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2 Ιουλ 2010 · Based on my condition, (for eg. length), I want to execute different SQL statement. Problematic sample query is as follows: select case. when char_length('19480821') = 8. then select count(1) from Patient. when char_length('19480821')=10. then select count(1) from Doctor. end.
The CASE expression provides conditional SQL expressions. You can use case expressions anywhere you can use an expression. The syntax of the CASE expression is as follows: CASE expression . WHEN expression THEN expression [, …] [ ELSE expression ] END. You cannot use a subquery as a value expression in a CASE statement.
7 Δεκ 2023 · How to use CASE for IF-THEN logic in SQL SELECT. If you want to see the grade for each exam, select the case expression like a regular column: It’s a good idea to give the expression an alias. This is particularly important if the case is in a subquery.
7 Μαΐ 2017 · As you write an SQL query, you may need to get values from multiple columns and change values from one form to another. The simple way to achieve this goal is to add a CASE expression to your SELECT statement. In this article, we'll introduce you to the syntax, formats, and uses of the CASE expression.
Oracle CASE expression allows you to add if-else logic to SQL statements without having to call a procedure. The CASE expression evaluates a list of conditions and returns one of the multiple possible results. You can use a CASE expression in any statement or clause that accepts a valid expression.
The CASE expression goes through conditions and returns a value when the first condition is met (like an if-then-else statement). So, once a condition is true, it will stop reading and return the result. If no conditions are true, it returns the value in the ELSE clause.
CASE expressions let you use IF... THEN... ELSE logic in SQL statements without having to invoke procedures. The syntax is:
