mysql存储过程问题: insert首先运行，无论我输入的条件是什么

INSERT INTO table_name (column1, column2, ...)
VALUES (value1, value2, ...);

CREATE PROCEDURE insert_data(condition VARCHAR(255))
BEGIN
    DECLARE data_value INT;
    
    -- 根据条件生成要插入的数据
    IF condition = 'A' THEN
        SET data_value = 1;
    ELSEIF condition = 'B' THEN
        SET data_value = 2;
    ELSE
        SET data_value = 3;
    END IF;
    
    -- 执行insert语句插入数据
    INSERT INTO table_name (column1) VALUES (data_value);
END;