This question already has answers here:
Should I use != or <> for not equal in T-SQL?
(14 answers)
Closed 8 years ago.
I just wanted to know if there is a difference between <> and != when expressing inequality in SQL queries.
Technically these both function are the same, so you may choose whichever you find more readable.
The duplicate question has a relevant line:
'<>' is from the SQL-92 standard, '!=' is a proprietary T-SQL
operator.
Also to note that there are may database which doesnot != but since you have tagged it as SQL Server then there is no differenc between them
Related
This question already has answers here:
What is the meaning of <> in mysql query?
(7 answers)
Closed 3 years ago.
I know this is a really beginner question, but I don't know what the meaning of this. I'm reading the existing system code. I don't know what does this symbol means <> in Query Builder.
Here is the sample code:
$builder = DB::table('product');
if (isset($product->type)) {
$builder->where('product.type', '<>', $product->type);
}
Thanks!
In MySQL syntax, this is the same as not equal or !=.
This question already has an answer here:
SQL Fuzzy Matching
(1 answer)
Closed 6 years ago.
attempting to match a list of names that are similar in one very long column to another that are close but often vary do to missing letters and punctuation? is there a simple solution via a macro and/or sql?
using Levenstein functions can help
check the function and algorithm here: Levenshtein distance in T-SQL
after you create a function - compare the distance, for example:
select ..... from....
where dbo.Levenstein(str1,str2)>0.9 --means, the match between str1 and str2 is 90%
This question already has answers here:
CASE vs. DECODE
(7 answers)
Closed 6 years ago.
For some simple logical tests the same functionality can be achieved with CASE WHEN and DECODE syntax. What approach is better here (argumentation/measurement needed)?
SUM(CASE WHEN xyz=100 THEN 1 ELSE 0 END)
or
SUM(DECODE(xyz,100,1,0))
Recently I stumbled upon this: https://community.oracle.com/thread/1112467?tstart=0
"The performance difference is so slight that it makes very little sense in using that as primary criteria for whether to use CASE or DECODE. So unless you're calling this statement from a very tight loop doing millions of iterations, the decision should rather be which one, CASE or DECODE, best suits the need."
This question already has answers here:
What is the difference between <> and != operators in MySQL? [duplicate]
(4 answers)
Closed 7 years ago.
Why are there two negation operators in SQL language? != and <>.
Are they redundant or is there a difference between them depending on operands ?
Which one should I use to negate strings in MySQL ?
<> is ISO Sql Standard
!= is vendor specific
They both have no difference among them. It is just a personal preference which one to use. I always prefer <> since it is a ISO SQL standard
The SQL standard only specifies <> for not equals. SQL:2011 Foundation, section 5.2 <token> and <separator> specifies:
<not equals operator> ::=
<>
However some SQL implementations (like MySQL) also support != as a lot of programmers are more familiar with != for not equals. They are fully equivalent, so you can use either, but from a standards point of view you should use <>.
See also the MySQL documentation for not equals.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Split Function equivalent in tsql?
I have a column that contains data in the form:
CustomerZip::12345||AccountId::1111111||s_Is_Advertiser::True||ManagedBy::3000||CustomerID::5555555||
Does SQL have any sort of built in function to easily parse out this data, or will I have to build my own complicated mess of patindex/substring functions to pull each value into its own field?
I don't believe there is anything built in. Look at the comments posted against your original question.
If this is something you're going to need on a regular basis, consider writing a view.