This gem provides an easy way to convert SQL database queries to CSV. Below you can find the details of running this library.

• Installation
• Usage
  • Generating a Result object
  • Convert result data to CSV
  • Write result to CSV file
  • Get columns / headers
  • Get rows
• Batch Processing
  • Creating a Batch Manager
  • Processing Batches
  • Streaming to CSV
  • Tracking Progress
• ActiveRecord Integration
• Compatibility
• Todo
• Contributing
• License

Add this line to your application's Gemfile:

gem 'sqlreport'

And then execute:

$ bundle

Or install it yourself as:

$ gem install sqlreport

This library will connect your primary database connection. You can enter a query and get a result. With this result you can get the headers, columns and convert the results to a CSV

To generate a new result call this following method:

Sqlreport.query("SELECT * FROM test_table").result

Response

  <Sqlreport::Result:0x000000011f4db730>

To convert data to CSV just run the following command:

result = Sqlreport.query("SELECT * FROM test_table").result
result.to_csv(include_headers: true, separator: ",", quote_char: '"')

Response

  "id, name, other columns\t1,First name,other columns\t..."

To write the CSV data to a file just run the following command:

result = Sqlreport.query("SELECT * FROM test_table").result
result.write_csv("test_table.csv")

Response

  true

To rertieve the column names use the following commands:

result = Sqlreport.query("SELECT * FROM test_table").result
result.columns

Response

  ['id', 'name', 'other columns']

To rertieve the row data without the headers use the following commands:

result = Sqlreport.query("SELECT * FROM test_table").result
result.rows

Response

  [[1, "First name", "Other columns"], [2, "Second name", "Other columns"]]

This gem is tested with the following Ruby versions on Linux and Mac OS X:

• Ruby > 2.2.2

For handling large datasets, SQLreport provides batch processing capabilities that allow you to process data in chunks to avoid memory issues.

batch_manager = Sqlreport.batch_query("SELECT * FROM large_table", batch_size: 1000)

You can process one batch at a time:

# Get the next batch
batch = batch_manager.next_batch
# Process the batch
batch.rows.each do |row|
  # Process each row
end

Or process all batches at once with a block:

batch_manager.process_all do |batch|
  # Process each batch
  puts "Processing batch with #{batch.rows.count} rows"
end

For very large datasets, you can stream directly to a CSV file without loading all data into memory:

batch_manager.stream_to_csv("large_table.csv")

You can track the progress of batch processing:

batch_manager.count_total_rows # Get total row count for progress calculation
batch_manager.next_batch
puts "Processed #{batch_manager.processed_rows} of #{batch_manager.total_rows} rows"
puts "Progress: #{batch_manager.progress_percentage}%"

SQLreport can be used directly with ActiveRecord models and relations, allowing for a more fluent interface:

# Generate a report from an ActiveRecord relation
User.where(active: true).sqlreport.result.write_csv("active_users.csv")

# Or with more options
Post.where(published: true)
    .order(created_at: :desc)
    .limit(100)
    .sqlreport
    .result
    .to_csv(include_headers: true, separator: ",")

# Use batch processing with ActiveRecord
User.where(created_at: 1.month.ago..Time.current)
    .sqlreport_batch(batch_size: 500)
    .stream_to_csv("new_users.csv")

This integration makes it easy to generate reports directly from your models without having to write raw SQL.

• Add simple safeguard validations
• Allow it to use different databases
• Batch jobs (for bigger tables)
• Tie into Rails models
• Add support for multiple export options (PDF, textfile, LaTex)
• ..

1. Fork it ( https://github.com/gem-shards/sqlreport/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

The gem is available as open source under the terms of the MIT License.