Conditional statements are very prevalent when working with databases. For example, we can use the CASE keyword in SQL to provide a set of evaluated conditions. We can then execute the code block if a given statement is true. A case statement is similar to a nested if…else block which al...
Any data type can be used in the WHEN condition, as long as the result is either true or false. The expressions in the THEN or ELSE argument can also be of other data types than just strings. For example, we can return numbers as well. In this example, we’ll update the vacation h...
SELECTcolumn1, column2, ...CASEWHENcondition1THENresult1WHENcondition2THENresult2-- Add more WHEN conditions and results as neededENDASalias_nameFROMtable_name; We can add as manyWHEN ... THENconditions as required in theCASEstatement. For example, -- multiple CASE conditions in SQLSELECTcusto...
PostgreSQL CASE WHEN: Conditional Logic in Queries< The CASE WHEN expression in PostgreSQL provides conditional logic within SQL queries. This guide covers syntax, usage examples, and practical applications. What is CASE WHEN in PostgreSQL? The CASE WHEN expression is used to implement conditional log...
其实Pandas也可以实现的，比如万能的apply方法，就是写起来复杂一些，没有sql case when那么直观。
Application of Case-when in MySQL LIU Lei1,LIN Li-dan 2 (1.He nan Police College,Zhengzhou 450000, China;2.Luo he Vocational Technology College, Luohe 462000, China) Abstract: In the actual research and development work, it is often necessary to write all kinds of SQL to statistic all ...
Practical Example To better demonstrate how we can work with the SQL COUNT CASE WHEN statement, let us use a real-world database such as the Sakila database. Problem: Our goal is to determine the number of rentals that are made by each customer in the rental table of the Sakila databas...
Simple SQL CASE Example Here is the syntax for the SQLCASEexpression: CASE WHENcondition_1THENresult_1 WHENcondition_2THENresult_2 ELSEelse_result END In this syntax, SQLCASEmatches the value with eithercondition_1orcondition_2. If a match is found, the statement will return the corresponding...
case when in sql server's stored procedure Evaluates a list of conditions and returns one of multiple possible result expressions. The CASE expression hastwo formats: The simple CASE expression compares an expression to a set of simple expressions to determine the result....
ExampleGet your own SQL Server SELECT OrderID, Quantity,CASE WHEN Quantity > 30 THEN 'The quantity is greater than 30' WHEN Quantity = 30 THEN 'The quantity is 30' ELSE 'The quantity is under 30'END AS QuantityTextFROM OrderDetails; Try it Yourself » ...