MRT logoMaterial React Table

    Aggregation and Grouping Feature Guide

    Material React Table has built-in grouping and aggregation features. There are options for both automatic client-side grouping and aggregation, as well as manual server-side grouping and aggregation. This guide will walk you through the different options and how to use and customize them.

    Relevant Props

    #
    Prop Name
    Type
    Default Value
    More Info Links
    1
    Record<string, AggregationFn>
    		TanStack Table Grouping Docs
    2
    boolean
    true
    		MRT Expanding Sub Rows Docs
    3
    boolean
    		MRT Aggregation and Grouping Docs
    4
    boolean
    5
    (table: Table<TData>) => () => RowModel<TData>
    		TanStack Table Grouping Docs
    6
    false | 'reorder' | 'remove'
    reorder
    		TanStack Table Grouping Docs
    7
    boolean
    		TanStack Table Grouping Docs
    8
    ChipProps| ({ table }} => ChipProps
    		Material UI Chip Props
    9
    OnChangeFn<GroupingState>
    		TanStack Table Grouping Docs
    10
    'bottom' | 'top' | 'none'

    Relevant Column Options

    #
    Column Option
    Type
    Default Value
    More Info Links
    1
    ({ cell, column, row, table }) => ReactNode
    2
    ReactNode | ({ column, footer, table }) => ReactNode
    		MRT Data Columns Docs
    3
    ({ cell, column, row, table }) => ReactNode
    4
    boolean

    Relevant State

    #
    State Option
    Type
    Default Value
    More Info Links
    1
    Record<string, boolean> | boolean
    {}
    		TanStack Table Expanding Docs
    2
    Array<string>
    []
    		TanStack Table Grouping Docs

    Enable Grouping

    To enable grouping, set the enableGrouping prop to true. This will both add a drag handle button so that columns can be dragged to the dropzone to be grouped and will add an entry column actions menu to group or ungroup a column.

    <MaterialReactTable columns={columns} data={data} enableGrouping />

    Disable Grouping Per Column 

    const columns = [
      {
        accessorKey: 'name',
        header: 'Name',
        enableGrouping: false, // disable grouping for this column
      },
      {
        accessorKey: 'age',
        header: 'Age',
      },
    ];
    

    return <MaterialReactTable columns={columns} data={data} enableGrouping />;

    Hide Drag Buttons for Grouping

    If you do not want the drag buttons that come with the grouping feature, you can independently disable them without disabling the grouping feature entirely by setting the enableColumnDragging prop to false.

    <MaterialReactTable
      columns={columns}
      data={data}
      enableGrouping
      enableColumnDragging={false} //do not show drag handle buttons, but still show grouping options in column actions menu
    />

    Group Columns by Default

    If you want columns to be grouped by default, you can set the grouping state in either the initialState or state prop.

    <MaterialReactTable
      columns={columns}
      data={data}
      enableGrouping
      initialState={{ grouping: ['location', 'department'] }} //group by location and department by default
    />

    Expand Grouped Rows by Default

    In addition to grouping columns by default, you may also want those grouped rows to be expanded and visible by default, too. You can do this by setting the expanded state to true in either the initialState or state prop.

    <MaterialReactTable
      columns={columns}
      data={data}
      enableGrouping
      initialState={{
        grouping: ['location', 'department'], //group by location and department by default and expand grouped rows
        expanded: true, //show grouped rows by default
      }}
    />

    Aggregation on Grouped Rows

    One of the cool features of Material React Table is that it can automatically aggregate the data in grouped rows. To enable this, you must specify both an aggregationFn and an AggregatedCell render option on a column definition.

    Built-in Aggregation Functions

    There are several built-in aggregation functions available that you can use. They are:

    • count - Finds the number of rows in a group

    • extent - Finds the minimum and maximum values of a group of rows

    • max - Finds the maximum value of a group of rows

    • mean - Finds the average value of a group of rows

    • median - Finds the median value of a group of rows

    • min - Finds the minimum value of a group of rows

    • sum - sums the values of a group of rows

    • uniqueCount - Finds the number of unique values of a group of rows

    • unique - Finds the unique values of a group of rows

    All of these built-in aggregation functions are from TanStack Table

    const columns = [
      {
        accessorKey: 'team', //grouped by team in initial state below
        header: 'Team',
      },
      {
        accessorKey: 'player',
        header: 'Player',
      },
      {
        accessorKey: 'points',
        header: 'Points',
        aggregationFn: 'sum', //calc total points for each team by adding up all the points for each player on the team
        AggregatedCell: ({ cell }) => <div>Team Score: {cell.getValue()}</div>,
      },
    ];
    

    return (
      <MaterialReactTable
        columns={columns}
        data={data}
        enableGrouping
        initialState={{ grouping: ['team'], expanded: true }}
      />
    );

    Custom Aggregation Functions

    If none of these pre-built aggregation functions work for you, you can also pass in a custom aggregation function. The aggregation function will be passed in an array of values from the column that you are aggregating. It should return a single value that will be displayed in the aggregated cell.

    If you are specifying a custom aggregation function, it must implement the following type:

    export type AggregationFn<TData extends AnyData> = (
      getLeafRows: () => Row<TData>[],
      getChildRows: () => Row<TData>[]
    ) => any

    Material React Table does not automatically aggregate all rows for you to calculate totals for the entire table. However, it is still easy enough to do this manually and add in your custom calculations into the footer or Footer of a column definition. It is recommended that you do any necessary aggregation calculations on your data in a useMemo hook before passing it to the columns footer in your columns definition.

    //calculate the total points for all players in the table in a useMemo hook
    const averageScore = useMemo(() => {
      const totalPoints = data.reduce((acc, row) => acc + row.points, 0);
      const totalPlayers = data.length;
      return totalPoints / totalPlayers;
    }, [data]);
    

    const columns = [
      {
        accessorKey: 'name',
        header: 'Name',
      },
      {
        accessorKey: 'score',
        header: 'Score',
        Footer: () => <div>Average Score: {averageScore}</div>, //do not do calculations in render, do them in useMemo hook and pass them in here
      },
    ];

    Please remember to perform heavy aggregation calculations in a useMemo hook to avoid unnecessary re-renders!

    Custom Cell Renders for Aggregation and Grouping

    There are a few custom cell render overrides that you should be aware of when using grouping and aggregation features.

    AggregatedCell Column Option

    "Aggregation Cells" are cells in an aggregated row (not a normal data row) that can display aggregates (avg, sum, etc.) of the data in a group. The cell that the table is grouped on, however, is not an Aggregate Cell, but rather a GroupedCell.

    You can specify the custom render for these cells with the AggregatedCell render option on a column definition.

    const columns = [
      {
        accessorKey: 'points',
        header: 'Points',
        aggregationFn: 'sum',
        AggregatedCell: ({ cell }) => <div>Total Score: {cell.getValue()}</div>,
      },
    ];

    GroupedCell Column Option

    "Grouped Cells" are cells in a grouped row (not a normal data row) that by default display the value that the rows are grouped on and the number of rows in the group. You can override the default render for these cells with the GroupedCell render option on a column definition.

    const columns = [
      {
        accessorKey: 'team',
        header: 'Team',
        GroupedCell: ({ cell }) => <div>Team: {cell.getValue()}</div>,
      },
    ];

    Aggregation/Grouping Example

    Demo

    Open StackblitzOpen Code SandboxOpen on GitHub
    State
    First Name
    Last Name
    Age
    Gender
    Salary
    Alabama (7)Oldest by State:
    64
    		Average by State:
    $43,375
    ThadWiegand64Female$56,146
    AliviaLedner56Male$12,591
    DanykaGleason36Male$71,238
    LionelHartmann30Nonbinary$58,743
    ReinholdReichel30Female$30,531
    LurlineKoepp59Female$10,645
    KodyBraun38Female$63,733
    Alaska (8)Oldest by State:
    59
    		Average by State:
    $68,901
    EloisaKohler31Male$45,801
    KianHand56Male$81,062
    LoyceSchmidt29Female$76,295
    MichaleCollier59Male$75,197
    EldridgeStroman42Male$59,594
    AlveraBalistreri25Female$79,844
    KaydenEmard35Female$98,252
    DomingoBauch36Female$35,159
    Arizona (1)Oldest by State:
    22
    		Average by State:
    $54,027
    GunnerRolfson22Male$54,027
    Arkansas (4)Oldest by State:
    52
    		Average by State:
    $58,194
    Max Age:
    65
    Average Salary:
    $56,319

    Rows per page

    1-20 of 249

    Source Code 

    1import React, { FC, useMemo } from 'react';
    2import { Box, Stack } from '@mui/material';
    3import MaterialReactTable, { MRT_ColumnDef } from 'material-react-table';
    4import { data, Person } from './makeData';
    5

    6const Example: FC = () => {
    7  const averageSalary = useMemo(
    8    () => data.reduce((acc, curr) => acc + curr.salary, 0) / data.length,
    9    [],
    10  );
    11

    12  const maxAge = useMemo(
    13    () => data.reduce((acc, curr) => Math.max(acc, curr.age), 0),
    14    [],
    15  );
    16

    17  const columns = useMemo<MRT_ColumnDef<Person>[]>(
    18    () => [
    19      {
    20        header: 'First Name',
    21        accessorKey: 'firstName',
    22        enableGrouping: false, //do not let this column be grouped
    23      },
    24      {
    25        header: 'Last Name',
    26        accessorKey: 'lastName',
    27      },
    28      {
    29        header: 'Age',
    30        accessorKey: 'age',
    31        aggregationFn: 'max', //show the max age in the group (lots of pre-built aggregationFns to choose from)
    32        //required to render an aggregated cell
    33        AggregatedCell: ({ cell, table }) => (
    34          <>
    35            Oldest by{' '}
    36            {table.getColumn(cell.row.groupingColumnId ?? '').columnDef.header}:{' '}
    37            <Box
    38              sx={{ color: 'info.main', display: 'inline', fontWeight: 'bold' }}
    39            >
    40              {cell.getValue<number>()}
    41            </Box>
    42          </>
    43        ),
    44        Footer: () => (
    45          <Stack>
    46            Max Age:
    47            <Box color="warning.main">{Math.round(maxAge)}</Box>
    48          </Stack>
    49        ),
    50      },
    51      {
    52        header: 'Gender',
    53        accessorKey: 'gender',
    54        //optionally, customize the cell render when this column is grouped. Make the text blue and pluralize the word
    55        GroupedCell: ({ cell, row }) => (
    56          <Box sx={{ color: 'primary.main' }}>
    57            <strong>{cell.getValue<string>()}s </strong> ({row.subRows?.length})
    58          </Box>
    59        ),
    60      },
    61      {
    62        header: 'State',
    63        accessorKey: 'state',
    64      },
    65      {
    66        header: 'Salary',
    67        accessorKey: 'salary',
    68        aggregationFn: 'mean',
    69        //required to render an aggregated cell, show the average salary in the group
    70        AggregatedCell: ({ cell, table }) => (
    71          <>
    72            Average by{' '}
    73            {table.getColumn(cell.row.groupingColumnId ?? '').columnDef.header}:{' '}
    74            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    75              {cell.getValue<number>()?.toLocaleString?.('en-US', {
    76                style: 'currency',
    77                currency: 'USD',
    78                minimumFractionDigits: 0,
    79                maximumFractionDigits: 0,
    80              })}
    81            </Box>
    82          </>
    83        ),
    84        //customize normal cell render on normal non-aggregated rows
    85        Cell: ({ cell }) => (
    86          <>
    87            {cell.getValue<number>()?.toLocaleString?.('en-US', {
    88              style: 'currency',
    89              currency: 'USD',
    90              minimumFractionDigits: 0,
    91              maximumFractionDigits: 0,
    92            })}
    93          </>
    94        ),
    95        Footer: () => (
    96          <Stack>
    97            Average Salary:
    98            <Box color="warning.main">
    99              {averageSalary?.toLocaleString?.('en-US', {
    100                style: 'currency',
    101                currency: 'USD',
    102                minimumFractionDigits: 0,
    103                maximumFractionDigits: 0,
    104              })}
    105            </Box>
    106          </Stack>
    107        ),
    108      },
    109    ],
    110    [averageSalary, maxAge],
    111  );
    112

    113  return (
    114    <MaterialReactTable
    115      columns={columns}
    116      data={data}
    117      enableGrouping
    118      enableStickyHeader
    119      enableStickyFooter
    120      initialState={{
    121        density: 'compact',
    122        expanded: true, //expand all groups by default
    123        grouping: ['state'], //an array of columns to group by by default (can be multiple)
    124        pagination: { pageIndex: 0, pageSize: 20 },
    125        sorting: [{ id: 'state', desc: false }], //sort by state by default
    126      }}
    127      muiToolbarAlertBannerChipProps={{ color: 'primary' }}
    128      muiTableContainerProps={{ sx: { maxHeight: 700 } }}
    129    />
    130  );
    131};
    132

    133export default Example;
    134

    Multiple Aggregations Per column

    New in v1.3!

    You may want to calculate more than one aggregation per column. This is now easier if you are upgraded to at least v1.3.0. You can now specify an array of aggregationFns, and then reference the aggregation results from an array in the AggregatedCell render option.

    const columns = [
      {
        header: 'Salary',
        accessorKey: 'salary',
        aggregationFn: ['count', 'mean'], //multiple aggregation functions
        AggregatedCell: ({ cell, table }) => (
          <div>
            {/*get the count from the first aggregation*/}
            <div>Count: {cell.getValue()[0]}</div>
            {/*get the average from the second aggregation*/}
            <div>Average Salary: {cell.getValue()[1]}</div>
          </div>
        ),
      },
    ];

    Demo

    Open StackblitzOpen Code SandboxOpen on GitHub
    State
    Gender
    First Name
    Last Name
    Salary
    Alabama (3)Count:
    7
    Average:
    $43,375
    Median:
    $35,619
    Min:
    $10,645
    Max:
    $71,238
    Female (4)Count:
    4
    Average:
    $40,264
    Median:
    $31,867
    Min:
    $10,645
    Max:
    $63,733
    ThadWiegand$56,146
    ReinholdReichel$30,531
    LurlineKoepp$10,645
    KodyBraun$63,733
    Male (2)Count:
    2
    Average:
    $41,915
    Median:
    $35,619
    Min:
    $12,591
    Max:
    $71,238
    AliviaLedner$12,591
    DanykaGleason$71,238
    Nonbinary (1)Count:
    1
    Average:
    $58,743
    Median:
    $29,372
    Min:
    $58,743
    Max:
    $58,743
    LionelHartmann$58,743
    Alaska (2)Count:
    8
    Average:
    $68,901
    Median:
    $49,126
    Min:
    $35,159
    Max:
    $98,252
    Male (4)Count:
    4
    Average:
    $65,414
    Median:
    $40,531
    Min:
    $45,801
    Max:
    $81,062
    EloisaKohler$45,801
    KianHand$81,062
    MichaleCollier$75,197
    EldridgeStroman$59,594
    Female (4)Count:
    4
    Average:
    $72,388
    Median:
    $49,126
    Min:
    $35,159
    Max:
    $98,252
    LoyceSchmidt$76,295
    AlveraBalistreri$79,844

    Rows per page

    1-20 of 342

    Source Code 

    1import React, { FC, useMemo } from 'react';
    2import { Box } from '@mui/material';
    3import MaterialReactTable, { MRT_ColumnDef } from 'material-react-table';
    4import { data, Person } from './makeData';
    5

    6const localeStringOptions = {
    7  style: 'currency',
    8  currency: 'USD',
    9  minimumFractionDigits: 0,
    10  maximumFractionDigits: 0,
    11};
    12

    13const Example: FC = () => {
    14  const columns = useMemo<MRT_ColumnDef<Person>[]>(
    15    () => [
    16      {
    17        header: 'First Name',
    18        accessorKey: 'firstName',
    19      },
    20      {
    21        header: 'Last Name',
    22        accessorKey: 'lastName',
    23      },
    24      {
    25        header: 'Gender',
    26        accessorKey: 'gender',
    27      },
    28      {
    29        header: 'State',
    30        accessorKey: 'state',
    31      },
    32      {
    33        header: 'Salary',
    34        accessorKey: 'salary',
    35        aggregationFn: ['count', 'mean', 'median', 'min', 'max'],
    36        //required to render an aggregated cell, show the average salary in the group
    37        AggregatedCell: ({ cell }) => (
    38          <>
    39            Count:{' '}
    40            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    41              {cell.getValue<Array<number>>()?.[0]}
    42            </Box>
    43            Average:{' '}
    44            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    45              {cell
    46                .getValue<Array<number>>()?.[1]
    47                ?.toLocaleString?.('en-US', localeStringOptions)}
    48            </Box>
    49            Median:{' '}
    50            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    51              {cell
    52                .getValue<Array<number>>()?.[2]
    53                ?.toLocaleString?.('en-US', localeStringOptions)}
    54            </Box>
    55            Min:{' '}
    56            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    57              {cell
    58                .getValue<Array<number>>()?.[3]
    59                ?.toLocaleString?.('en-US', localeStringOptions)}
    60            </Box>
    61            Max:{' '}
    62            <Box sx={{ color: 'success.main', fontWeight: 'bold' }}>
    63              {cell
    64                .getValue<Array<number>>()?.[4]
    65                ?.toLocaleString?.('en-US', localeStringOptions)}
    66            </Box>
    67          </>
    68        ),
    69        //customize normal cell render on normal non-aggregated rows
    70        Cell: ({ cell }) => (
    71          <>
    72            {cell
    73              .getValue<number>()
    74              ?.toLocaleString?.('en-US', localeStringOptions)}
    75          </>
    76        ),
    77      },
    78    ],
    79    [],
    80  );
    81

    82  return (
    83    <MaterialReactTable
    84      columns={columns}
    85      data={data}
    86      enableGrouping
    87      enableStickyHeader
    88      initialState={{
    89        density: 'compact',
    90        expanded: true, //expand all groups by default
    91        grouping: ['state', 'gender'], //an array of columns to group by by default (can be multiple)
    92        pagination: { pageIndex: 0, pageSize: 20 },
    93        sorting: [{ id: 'state', desc: false }], //sort by state by default
    94      }}
    95      muiToolbarAlertBannerChipProps={{ color: 'primary' }}
    96      muiTableContainerProps={{ sx: { maxHeight: 700 } }}
    97    />
    98  );
    99};
    100

    101export default Example;
    102

    Manual Grouping

    Manual Grouping means that the data that you pass to the table is already grouped and aggregated, and you do not want Material React Table to do any of the grouping or aggregation for you. This is useful if you are using a backend API to do the grouping and aggregation for you, and you just want to display the results. However, you will need to put your data in the specific format that the expanding features understand.