Update cheatsheets

psql

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+---
+syntax: markdown
+tags: [tldr, common]
+source: https://github.com/tldr-pages/tldr.git
+---
+# psql
+
+> PostgreSQL command-line client.
+> More information: <https://www.postgresql.org/docs/current/app-psql.html>.
+
+- Connect to the database. By default, it connects to the local socket using port 5432 with the currently logged in user:
+
+`psql {{database}}`
+
+- Connect to the database on given server host running on given port with given username, without a password prompt:
+
+`psql -h {{host}} -p {{port}} -U {{username}} {{database}}`
+
+- Connect to the database; user will be prompted for password:
+
+`psql -h {{host}} -p {{port}} -U {{username}} -W {{database}}`
+
+- Execute a single SQL query or PostgreSQL command on the given database (useful in shell scripts):
+
+`psql -c '{{query}}' {{database}}`
+
+- Execute commands from a file on the given database:
+
+`psql {{database}} -f {{file.sql}}`