Class: Blazer::Adapters::PrestoAdapter

Inherits:
BaseAdapter show all
Defined in:
lib/blazer/adapters/presto_adapter.rb

Instance Attribute Summary

Attributes inherited from BaseAdapter

#data_source

Instance Method Summary collapse

Methods inherited from BaseAdapter

#cachable?, #cancel, #cohort_analysis_statement, #cost, #explain, #initialize, #reconnect, #schema, #supports_cohort_analysis?

Constructor Details

This class inherits a constructor from Blazer::Adapters::BaseAdapter

Instance Method Details

#parameter_binding ⇒ Object

TODO support prepared statements - prestodb.io/docs/current/sql/prepare.html feature request for variables - github.com/prestodb/presto/issues/5918



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# File 'lib/blazer/adapters/presto_adapter.rb', line 34

def parameter_binding
end

#preview_statement ⇒ Object 



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# File 'lib/blazer/adapters/presto_adapter.rb', line 24

def preview_statement
  "SELECT * FROM {table} LIMIT 10"
end

#quoting ⇒ Object 



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# File 'lib/blazer/adapters/presto_adapter.rb', line 28

def quoting
  :single_quote_escape
end

#run_statement(statement, comment) ⇒ Object 



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# File 'lib/blazer/adapters/presto_adapter.rb', line 4

def run_statement(statement, comment)
  columns = []
  rows = []
  error = nil

  begin
    columns, rows = client.run("#{statement} /*#{comment}*/")
    columns = columns.map(&:name)
  rescue => e
    error = e.message
  end

  [columns, rows, error]
end

#tables ⇒ Object 



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# File 'lib/blazer/adapters/presto_adapter.rb', line 19

def tables
  _, rows = client.run("SHOW TABLES")
  rows.map(&:first)
end