'How defer script is different that preload link?

Preload: fetch a CSS stylesheet and apply it at some later time, fetch a JavaScript asset and execute it later, and so on. Preload fetches do not block the document load event and allow the application to determine which resources are applied, when they are executed, and in which order.

Defer: The "defer" preloads during HTML parsing and will only execute it after the parser has completed.

I cant understand the differences in both concepts. Both fetch stuff asynchronously without blocking the parser and afterwards both can be executed when the parser is done.

So is there any difference at all?

javascripthtmlcssdeferredpreloadmysqlsqlmysql-workbench


Solution 1:[1]

Preload fetches do not block the document load event and allow the application to determine which resources are applied, when they are executed, and in which order. Defer: The "defer" preloads during HTML parsing and will only execute it after the parser has completed.

Solution 2:[2]

Use a self join and aggregation:

SELECT a1.Author_name AuthorA, 
       a2.Author_name AuthorB,
       COUNT(*) JointPapers
FROM Authors a1 INNER JOIN Authors a2
ON a1.Paper_ID = a2.Paper_ID AND a1.Author_ID < a2.Author_ID
GROUP BY a1.Author_name, a2.Author_name;

Or, if there is a case that 2 authors may have the same name:

SELECT a1.Author_ID IDA, a1.Author_name AuthorA, 
       a2.Author_ID IDB, a2.Author_name AuthorB,
       COUNT(*) JointPapers
FROM Authors a1 INNER JOIN Authors a2
ON a1.Paper_ID = a2.Paper_ID AND a1.Author_ID < a2.Author_ID
GROUP BY a1.Author_ID, a1.Author_name, a2.Author_ID, a2.Author_name;

See the demo.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 Bottle Of Soul
Solution 2

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