First, you need to connect to your MySQL server using the command-line interface or a MySQL client.

   ```

   mysql -u username -p

   ```

Enter your password when prompted.

Choose the database you want to export data from.

   ```

   USE your_database_name;

   ```

Write the SQL query to select the data you want to export. For example:

   ```

   SELECT * FROM your_table_name;

   ```

Use the MySQL `INTO OUTFILE` clause to export the query results directly to a CSV file:

   ```

   SELECT * FROM your_table_name

   INTO OUTFILE '/path/to/output_file.csv'

   FIELDS TERMINATED BY ','

   ENCLOSED BY '"'

   LINES TERMINATED BY '\n';

   ```

Note: Make sure the MySQL server has write permissions to the specified output directory.

If you want to include column headers in your CSV, you can use a UNION query:

   ```

   (SELECT 'column1', 'column2', 'column3')

   UNION

   (SELECT column1, column2, column3 FROM your_table_name)

   INTO OUTFILE '/path/to/output_file.csv'

   FIELDS TERMINATED BY ','

   ENCLOSED BY '"'

   LINES TERMINATED BY '\n';

   ```

‍

If your data contains special characters or line breaks, you may need to adjust the FIELDS and LINES clauses:

   ```

   SELECT * FROM your_table_name

   INTO OUTFILE '/path/to/output_file.csv'

   FIELDS TERMINATED BY ','

   OPTIONALLY ENCLOSED BY '"'

   ESCAPED BY '\\'

   LINES TERMINATED BY '\r\n';

   ```

Alternatively, you can export data directly from the command line without entering the MySQL prompt:

   ```

   mysql -u username -p -e "SELECT * FROM your_database.your_table" -B | sed "s/'/\'/;s/\t/\",\"/g;s/^/\"/;s/$/\"/;s/\n//g" > output_file.csv

   ```

Once the export is complete, verify that the CSV file has been created and contains the expected data.

For very large datasets, you may need to split the export into multiple files or use the `mysqldump` utility:

   ```

   mysqldump -u username -p --tab=/path/to/output_directory your_database your_table

   ```

   This will create a .sql file with the table structure and a .txt file with the data.

Depending on your needs, you may want to perform some post-processing on the CSV file, such as removing unnecessary quotes or adjusting date formats.

Remember to always be cautious when exporting sensitive data and ensure you have the necessary permissions to read from the database and write to the output directory.

This process allows you to export MySQL data to CSV without relying on third-party tools, using only built-in MySQL and command-line utilities.