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Apr 6, 2009 · 46. Yes; Microsoft themselves recommend using <> over != specifically for ANSI compliance, e.g. in Microsoft Press training kit for 70-461 exam, "Querying Microsoft SQL Server", they say "As an example of when to choose the standard form, T-SQL supports two “not equal to” operators: <> and !=. The former is standard and the latter is not.
Feb 18, 2015 · AND has precedence over OR in every language I know. So, the 2 expressions are simply not equal. WHERE some_col in (1,2,3,4,5) AND some_other_expr --to the optimiser is this WHERE ( some_col = 1 OR some_col = 2 OR some_col = 3 OR some_col = 4 OR some_col = 5 ) AND some_other_expr. So, when you break the IN clause up, you split the serial ORs up ...
Apr 14, 2011 · In SQL, anything you evaluate / compute with NULL results into UNKNOWN. This is why SELECT * FROM MyTable WHERE MyColumn != NULL or SELECT * FROM MyTable WHERE MyColumn <> NULL gives you 0 results. To provide a check for NULL values, isNull function is provided. Moreover, you can use the IS operator as you used in the third query.
First query will provide the required output i.e. select those records for which colName is having a null value. But the second query will result in zero matching records. Please clarify different uses of these operators with pros and cons. EDIT. Here, most of the answers are claiming that = doesn't work with null, but the following statement ...
Mar 2, 2013 · When you use <>, I believe the engine scans/seeks all values that are greater than or less than. When we use !=, it simply goes for all values that don't equal what you defined. We've seen performance gains from 30 mins to 3 mins on several of our procedures here. Again, everyone's environments/indexes are different, but we try to avoid using ...
Feb 21, 2014 · 21. <=> is MySQL's null-safe "equal to" operator. From the manual: NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operands are NULL, and 0 rather than NULL if one operand is NULL. mysql> SELECT 1 <=> 1, NULL <=> NULL, 1 <=> NULL; -> 1, 1, 0.
Jul 23, 2012 · How to make a query with AND and OR operators? 2. SQL Query: Using AND/OR in the WHERE clause. 0. Syntax ...
2. The !=, !< and !> are not standard comparison operators and are only supported by few systems, SQL-Server being one: msdn: Comparison Operators (Transact-SQL). MySQL also supports != but only that, not the other two. The equivalent standard SQL comparison operators are <>, >= and <=. In all situations, I would prefer the standard.
Sep 7, 2009 · Oracle 10g has functions that allow the use of POSIX-compliant regular expressions in SQL: REGEXP_LIKE; REGEXP_REPLACE; REGEXP_INSTR; REGEXP_SUBSTR; See the Oracle Database SQL Reference for syntax details on this functions. Take a look at Regular expressions in Perl with examples. Code : select * from tbl where regexp_like(col, '^(ABC|XYZ|PQR)');
Feb 13, 2009 · Different Operators. LIKE and = are different operators. Most answers here focus on the wildcard support, which is not the only difference between these operators! = is a comparison operator that operates on numbers and strings. When comparing strings, the comparison operator compares whole strings. LIKE is a string operator that compares ...
