MySQL删除列中n个单词后的所有内容

Question

I have a table with over 5000 entries, and basically I want to replace the texts with excerpts. So the column 'text' has between 1000 and 2000 words, most of the time. I want every cell to be cut after 80 words. Additionally it would be nice to add something like 'Read more...' after the 80 words. Is it possible with a MySQL Query?

Answer 1

This is bad idea to do that from MySQL level. This is about the VIEW Layer, so should be programmed in the place which read the data from the database and presents them. In PHP, it can be done with

function cutStringAfterWords($phrase,$max_words){
    $phrase_array = explode(' ',$phrase);
    if(count($phrase_array) > $max_words && $max_words > 0)
        $phrase = implode(' ',array_slice($phrase_array, 0, $max_words)).'...';
    return $phrase;
}

echo cutStringAfterWords($largeText,80).' Read more...';

, but I believe most of the languages have their equivalents.

Edit: made an example to cut after 80 words. you can simply replace 3 dots within function to place Read more always, or remove 3 dots in function, and manually add 'Read More...' string after every truncated text

Answer 2

You can try with regex.

select REGEXP_SUBSTR(your_column_name,'(.+?\\s+|.+?){1,80}')
from your_table_name

Answer 3

There's nice MySQL string function SUBSTRING_INDEX which you can use like this to get the result you want:

UPDATE your_table SET your_text_field = (SELECT SUBSTRING_INDEX(your_text_field, ' ', 80) FROM your_table WHERE text_id = some_id) WHERE text_id = some_id;

To add 'Read More..' you can use MySQL CONCAT .

Also, I would suggest backing up your table before you start experimenting.

Answer 4

execute below query to update all records with first 80 characters

update your_table_name set column_name=SUBSTRING_INDEX(column_name, ' ', 80)

Updated with SUBSTRING_INDEX since you need words