Numeric

The exact decimal a numeric column holds, for values a JavaScript number cannot carry without losing digits. numeric decodes to a plain number whenever a double round-trips it faithfully (prints back the same digits), and to a Numeric instance otherwise, the same contract int8 has with number/BigInt. See Data Types & Type Mapping for when each happens and why.

const r = await connection.query("select 12345678901234567.89::numeric as v");
r.rows[0][0];                    // Numeric { value: '12345678901234567.89' }
r.rows[0][0].toString();         // '12345678901234567.89' - exact
r.rows[0][0].toNumber();         // 12345678901234568 - lossy, on purpose

Constructor

new Numeric(value: string | number | bigint)

Argument	Type	Description
value	string | number | bigint	Stored as-is if a string, otherwise stringified

Properties

Key	Type	Readonly	Description
value	string	true	The decimal exactly as PostgreSQL wrote it

Methods

Method	Returns	Description
toString()	string	The exact decimal; casts back through ::numeric
toPostgres()	string	Same as toString() — the pg-convention name for "write yourself back"
toJSON()	string	Same as toString(). Unlike the other value classes, Numeric wraps a single decimal, so its JSON value is that string, not {"value":"..."}
toNumber()	number	The value as a double — lossy, which is the point of this class

There is deliberately no valueOf(). Numeric implements Symbol.toPrimitive, returning the exact text for every hint, so String(n)/`${n}` are lossless, and n + 1 concatenates rather than silently rounding through an implicit number coercion. Reach for toNumber() when a lossy double is actually what's wanted.

Numeric is a class rather than a bare string so it can be told apart from one: determine() types a bare string as varchar, which PostgreSQL then refuses to store in a numeric column. A Numeric round-trips as a parameter the same way it decoded.