TYPE_PARSERS.md

Type parsers

Type parsers describe how to parse PostgreSQL types.

type TypeParserType = {|
  +name: string,
  +parse: (value: string) => *
|};

Example:

{
  name: 'int8',
  parse: (value) => {
    return parseInt(value, 10);
  }
}

Note: Unlike pg-types that uses OIDs to identify types, Slonik identifies types using their names.

Use this query to find type names:

SELECT
  typname
FROM pg_type
ORDER BY typname ASC

Type parsers are configured using typeParsers client configuration.

Read: Default type parsers.

Built-in type parsers

Type name	Implemnetation	Factory function name
date	Produces a literal date as a string (format: YYYY-MM-DD).	createDateTypeParser
int8	Produces an integer.	createBigintTypeParser
interval	Produces interval in seconds (integer).	createIntervalTypeParser
numeric	Produces a float.	createNumericTypeParser
timestamp	Produces a unix timestamp (in milliseconds).	createTimestampTypeParser
timestamptz	Produces a unix timestamp (in milliseconds).	createTimestampWithTimeZoneTypeParser

Built-in type parsers can be created using the exported factory functions, e.g.

import {
  createTimestampTypeParser
} from 'slonik';

createTimestampTypeParser();

// {
//   name: 'timestamp',
//   parse: (value) => {
//     return value === null ? value : Date.parse(value);
//   }
// }