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Version: Java (Groovy)

firstBy

firstBy returns the first row for each group.

Syntax​

table.firstBy()
table.firstBy(groupByColumns...)

Parameters​

ParameterTypeDescription
groupByColumnsString...

The column(s) by which to group data.

  • NULL returns only the first row in the table.
  • "X" will output the entire first row of each group in column X.
  • "X", "Y" will output the entire first row of each group designated from the X and Y columns.
groupByColumnsColumnName...

The column(s) by which to group data.

  • NULL returns only the first row in the table.
  • "X" will output the entire first row of each group in column X.
  • "X", "Y" will output the entire first row of each group designated from the X and Y columns.
groupByColumnsCollection<String>

The column(s) by which to group data.

  • NULL returns only the first row in the table.
  • "X" will output the entire first row of each group in column X.
  • "X", "Y" will output the entire first row of each group designated from the X and Y columns.

Returns​

A new table containing the first row for each group.

Examples​

In this example, firstBy returns the first row of the table.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.firstBy()

In this example, firstBy returns the first row, as grouped by X.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.firstBy("X")

In this example, firstBy returns the first row, as grouped by X and Y.

source = newTable(
    stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
    stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
    intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)

result = source.firstBy("X", "Y")