SQL Fiddle

Question

请帮帮我我有一列Delay_Reason，其中我有以下值。值可能以＆＃34 ;;＃＆＃34;结束。或者可能不是。

DT1-Increased_CT_Reason_Start_to_Accept

ERIC_Drive Test Taking too Long;#ERIC_Lack Of GSC Resources/Queuing  DT  Drives;#ERIC_Cluster Having Too Many RF Issues Needing Tuning;#
ERIC_Drive Test Taking too Long;#ERIC_Lack Of GSC Resources/Queuing DT Drives;# 
ERIC_Drive Test Taking too Long;#

我必须算一下delay_reason。

我想要的输出是

DT1-Increased_CT_Reason_Start_to_Accept                   count  

ERIC_Drive Test Taking too Long                            3  
ERIC_Lack Of GSC Resources/Queuing  DT Drives              2
ERIC_Cluster Having Too Many RF Issues Needing Tuning      1

Answer 1

您可以使用的一个技巧是将Delay_Reason列的长度与删除单个字母的同一列的长度进行比较。然后，在整个表格中总结这个差异以获得出现次数。

SELECT 'a' AS Delay_Reason,
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason, 'a', ''))) count
FROM yourTable
UNION ALL
SELECT 'b',
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason, 'b', '')))
FROM yourTable
UNION ALL
SELECT 'c',
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason, 'c', '')))
FROM yourTable

在这里演示：

SQL Fiddle

<强>更新

如果您想使上述查询适用于长于单个字符的术语，您只需要使用搜索词的长度进行规范化：

SELECT 'Los NE abc' AS Delay_Reason,
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason,'Los NE abc','')))
           / CHAR_LENGTH('Los NE abc') AS count
FROM yourTable
UNION ALL
SELECT 'Angeles',
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason,'Angeles','')))
           / CHAR_LENGTH('Angeles')
FROM yourTable
UNION ALL
SELECT 'California',
       SUM(CHAR_LENGTH(Delay_Reason) - CHAR_LENGTH(REPLACE(Delay_Reason,'California','')))
           / CHAR_LENGTH('California')
FROM yourTable

以下是此查询的演示：

SQLFiddle

Answer 2

SELECT Delay_Reason,COUNT(*)
FROM test      
GROUP BY Delay_Reason;

Answer 3

问题是数据库在一个字段中存储多个值。当前架构违反了第3范式。

一种解决方案是运行查询以规范化您的数据，然后对该查询运行常规聚合查询。 substring_index可用于此目的。

SQL Fiddle

CREATE TABLE yourTable (`Delay_Reason` varchar(512));

INSERT INTO yourTable (`Delay_Reason`)
VALUES
    ('ERIC_Drive Test Taking too Long;#ERIC_Lack Of GSC Resources/Queuing DT Drives;#ERIC_Cluster Having Too Many RF Issues Needing Tuning;#'),
    ('ERIC_Drive Test Taking too Long;#ERIC_Lack Of GSC Resources/Queuing DT Drives;# '),
    ('ERIC_Drive Test Taking too Long;#') ;


select delay_reason, count(*) count from (
    /* 
        normalise the data
        add as many substring_index union all elements as required
        */
    select SUBSTRING_INDEX(delay_reason, ';#', 1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 2), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 3), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 4), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 5), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 6), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 7), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 8), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 9), ';#', -1) AS delay_reason from yourTable
    union all
    select SUBSTRING_INDEX(SUBSTRING_INDEX(delay_reason, ';#', 10), ';#', -1) AS delay_reason from yourTable
) delay_reasons
/* remove empty values */
where delay_reason <> ''
group by delay_reason
order by count desc;

- 示例结果

delay_reason count

ERIC_Drive测试耗时过长3

ERIC_Lack GSC资源/排队DT驱动器2

ERIC_Cluster需要太多RF问题需要调优1

如果您有权更改架构，您还可以规范化数据。 Search Google for third normal form explained

要求mysql中的字段数

3 个答案:

SQL Fiddle

SQLFiddle