The CASE statement in the WHERE clause can conditionally filter rows based on defined criteria. The syntax for the CASE statement in the WHERE clause is shown below. The CASE expression matches the condition and returns the value of the first THEN clause. If none of the conditions are true, ...
FYI, there is no guarantee that WHERE <filter 1> OR <filter 2> will be optimized so that the filters are evaluated in the order typed. SQL isn't that kind of language. Your best shot at getting the order as desired is with CASE: select ... where 1 = CASE WHEN <filter 1> THEN ...
CASE statement in SQL returns Null CASE statement in WHERE clause for IS NULL: I want to say IS or IS NOT Null for a column using CASE Case Statement in Where clause with parameters SQL Server CASE statement inclusion and exclusions case statement inside a where clause with 'IN' operator ...
8.优化select语句,这方面技巧同样适用于其他带where的delete语句等,在where子句的列上设置索引;索引对于引...
How to use CASE in the WHERE clause If you want to find all the exam results with A or B grades, you can place theselectabove in a subquery. Then filter it in the outer query. Or you can slap thecaseexpression directly in thewhereclause, like so: ...
use an index to identify rows to be updated, so a table scan is likely to occur with every ...
SQL DeleteSQL Where can use "case when" in where clause SQL Order By can use "case when" in order by clause SQL Group BySQL AND & ORSQL LikeSQL COUNT distinctSQL InSQL BetweenSQL AliasesSQL Not NullSQL(ES) DateSQL avg()SQL count()SQL last()...
Before closing the case expression with end, the optional else clause can be used. The <result> of else is used if no <condition> is true.1 If else is omitted, else null is implicit.2 The SQL standard does not specify how to process case expressions—it just defines the result.3 In...
This example uses the WHERE clause to define multiple conditions, but instead of using the AND condition, it uses the OR condition. In this case, this SQL statement would return all records from the products table where the product_name is either Pear or Apple.Example...
Let us take for example a case where we want to navigate the hierarchical organization or to represent a tree-like structure. We can use the WITH RECURSIVE keyword to create a recursive CTE. Since there is no hierarchical data that we can use in the Sakila database to demonstrate a recursi...