MYSQL枢转行并受特定列的行限制

Question

不确定如何措辞这个问题，所以我给了我最好的表演，希望我的解释会帮助您理解。 如有任何疑问，请询问。

我的数据库具有以下设置：

create table spooner_pec
(
  id int,
  year varchar(20),
  policy_number int,
  primary_name varchar(200),
  experience_rate decimal(10,2),
  mco_name varchar(200)
);

插入以下值：

insert into spooner_pec values
(1,'2009',183586,'ZBIN LANDSCAPING INC', 1.22, 'GENEX CARE FOR OHIO'),
(1,'2011',183586,'ZBIN LANDSCAPING INC', 0.93, 'COMPMANAGEMENT HEALTH SYSTEMS, INC.'),
(1,'2012',183586,'ZBIN LANDSCAPING INC', 0.92, 'HEALTH MANAGEMENT SOLUTIONS, INC.'),
(1,'2013',183586,'ZBIN LANDSCAPING INC', 0.50, 'CAREWORKS'),
(1,'2014',183586,'ZBIN LANDSCAPING INC', 0.47, 'UNIVERSITY HOSPITALS COMPCARE'),
(1,'2010',183586,'ZBIN LANDSCAPING INC', 1.27, 'SHEAKLEY UNICOMP')

到目前为止，我一直在工作的查询是这样的：

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'max(case when year = ',
      year,
      ' then experience_rate end) AS `',
      year, '-Pen`'
    ) ORDER BY year
  ) INTO @sql
FROM
  spooner_pec;
SET @sql = CONCAT('SELECT policy_number, primary_name, ', @sql, ' 
                  FROM spooner_pec 
                   GROUP BY policy_number');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

因此，每个公司都有一行，然后每年都有一个年笔栏。 例如，我现在只需要获取最近一年的罚款大于1的行。 因此，如果输入所有数据的最后一年是2014年，那么我需要在这种情况下2014年笔> 1。

SQLFiddle

Answer 1

再次查询以获得最后一年，然后将其合并到SQL中。

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'max(case when year = ',
      year,
      ' then experience_rate end) AS `',
      year, '-Pen`'
    ) ORDER BY year
  ) INTO @sql
FROM
  spooner_pec;
SELECT MAX(year) INTO @lastYear FROM spooner_pec;
SET @sql = CONCAT('SELECT policy_number, primary_name, ', @sql, ' 
                  FROM spooner_pec 
                   GROUP BY policy_number
                   HAVING `', @lastYear, '-Pen` > 1');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;