[CDS/CXL] Edit CXL guide

[renejeglinsky]

You can ignore the changes to the databases guides. They should not have been in this PR/branch.

[renejeglinsky]

The cds repl - sql log pattern is only used once. Is it an inconsistency or on purpose?

[renejeglinsky]

Overall cds repl is only used twice in a codeblock. In all other cases it's CQL. Why is that?

[patricebender]

The cds repl - sql log pattern is only used once. Is it an inconsistency or on purpose?

sql log was on purpose in this case, as the code contains more than just an SQL statement but multiple lines of one transaction. But IMO we could also just use SQL to be in line with the rest of the code groups. wdyt @Akatuoro ?

Overall cds repl is only used twice in a codeblock. In all other cases it's CQL. Why is that?

it should always be CQL :)

[Akatuoro]

Suggested change

	## ref — Element References & Path Expressions { #ref }
	## ref - Path Expressions { #ref }

Currently it's cut off and uses a different hyphen:

[Akatuoro]

The cds repl - sql log pattern is only used once. Is it an inconsistency or on purpose?

sql log was on purpose in this case, as the code contains more than just an SQL statement but multiple lines of one transaction. But IMO we could also just use SQL to be in line with the rest of the code groups. wdyt @Akatuoro ?

We can also use SQL here. The retrieval is different, but in the end it is SQL.

Overall cds repl is only used twice in a codeblock. In all other cases it's CQL. Why is that?

it should always be CQL :)

cds repl is always used when we do not focus on the actual CQL.

The first time, we use the Node.js fluent style CQL API (as compared to CQL or the CAP Java fluent style CQL API). This imho always gets confusing when we talk about "CQL", but sometimes we mean the actual language, other times we mean a fluent style API - they may support different things in different ways...... Here we explicitly use the Node.js CQL API because the actual CQL does not support INSERT.

The second time, we run cds.parse.expr which is not CQL.