = "Toyota" you don't have to worry about whether there is a condition before or just WHERE. The optimiser should ignore it
No magic, just practical
Example Code:
commandText = "select * from car_table where 1=1...
Why would someone use WHERE 1=1 AND in a SQL clause?
Why would someone use WHERE 1=1 AND <conditions> in a SQL clause (Either SQL obtained through concatenated strings, either view definition)
...
What's the difference between a single precision and double precision floating point operation?
What is the difference between a single precision floating point operation and double precision floating operation?
11 Answ...
What are JavaScript's builtin strings?
...
First of all, I would like to thank Jason and all the contributors for playing with that funny snippet. I have written that piece of code just for fun in order to send it to my wife on February 14 :) Having only Chrome installed on the laptop I had no options to chec...
What are bitwise operators?
I'm someone who writes code just for fun and haven't really delved into it in either an academic or professional setting, so stuff like these bitwise operators really escapes me.
...
Bitwise operation and usage
...ators that work on multi-bit values, but conceptually one bit at a time.
AND is 1 only if both of its inputs are 1, otherwise it's 0.
OR is 1 if one or both of its inputs are 1, otherwise it's 0.
XOR is 1 only if exactly one of its inputs are 1, otherwise it's 0.
NOT is 1 only if its input is 0, o...
Is there a better way to dynamically build an SQL WHERE clause than by using 1=1 at its beginning?
...l1=0");
//...
if (conditions.Any())
Query += " WHERE " + string.Join(" AND ", conditions.ToArray());
share
|
improve this answer
|
follow
|
...
Peak signal detection in realtime timeseries data
...n the principle of dispersion: if a new datapoint is a given x number of standard deviations away from some moving mean, the algorithm signals (also called z-score). The algorithm is very robust because it constructs a separate moving mean and deviation, such that signals do not corrupt the threshol...
How many double numbers are there between 0.0 and 1.0?
... 52-bit fraction; between any two adjacent powers of two (inclusive of one and exclusive of the next one), there will therefore be 2 to the 52th power different doubles (i.e., 4503599627370496 of them). For example, that's the number of distinct doubles between 0.5 included and 1.0 excluded, and ex...
What does ** (double star/asterisk) and * (star/asterisk) do for parameters?
In the following method definitions, what does the * and ** do for param2 ?
22 Answers
...