Class: QuickCount::Adapters::Mysql

Inherits:
Base
  • Object
show all
Defined in:
lib/quick_count/adapters/mysql.rb

Instance Attribute Summary

Attributes inherited from Base

#connection

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from QuickCount::Adapters::Base

Instance Method Details

#count_estimate(query) ⇒ Object 



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# File 'lib/quick_count/adapters/mysql.rb', line 25

def count_estimate(query)
  # Use EXPLAIN to get row estimate
  result = execute_sql("EXPLAIN #{query}")

  # Parse the rows from EXPLAIN output
  # MySQL EXPLAIN returns different formats, try to extract rows estimate
  if result.respond_to?(:each)
    result.each do |row|
      if row['rows']
        return row['rows'].to_i
      elsif row['Extra'] && row['Extra'].match(/rows=(\d+)/)
        return $1.to_i
      end
    end
  end

  # Fallback: try to extract from query if it's a simple SELECT
  if query.match(/FROM\s+(\w+)/i)
    table_name = $1
    return get_table_rows_estimate(table_name)
  end

  # Last resort - return 0
  0
end

#quick_count(table_name, threshold: nil) ⇒ Object 



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# File 'lib/quick_count/adapters/mysql.rb', line 10

def quick_count(table_name, threshold: nil)
  threshold ||= 500_000

  # Get estimated count from INFORMATION_SCHEMA
  estimated_count = get_table_rows_estimate(table_name)

  if estimated_count < threshold
    # Use exact count for small tables
    result = execute_sql("SELECT COUNT(*) as count FROM #{quote_identifier(table_name)}")
    result[0]['count'].to_i
  else
    estimated_count
  end
end

#supported? ⇒ Boolean

Returns:



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# File 'lib/quick_count/adapters/mysql.rb', line 6

def supported?
  connection.adapter_name.downcase.match?(/mysql/)
end