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author | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-10-11 12:34:02 -0400 |
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committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-10-11 12:34:02 -0400 |
commit | c94a4b2cea888903fdc9595917b10c4fa8b36afc (patch) | |
tree | cd006eb944b06c316f53799859afa07c02db54a4 | |
parent | bee9b92ea094115269ba18e5b85b5cfe23b7f79d (diff) | |
download | sqlalchemy-c94a4b2cea888903fdc9595917b10c4fa8b36afc.tar.gz |
Add missing changelog file for #7153
Fixes: #7153
Change-Id: I613d3179781344923add904cbdca87aff89eee83
-rw-r--r-- | doc/build/changelog/unreleased_14/7153.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/doc/build/changelog/unreleased_14/7153.rst b/doc/build/changelog/unreleased_14/7153.rst new file mode 100644 index 000000000..762fb638d --- /dev/null +++ b/doc/build/changelog/unreleased_14/7153.rst @@ -0,0 +1,25 @@ +.. change:: + :tags: bug, sql + :tickets: 7153 + + Adjusted the "column disambiguation" logic that's new in 1.4, where the + same expression repeated gets an "extra anonymous" label, so that the logic + more aggressively deduplicates those labels when the repeated element + is the same Python expression object each time, as occurs in cases like + when using "singleton" values like :func:`_sql.null`. This is based on + the observation that at least some databases (e.g. MySQL, but not SQLite) + will raise an error if the same label is repeated inside of a subquery. + +.. change:: + :tags: bug, orm + :tickets: 7154 + + Related to :ticket:`7153`, fixed an issue where result column lookups would + fail for "adapted" SELECT statements that selected for "constant" value + expressions most typically the NULL expression, as would occur in such + places as joined eager loading in conjunction with limit/offset. This was + overall a regression due to issue :ticket:`6259` which removed all + "adaption" for constants like NULL, "true", and "false" when rewriting + expressions in a SQL statement, but this broke the case where the same + adaption logic were used to resolve the constant to a labeled expression + for the purposes of result set targeting. |