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Mysql case else11/8/2023 ![]() | Jupyter | Moonbeam | 41 | MEX | Neighbor mid 40's |Ĭonsider making a small donation on my behalf as I continue to provide valuable content here on my blog. | Jim | Russ | 44 | USA | Not mid 40 's | | Roger | Dodger | 44 | USA | Not mid 40's | | Humpty | Dumpty | 48 | ITA | Neighbor mid 40 's | | Charlie | Charles | 48 | USA | Mid 40's | | Mary | Murphy | 41 | CAN | Not sure at this time | | Max | Maxer | 44 | USA | Not mid 40 's | | first_name | last_name | age | country | age_description | WHEN country = 'MEX' OR country = 'ITA' AND age > 45 THEN 'Neighbor mid 40' 's' WHEN country = 'USA' AND age 45 THEN 'Mid 40' 's' SELECT first_name, last_name, age, country , In this next query, notice the presence of the greater than (>) and less than (<) comparison operators in addition to the equality test on the ‘country’ column value: MySQL Searched CASE Expression: Multiple conditionals and comparisons Where the Simple CASE only permits an equality comparison, notice in the Searched CASE example, the presence of the AND logical operator, allowing multiple conditions to be evaluated. | country | state | country_state_description | WHEN country = 'MEX' AND state IS NULL THEN 'Unknown MEX state' WHEN country = 'CAN' AND state IS NULL THEN 'Unknown Canada State' The Searched CASE expression can be more complex than Simple CASE, having multiple different types of conditions in the WHEN clause:ĬASE WHEN country = 'USA' AND state = 'k' THEN 'Unknown US State' ![]() I would be remiss if I said these are the only ways you can use Searched CASE for its use goes far beyond what I can cover in this blog post. While the example queries that follow are arbitrary and likely not very meaningful, my goal is to provide a foundational understanding of how you might use a Searched CASE expression. ![]() The key difference is that Searched CASE allows multiple comparisons in any of the WHEN clauses. However, they are very far from being one and the same. Other than that, the structure is the same between the two. Syntax-wise, the MySQL searched CASE expression is similar to the Simple CASE with the exception that no column or expression is listed immediately following the CASE keyword as is with Simple CASE. | MEX | Jupyter | Moonbeam | NULL | 198 - 654 - 2827 | 1978 - 07 - 22 | 41 |ħ rows in set ( 0.0015 sec ) MySQL Searched CASE Expression: Syntax and similarities compared to the Simple CASE Expression | country | first_name | last_name | state | phone_num | birthday | age | Syntax CASE WHEN THEN result THEN result. In the absence of an else clause, the function will return NULL. Otherwise, the else clause will be returned. Example SELECT CASE 2 WHEN 2 THEN 'two' WHEN 1 THEN 'one' ELSE 'more' END įollowing the successful execution of the above command, we will see the following output.Īs a second method, a search condition is considered in the WHEN clauses, and if it is found, the result is returned in the corresponding THEN clause. ![]() When the first compare_value comparison is true, it returns the result. Syntax CASE value WHEN THEN result THEN result. The CASE statement can be used in two different ways: Simple CASE statement:Īs shown below, the first method involves matching a value with the given statement. In MySQL, the CASE statement is used to handle multiple IF statements within the SELECT clause. A NULL value is returned when the else block is not found. If no condition is found to be true, it executes the else block. Once the condition is met, the traversal is stopped and the output is displayed. When the first condition is true, the CASE expression returns the result. The expression can be used anywhere that uses a valid program or query, such as the SELECT, WHERE, ORDER BY clause, etc. The MySQL CASE expression is a part of the control flow function that allows us to write an if-else logic to a query.
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