class BigShift::RedshiftTableSchema
Public Class Methods
new(schema_name, table_name, redshift_connection)
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# File lib/bigshift/redshift_table_schema.rb, line 3 def initialize(schema_name, table_name, redshift_connection) @schema_name = schema_name @table_name = table_name @redshift_connection = redshift_connection end
Public Instance Methods
columns()
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# File lib/bigshift/redshift_table_schema.rb, line 9 def columns @columns ||= begin query = %{ SELECT "column", "type", "notnull" FROM pg_table_def ptd, information_schema.columns isc WHERE ptd.schemaname = isc.table_schema AND ptd.tablename = isc.table_name AND ptd.column = isc.column_name AND schemaname = $1 AND tablename = $2 ORDER BY ordinal_position }.gsub(/\s+/, ' ').strip rows = @redshift_connection.exec_params(query, [@schema_name, @table_name]) if rows.count == 0 raise sprintf('Table %s for schema %s not found', @table_name.inspect, @schema_name.inspect) else columns = rows.map do |row| name = row['column'] type = row['type'] nullable = row['notnull'] == 'f' Column.new(name, type, nullable) end columns end end end
to_big_query()
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# File lib/bigshift/redshift_table_schema.rb, line 36 def to_big_query Google::Apis::BigqueryV2::TableSchema.new(fields: columns.map(&:to_big_query)) end