@clickhouse/client 1.7.0

Bug fixes

(Web only) Fixed an issue where streaming large datasets could provide corrupted results. See #333 (PR) for more details.

New features

Added JSONEachRowWithProgress format support, ProgressRow interface, and isProgressRow type guard. See this Node.js example for more details. It should work similarly with the Web version.

(Experimental) Exposed the parseColumnType function that takes a string representation of a ClickHouse type (e.g., FixedString(16), Nullable(Int32), etc.) and returns an AST-like object that represents the type. For example:

for (const type of [
  'Int32',
  'Array(Nullable(String))',
  `Map(Int32, DateTime64(9, 'UTC'))`,
]) {
  console.log(`##### Source ClickHouse type: ${type}`)
  console.log(parseColumnType(type))
}

The above code will output:

##### Source ClickHouse type: Int32
{ type: 'Simple', columnType: 'Int32', sourceType: 'Int32' }
##### Source ClickHouse type: Array(Nullable(String))
{
  type: 'Array',
  value: {
    type: 'Nullable',
    sourceType: 'Nullable(String)',
    value: { type: 'Simple', columnType: 'String', sourceType: 'String' }
  },
  dimensions: 1,
  sourceType: 'Array(Nullable(String))'
}
##### Source ClickHouse type: Map(Int32, DateTime64(9, 'UTC'))
{
  type: 'Map',
  key: { type: 'Simple', columnType: 'Int32', sourceType: 'Int32' },
  value: {
    type: 'DateTime64',
    timezone: 'UTC',
    precision: 9,
    sourceType: "DateTime64(9, 'UTC')"
  },
  sourceType: "Map(Int32, DateTime64(9, 'UTC'))"
}

While the original intention was to use this function internally for Native/RowBinaryWithNamesAndTypes data formats headers parsing, it can be useful for other purposes as well (e.g., interfaces generation, or custom JSON serializers).

NB: currently unsupported source types to parse:

Geo
(Simple)AggregateFunction
Nested
Old/new experimental JSON
Dynamic
Variant