case語句

Question

我有這個存儲過程，其工作

CREATE PROCEDURE myrange() 
BEGIN 
SET @start = 0; 
PREPARE stmt FROM ' SELECT firstname FROM peoples ORDER BY id LIMIT ?,1 INTO @name'; 
    WHILE @start < 5 DO 
     EXECUTE stmt USING @start; 
     CASE 
      WHEN @name = 'Ana' 
       THEN INSERT INTO mytable (log) VALUES('yes'); 
      ELSE 
       INSERT INTO mytable (log) VALUES('no'); 
     END CASE; 
     SET @start = @start + 1; 
    END WHILE; 
END; 

，但是，如果我從這個程序刪除，這段代碼：

ELSE 
    INSERT INTO mytable (log) VALUES('no'); 

mysqli_error（）返回此錯誤：「CASE語句未找到案例」。

有人知道，爲什麼？

Answer 1

從MySQL CASE syntax

If no when_value or search_condition matches the value tested and the CASE statement contains no ELSE clause, a Case not found for CASE statement error results.

您必須覆蓋所有選項。

MySQL手冊是偉大的文檔。一定要訪問它！