copy and paste this google map to your website or blog!
Press copy button and paste into your blog or website.
(Please switch to 'HTML' mode when posting into your blog. Examples: WordPress Example, Blogger Example)
Input Form:Deal with this potential dealer,buyer,seller,supplier,manufacturer,exporter,importer
(Any information to deal,buy, sell, quote for products or service)
c# - What does null! statement mean? - Stack Overflow It can be used on a type to control Nullability, it is then called the "Null Forgiving Operator" Basically, null! applies the ! operator to the value null This overrides the nullability of the value null to non-nullable, telling the compiler that null is a "non-null" type
SQL is null and = null - Stack Overflow The reasoning is that a null means "unknown", so the result of any comparison to a null is also "unknown" So you'll get no hit on rows by coding where my_column = null SQL provides the special syntax for testing if a column is null, via is null and is not null, which is a special condition to test for a null (or not a null)
What is the difference between is not null and != null? The only difference (besides the syntax) is, that the compiler guarantees that no user-overloaded operator is called when using is not null instead of != null (or is null instead of == null) From operator overloading: A user-defined type can overload a predefined C# operator That is, a type can provide the custom implementation of an operation in case one or both of the operands are of that
Why does NULL = NULL evaluate to false in SQL server The expression "NULL = NULL" evaluates to NULL, but is actually invalid in SQL; yet ORDER BY treats NULLs as equal (whatever they precede or follow "regular" values is left to DBMS vendor)
What is the difference between NULL, \0 and 0? - Stack Overflow In C, there appear to be differences between various values of zero -- NULL, NUL and 0 I know that the ASCII character '0' evaluates to 48 or 0x30 The NULL pointer is usually defined as: #define
sql - Not equal lt; gt; != operator on NULL - Stack Overflow 135 NULL has no value, and so cannot be compared using the scalar value operators In other words, no value can ever be equal to (or not equal to) NULL because NULL has no value Hence, SQL has special IS NULL and IS NOT NULL predicates for dealing with NULL
How do I check for null values in JavaScript? - Stack Overflow And then == null does a perfect job, because it covers exactly those 2 values (i e == null is equivalent to === null === undefined) In exceptional cases you do want a clear distinction between null and undefined
Best way to check for null values in Java? - Stack Overflow The null check will be at least a thousand times faster (probably many thousands) For the path of execution to get into the catch block an exception has to have been raised which means generating a stack trace etc etc I don't know for sure but the null check almost certainly drops to a native instruction so it's as close to instant as you can
What are the differences between Null, Zero and Blank in SQL? Comparing NULL with anything yields a NULL NULL is part of trinary logic: TRUE, FALSE, and NULL -- These are all NULL select NULL > -1, NULL < -1, NULL = NULL, NULL = 0; Blank is ill-defined It means different things in different contexts to different people For example: AFAIK, there is no SQL or MySQL specific technical meaning for "blank"