Column ${column.field} is not nullable and has no default va

Error message

Column ${column.field} is not nullable and has no default value

What it means

Before generating an INSERT, shouldOmitColumnInInsert validates each NOT NULL column: it must either have a user-supplied default, a database default, or be an identity column. If a NOT NULL column has none of these, the generated INSERT would inevitably fail (or produce an incomplete statement), so the builder throws immediately with the column name. This is a frontend pre-flight check mirroring what the database would reject anyway.

Source

Thrown at frontend/src/lib/components/apps/components/display/dbtable/queries/insert.ts:76

		})
		.join(', ')

	return defaultValues
}

function shouldOmitColumnInInsert(column: ColumnDef) {
	if (!column.hideInsert || column.isidentity === ColumnIdentity.Always) {
		return true
	}

	const userDefaultValue =
		(column.defaultUserValue !== undefined && column.defaultUserValue !== '') ||
		column.defaultValueNull === true
	const dbDefaultValue = Boolean(column.defaultvalue)

	if (column.isnullable === 'NO') {
		if (!userDefaultValue && !dbDefaultValue && column.isidentity === ColumnIdentity.No) {
			throw new Error(`Column ${column.field} is not nullable and has no default value`)
		}

		if (!userDefaultValue && !dbDefaultValue) {
			// Should be omitted if it's an identity column and we have no default value
			return column.isidentity !== ColumnIdentity.No
		}

		// Should be omitted if the user had not provided a default value and the database has a default value
		return !userDefaultValue && dbDefaultValue
	} else if (column.isnullable === 'YES') {
		return !userDefaultValue
	}

	return false
}

export function makeInsertQuery(table: string, columns: ColumnDef[], dbType: DbType) {
	if (!table) throw new Error('Table name is required')

View on GitHub (pinned to e474e8803c)

Solutions

Give the column a default value in the database (ALTER TABLE ... ALTER COLUMN ... SET DEFAULT) so dbDefaultValue becomes true.
Provide a defaultUserValue or enable defaultValueNull for the column in the table editor configuration.
Make the column nullable, or define it as an identity/auto-increment column so it can be omitted from the INSERT.
Exclude the column from the insert form if it is populated by triggers or application logic.

Example fix

-- before: column rejects inserts
CREATE TABLE users (id SERIAL, email TEXT NOT NULL)
-- after
ALTER TABLE users ALTER COLUMN email SET DEFAULT 'unknown@example.com'

Defensive patterns

Strategy: validation

Validate before calling

const bad = columns.filter((c) =>
  c.isnullable === 'NO' && !c.defaultvalue &&
  c.isidentity === ColumnIdentity.No &&
  !c.defaultUserValue && c.defaultValueNull !== true &&
  c.isidentity !== ColumnIdentity.Always && !c.hideInsert
)
if (bad.length) throw new Error(`Columns need a default: ${bad.map((c) => c.field).join(', ')}`)

Type guard

function canInsert(c: ColumnDef): boolean {
  if (c.isnullable !== 'NO') return true
  return Boolean(c.defaultvalue) || c.isidentity !== ColumnIdentity.No ||
    Boolean(c.defaultUserValue) || c.defaultValueNull === true
}

Try / catch

try {
  const query = makeInsertQuery(table, columns, dbType)
} catch (e) {
  const m = e instanceof Error && e.message.match(/Column (\S+) is not nullable/)
  if (m) {
    alert(`Set a default for column "${m[1]}" in the database or the insert form`)
    return
  }
  throw e
}

Prevention

Define DEFAULT values on all NOT NULL columns at schema design time
Use identity/auto-increment for surrogate keys instead of NOT NULL plain columns
Keep column metadata (isnullable, defaultvalue, isidentity) fresh by reloading the table schema
Set defaultUserValue or defaultValueNull in the editor for NOT NULL columns you must fill client-side

When it happens

Trigger: Building an insert query where a column has isnullable === 'NO', no defaultvalue, isidentity === ColumnIdentity.No, and the user provided neither defaultUserValue nor checked defaultValueNull — e.g. adding a new NOT NULL column to a table without a default and then opening the insert dialog.

Common situations: A DBA adds NOT NULL DEFAULT-less columns to a table after the app was built; column metadata fetched from the DB shows isnullable 'NO' but the frontend schema has no default config; identity detection failed so an auto-increment column is reported as ColumnIdentity.No.

Related errors

AI-assisted analysis of windmill-labs/windmill@e474e8803c (2026-09-03). Data as JSON: /api/errors/6bcf4214076c65d9. Report an issue: GitHub.