sql: clean up error messages in join checks

[knz]

Prior to this patch a join on two anonymous sources would fail
with an ugly message:

pq: table name "{"" "" %!s(bool=false)}" specified more than once

This was not caught previously because the tests had a wildcard
pattern on the generated table name in the error message. This patch
addresses this and a couple related error messages.

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This change is

[knz]

(found while answering #8566)

[RaduBerinde]

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Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, some commit checks pending.

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sql/table_join.go, line 472 [r1] (raw file):

      if _, ok := left.info.sourceAliases[alias]; ok {
          t := alias.Table()
          switch t {

this is just an if/else..

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Comments from Reviewable

[knz]

Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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sql/table_join.go, line 472 [r1] (raw file):

Previously, RaduBerinde wrote…

this is just an if/else..

True but I found the 4 braces of an if/else overwhelming to read. Do we have a style guideline here?

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Comments from Reviewable

[RaduBerinde]

Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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sql/table_join.go, line 472 [r1] (raw file):

Previously, knz (kena) wrote…

True but I found the 4 braces of an if/else overwhelming to read. Do we have a style guideline here?

Are you seriously going to start using `switch` instead of `if/else` because there are two extra braces? :)

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Comments from Reviewable

[knz]

Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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sql/table_join.go, line 472 [r1] (raw file):

Previously, RaduBerinde wrote…

Are you seriously going to start using switch instead of if/else because there are two extra braces? :)

When the payload (body) is large enough (in number of characters) in comparison, then yes... Do you see an objection?

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Comments from Reviewable

[RaduBerinde]

Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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sql/table_join.go, line 472 [r1] (raw file):

Previously, knz (kena) wrote…

When the payload (body) is large enough (in number of characters) in comparison, then yes...
Do you see an objection?

No objection, I just find it odd.

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Comments from Reviewable

[knz]

Review status: 0 of 3 files reviewed at latest revision, 1 unresolved discussion, some commit checks pending.

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sql/table_join.go, line 472 [r1] (raw file):

Previously, RaduBerinde wrote…

No objection, I just find it odd.

Ok I just changed it back.

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Comments from Reviewable