Add uint64 (and uint32?) type conversion methods to bloblang

[packman80]

After upgrading from v1 to v2 of library go-clickhouse ins't possible to write numbers (benthos) with UInt type in clickhouse and string to Date/Datetime type

For example: I create table experiment

CREATE TABLE default.experiment
(
    `count` UInt64
)
ENGINE = MergeTree
ORDER BY tuple()
SETTINGS index_granularity = 819

┏━━━━━━━| ┃ name | type | ┡━━━━━━━| │ count │ UInt64 │ └───────|

And have this config:

input:
  generate:
    interval: 10s
    mapping: 'root = {"count": 20}'
pipeline:
  threads: 1
  processors:
    - log:
        message: ${!this}
output:
  sql_insert:
    driver: clickhouse
    dsn: clickhouse://127.0.0.1:9000?database=default
    table: "experiment"
    columns: [
      count
      ]
    args_mapping: |
      root = [
        this.count
      ]
logger:
  level: ALL
  format: json
  add_timestamp: true
  static_fields:
    '@service': service

I got this error:

{"@service":"service","label":"","level":"error","msg":"Failed to send message to sql_insert: clickhouse [AppendRow]: count clickhouse [AppendRow]: converting int64 to UInt64 is unsupported","path":"root.output","time":"2022-09-01T13:02:07+03:00"}

In v1 version many of types conversion was under the hood of library, but in v2 they are don't do implicit conversion of types due to performance – https://github.com/ClickHouse/clickhouse-go/blob/examples/TYPES.md

Another problem with date/datetime types. In first version of go-clickhouse i used 'strings' for that ('2022-01-01') in benthos, but in v2 it's not possible.

Are there workarounds in benthos for this issues.

[Jeffail]

Hey @packman80, the timestamp methods (https://www.benthos.dev/docs/guides/bloblang/methods#ts_parse, etc) now return explicit timestamp values. Looks like we'd need to add an explicit method for creating a uint value.

[webfrank]

Hi, I just incur in a similar issue with this error:

Failed to send message to sql_insert: clickhouse [AppendRow]: sport clickhouse [AppendRow]: converting int64 to Int32 is unsupported Failed to send message to sql_insert: clickhouse [AppendRow]: packets clickhouse [AppendRow]: converting json.Number to Int64 is unsupported

Can be possible to have type conversion functions in bloblang?

[Jeffail]

Fixed with https://github.com/benthosdev/benthos/commit/2225bf849ba2637c3dba91708036e968b6bea99d

[packman80]

@Jeffail Thank you!