Connect to a Database: Use the psql command followed by the -U flag to specify the username and the -d flag to specify the database name. This command connects you to the PostgreSQL database.

# Connect to a Database

    username = “your_username”

    database_name = “your_database”

    connect_command = f”psql -U {username} -d {database_name}”

    subprocess.run(connect_command, shell=True)

List Databases: After connecting to psql, use the \l command to list all the databases available in the PostgreSQL server.

    # List Databases

    subprocess.run(“psql -l”, shell=True)

Connect to a Database (without Password Prompt): Similar to connecting to a database, but add the -W flag to prompt for the password interactively rather than in the URL.

   # Connect to a Database (without Password Prompt)

    connect_without_prompt_command = f”psql -U {username} -d {database_name} -W”

    subprocess.run(connect_without_prompt_command, shell=True)

List Tables: After connecting to a specific database, use the \dt command to list all the tables in that database.

# List Tables

                    subprocess.run(“psql -c ‘\\dt'”, shell=True)

Describe a Table: Use the \d command followed by the table name to get information about the specified table, including its columns, types, and constraints.

# Describe a Table

    table_name = “your_table”

    describe_command = f”psql -c ‘\\d {table_name}'”

    subprocess.run(describe_command, shell=True

Execute SQL File: Use the \i command followed by the path to the SQL file to execute SQL commands stored in a file.

 # Execute SQL File

    sql_file_path = “path/to/sql_file.sql”

    execute_file_command = f”psql -U {username} -d {database_name} -f {sql_file_path}”

    subprocess.run(execute_file_command, shell=True)

Execute a Single SQL Command: Use the \c command followed by the SQL command you want to execute. This is useful for quick operations without creating a separate SQL file.

# Execute a Single SQL Command

    sql_command = “SELECT * FROM your_table;”

    execute_command_command = f”psql -c ‘{sql_command}'”

    subprocess.run(execute_command_command, shell=True)

Exit psql: Use the \q command to quit the psql shell and return to the command line.

  # Exit psql

    print(“Exiting psql…”)

Run SQL Script with Echo: Use the -a flag along with the -f flag followed by the path to the SQL script to run a SQL script file with echoed commands, showing each command before executing it.

# Run SQL Script with Echo

    sql_script_path = “path/to/sql_script.sql”

    execute_script_echo_command = f”psql -U {username} -d {database_name} -a -f {sql_script_path}”

    subprocess.run(execute_script_echo_command, shell=True)

Display Query Results in Aligned Format: Use the \a command to toggle the output format to align. This makes query results easier to read.
       

         
# Display Query Results in Aligned Format

                subprocess.run(“psql -c ‘\\a'”, shell=True)

Display Query Results in Expanded Format: Use the \x command to toggle the output format to expand. This is helpful for displaying wide rows more clearly.

# Display Query Results in Expanded Format

                            subprocess.run(“psql -c ‘\\x'”, shell=True)

Run psql in Quiet Mode: Use the -q flag when starting psql to run it in quiet mode, which only displays query results without any informational messages. This is useful for automation or scripting purposes.

# Run psql in Quiet Mode

    subprocess.run(“psql -q”, shell=True)

 if __name__ == “__main__”:

            main()