Fix typos in placement-rules-in-sql.md

[dcswinner01]

fix typo.

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modify alter database grammer

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[TomShawn]

/remove-status LGT1
/status LGT2

[TomShawn]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 7807062

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #8976.