Class: RelationalGroupedDataset

eclairjs/sql. RelationalGroupedDataset

new RelationalGroupedDataset()

Source:

Methods

agg()

Compute aggregates by specifying a series of aggregate columns. Note that this function by default retains the grouping columns in its output. To not retain grouping columns, set spark.sql.retainGroupColumns to false. The available aggregate methods are defined in functions.
Parameters:
Name Type Description
columnExpr,...columnExpr module:eclairjs/sql.Column | string or columnName, ...columnName
Since:
  • EclairJS 0.1 Spark 1.3.0
Source:
Returns:
module:eclairjs/sql.Dataset}
Example
// Java:
df.groupBy("department").agg(max("age"), sum("expense"));

avg(cols)

Compute the avg value for each numeric columns for each group.
Parameters:
Name Type Description
cols Array.<string>
Source:
Returns:
module:eclairjs/sql.Dataset}

count()

Count the number of rows for each group.
Source:
Returns:
module:eclairjs/sql.Dataset}

max(cols)

Compute the max value for each numeric columns for each group.
Parameters:
Name Type Description
cols Array.<string>
Source:
Returns:
module:eclairjs/sql.Dataset}

mean(cols)

Compute the mean value for each numeric columns for each group.
Parameters:
Name Type Description
cols Array.<string>
Source:
Returns:
module:eclairjs/sql.Dataset}

min(cols)

Compute the min value for each numeric columns for each group.
Parameters:
Name Type Description
cols Array.<string>
Source:
Returns:
module:eclairjs/sql.Dataset}

pivot(pivotColumn, valuesopt) → {module:eclairjs/sql.RelationalGroupedDataset}

Pivots a column of the current DataFrame and perform the specified aggregation. There are two versions of pivot function: one that requires the caller to specify the list of distinct values to pivot on, and one that does not. The latter is more concise but less efficient, because Spark needs to first compute the list of distinct values internally.
Parameters:
Name Type Attributes Description
pivotColumn string Name of the column to pivot.
values module:eclairjs.List <optional>
 List of values that will be translated to columns in the output DataFrame.
Since:
  • EclairJS 0.1 Spark 1.6.0
Source:
Returns:
Type
module:eclairjs/sql.RelationalGroupedDataset
Example
// Compute the sum of earnings for each year by course with each course as a separate column
  df.groupBy("year").pivot("course", new List(["dotNET", "Java"])).sum("earnings")

  // Or without specifying column values (less efficient)
  df.groupBy("year").pivot("course").sum("earnings")

sum(cols)

Compute the sum value for each numeric columns for each group.
Parameters:
Name Type Description
cols Array.<string>
Source:
Returns:
module:eclairjs/sql.Dataset}