Editing MySQL full text search equivalents to Google search (section)

==== Instruction of SQL syntax ====
(1) [https://www.w3resource.com/mysql/string-functions/mysql-position-function.php MySQL POSITION() function - w3resource] "MySQL POSITION() returns the position of a substring within a string."
<pre>
SET @term := "吸星大法";
SET @message := "笑傲江湖中嵩山派掌門左冷禪所創掌法，可發出至陰至寒的真氣。左冷禪與任我行比武時，以此功對付吸星大法，使其全身凍僵、天池穴被封;與岳不群比劍奪帥時，左又使出寒冰神掌，與紫霞神功旗鼓相當、不分勝敗。

原文網址：https://kknews.cc/zh-tw/culture/xzaxbq.html";
SELECT POSITION(@term IN @message)

-- > returns 46
</pre>

(2) Avoid the the start position is 0 or negative. Minimum start position of each paragraph is 1.
<pre>
SELECT IF(
            POSITION(@term IN @message) > 0 &&
            POSITION(@term IN @message) -10 < 0
            , 1
            , POSITION(@term IN @message) -10)

-- > returns 36 = 46 - 10
</pre>

(3) Show 10 characters before or after the search keywords. [https://www.w3resource.com/mysql/string-functions/mysql-substring-function.php MySQL SUBSTRING() function - w3resource]"returns a specified number of characters from a particular position of a given string."
<pre>

SELECT 
@message

, CASE
  WHEN POSITION(@term IN @message) > 0 THEN SUBSTRING(@message
        , IF(
            POSITION(@term IN @message) > 0 &&
            POSITION(@term IN @message) -10 < 0
            , 1
            , POSITION(@term IN @message) -10)
        , CHAR_LENGTH(@term) + 20
      )
  ELSE ''
END AS `scrapbook`;

-- > returns 行比武時，以此功對付吸星大法，使其全身凍僵、天池
</pre>

<pre>
SET @term := "吸星大法";
SET @message := "原文網址：https://kknews.cc/zh-tw/culture/xzaxbq.html";


SELECT 
@message

, CASE
  WHEN POSITION(@term IN @message) > 0 THEN SUBSTRING(@message
        , IF(
            POSITION(@term IN @message) > 0 &&
            POSITION(@term IN @message) -10 < 0
            , 1
            , POSITION(@term IN @message) -10)
        , CHAR_LENGTH(@term) + 20
      )
  ELSE ''
END AS `scrapbook`

-- Returned result of scrapbook column: Show 10 characters before or after the search keywords.
-- [EMPTY]
</pre>