caseWhen

function caseWhen<T>(...args): CaseWhenOutput<T>;

Defined in: packages/db/src/query/builder/functions.ts:494

Returns the value for the first matching condition, similar to SQL CASE WHEN.

Arguments are evaluated as condition/value pairs followed by an optional default value. Scalar branch values return a query expression and can be used in expression contexts like select, where, orderBy, groupBy, having, and equality join operands. If no scalar branch matches and no default is provided, the result is null.

When a branch value is a projection object, caseWhen becomes a select-only projection value. Projection branches can include nested fields, ref spreads, and includes. If no projection branch matches and no default is provided, the result is undefined.

Type Parameters#

T#

T extends [ExpressionLike, CaseWhenValue, ...CaseWhenValue[]]

Parameters#

args#

...T & T extends [unknown, unknown, ...Rest[]] ? [ExpressionLike, CaseWhenValue, ...(Rest extends [unknown, unknown, ...Rest[]] ? [ExpressionLike, CaseWhenValue, ...(Rest extends [unknown, unknown, ...Rest[]] ? [ExpressionLike, CaseWhenValue, ...(Rest extends [unknown, unknown, ...Rest[]] ? [ExpressionLike, CaseWhenValue, ...(Rest extends [(...), (...), ...(...)[]] ? [(...), (...), ...(...)[]] : Rest)[]] : Rest)[]] : Rest)[]] : Rest)[]] : T

Returns#

CaseWhenOutput<T>

Examples#

caseWhen(gt(user.age, 18), `adult`, `minor`)

caseWhen(
  gt(user.age, 65),
  `senior`,
  gt(user.age, 18),
  `adult`,
  `minor`,
)

caseWhen(gt(user.age, 18), {
  ...user,
  posts: include(
    q
      .from({ post: postsCollection })
      .where(({ post }) => eq(post.userId, user.id)),
  ),
})