Changed paths:
M django/db/backends/mysql/client.py
M django/db/backends/oracle/client.py
M django/db/backends/postgresql_psycopg2/client.py
M django/db/backends/sqlite3/client.py
Log Message:
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Fixed #22234 -- Replaced OS-specific code with subprocess.call() in dbshell.
This fixes escaping of special characters on Windows.