bigint-and-bigdecimal.md

BigInt and BigDecimal

Checkpoint provides support for BigInt, Decimal, BigDecimal. It's also possible to define custom (or define existing) decimal types.

MySQL mappings

BigInt and BigDecimal types are mapped to following MySQL types by default:

• BigInt -> BIGINT
• Decimal -> DECIMAL(10, 2)
• BigDecimal -> DECIMAL(20, 8)

Using BigInt and BigDecimal types

To use default (or custom) BigInt and BigDecimal type it needs to be predeclared in GraphQL schema using scalar keyword. Once it's declared it can be used as field's type.

scalar BigInt

type User {
  votes_count: BigInt
}  

{% hint style="warning" %} When writing to those fields make sure that you are using JavaScript type that mysql package understands and won't result in loss of precision. BigInt and String should be preferred. {% endhint %}

Custom decimal types

It's possible to define new or to redefine existing decimal types using advanced options.

const checkpoint = new Checkpoint(config, writer, schema, {
  decimalTypes: {
    Decimal: {
      p: 14,
      d: 10
    },
    BigDecimal: {
      p: 20,
      d: 8
    },
    EvenBiggerDecimal: {
      p: 40,
      d: 16
    }
  }
});