Field Management

Field Management — All 30 Types

Every field-modification operation goes through the REST API or the nc CLI. MCP only reads schema (getTableSchema).

For per-type payload examples, see api-reference/references/field-types.md — that file is the authoritative catalog. This skill focuses on the workflow: how to plan, apply, and verify a field change.

Workflow

1. mcp__nocodb__getTableSchema  ← snapshot existing columns
2. Plan the new field (title, type, options)
3. nc field:create   OR   POST /api/v3/meta/bases/{baseId}/tables/{tableId}/fields
4. mcp__nocodb__getTableSchema  ← confirm field appeared
5. (optional) mcp__nocodb__queryRecords ← spot-check record render

Field Types Cheat Sheet

Create a Field — General Pattern

CLI:

nc field:create <baseId> <tableId> '<JSON payload>'

API:

curl -sS -X POST \
  -H "xc-token: $NOCODB_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '<JSON payload>' \
  "$NOCODB_URL/api/v3/meta/bases/$BASE_ID/tables/$TABLE_ID/fields"

Quick examples (one per category)

Text:

{ "title": "Description", "type": "LongText" }

Numeric:

{ "title": "Price", "type": "Currency", "currency_code": "USD" }

Date:

{ "title": "Due", "type": "Date", "date_format": "YYYY-MM-DD" }

Selection:

{
  "title": "Priority",
  "type": "SingleSelect",
  "colOptions": { "options": [
    {"title":"Low"}, {"title":"Medium"}, {"title":"High"}
  ]}
}

Attachment:

{ "title": "Files", "type": "Attachment" }

Link (modern):

{
  "title": "Orders",
  "type": "Links",
  "linked_table_id": "<otherTableId>",
  "type_of_relation": "hm"
}

Lookup (after a link exists):

{
  "title": "Customer Name",
  "type": "Lookup",
  "fk_relation_column_id": "<linkColumnId>",
  "fk_lookup_column_id":   "<columnIdOnLinkedTable>"
}

Rollup:

{
  "title": "Order Total",
  "type": "Rollup",
  "fk_relation_column_id": "<linkColumnId>",
  "fk_rollup_column_id":   "<numericColumnIdOnLinkedTable>",
  "rollup_function":       "sum"
}

Formula:

{
  "title": "Days Open",
  "type": "Formula",
  "formula": "DATETIME_DIFF(NOW(), {CreatedAt}, \"days\")"
}

Button (URL action):

{
  "title": "Open Doc",
  "type": "Button",
  "label": "Open",
  "action": { "type": "url", "url": "https://docs.example.com/{Id}" }
}

Barcode / QrCode (refer to another column):

{ "title": "SKU Barcode", "type": "Barcode", "fk_column_id": "<sourceColumnId>", "barcode_format": "CODE128" }
{ "title": "Order QR",    "type": "QrCode",  "fk_column_id": "<sourceColumnId>" }

Rename a Field

nc field:update <baseId> <tableId> <columnId> '{"title":"NewName"}'

API:

curl -sS -X PATCH \
  -H "xc-token: $NOCODB_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title":"NewName"}' \
  "$NOCODB_URL/api/v3/meta/bases/$BASE_ID/fields/$FIELD_ID"

Renames are by ID, so existing Lookups / Rollups / Formulas referencing this column keep working. Formulas displayed by-name ({Name}) update to use the new title automatically.

Change Field Type

nc field:update <baseId> <tableId> <columnId> '{"type":"LongText"}'

NocoDB validates the change against existing data:

Always count records first to gauge impact — see mcp-patterns "Audit Scope Before a Bulk Migration".

Update Field Options

For SingleSelect / MultiSelect, send the full options array (NocoDB diffs it):

nc field:update <baseId> <tableId> <columnId> '{
  "colOptions": {
    "options": [
      {"id":"<existingOptionId>","title":"Existing"},
      {"title":"NewOption"}
    ]
  }
}'

To rename an option, keep its id. To delete an option, omit it from the array — but NocoDB does not migrate records that hold the deleted value; they keep showing it as invalid.

Delete a Field

Destructive — confirm with the user first. Print the field title, type, and any dependents (Lookups / Rollups / Formulas referencing it).

nc field:delete <baseId> <tableId> <columnId>

API:

curl -sS -X DELETE \
  -H "xc-token: $NOCODB_API_TOKEN" \
  "$NOCODB_URL/api/v3/meta/bases/$BASE_ID/fields/$FIELD_ID"

Pre-delete audit (find dependents):

mcp__nocodb__getTableSchema  tableId: <tableId>
# Look at every other field's options for fk_lookup_column_id / fk_rollup_column_id == <columnId>
# And every Formula's `formula` string for {<columnTitle>}

If the field is used as a display_field for a linked table, NocoDB will pick a new display field automatically — but the linked-record dropdowns will show the new value.

Field-Specific Workflows

Setting up a Link → Lookup → Rollup chain

The classic CRM pattern: each Order has one Customer; surface customer name on the Order; sum order totals back on the Customer.

1. nc field:create <base> <ordersTableId>     '{"title":"Customer", "type":"Links", "linked_table_id":"<customersTableId>", "type_of_relation":"bt"}'
2. nc field:list   <base> <ordersTableId>     # find the new link's columnId   → c_link
3. nc field:list   <base> <customersTableId>  # find Customer.Name's columnId  → c_name
4. nc field:create <base> <ordersTableId>     '{"title":"Customer Name", "type":"Lookup", "fk_relation_column_id":"c_link", "fk_lookup_column_id":"c_name"}'

# Inverse rollup (on Customers, summing Orders.Amount)
5. nc field:list   <base> <customersTableId>  # find auto-created inverse link → c_orders_link
6. nc field:list   <base> <ordersTableId>     # find Orders.Amount             → c_amount
7. nc field:create <base> <customersTableId>  '{"title":"Lifetime Value", "type":"Rollup", "fk_relation_column_id":"c_orders_link", "fk_rollup_column_id":"c_amount", "rollup_function":"sum"}'

Formula validation

Formula errors appear at create time but also at runtime per-row. After creating a Formula, query 2–3 records to spot-check:

mcp__nocodb__queryRecords
  tableId: <tableId>
  fields: ["Title", "<formulaFieldName>"]
  pageSize: 3

If a row's formula returns ERR, the formula references a nullable column or has a type mismatch — IF(ISBLANK({Field}), "", calculation) is the standard guard.

System fields

CreatedTime, LastModifiedTime, CreatedBy, LastModifiedBy can be added to any table but are populated automatically. They are read-only via the Data API. Use them for audit columns; do not try to seed them from a CSV import.

Troubleshooting