Doesn't work with ddc.vim anymore

[dotdash]

The configuration syntax in the readme file seems to be outdated, and after changing it to:

call ddc#custom#patch_filetype(['sql', 'mysql', 'plsql'], #{ sources: ['dadbod-completion']})
call ddc#custom#patch_filetype(['sql', 'mysql', 'plsql'], #{
      \   sourceOptions: #{
      \     dadbod-completion: #{
      \       mark: 'DB',
      \       isVolatile: v:true,
      \     },
      \   },
      \ })

I get the following errors:

[ddc] 'source is too old: "dadbod-completion"'                                                                                                                                                                       
[ddc] 'source: dadbod-completion "gather()" failed'                                                                                                                                                                  
[ddc] 'source.gather is not a function'                                                                                                                                                                              
[ddc] 'TypeError: source.gather is not a function
    at callSourceGather (file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/ddc.ts:1336:34)
    at file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/ddc.ts:314:30
    at eventLoopTick (ext:core/01_core.js:169:7)
    at async Promise.all (index 0)
    at async Ddc.gatherResults (file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/ddc.ts:242:16)
    at async Ddc.doCompletion (file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/ddc.ts:580:34)
    at async _onEvent (file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/app.ts:310:5)
    at async file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/app.ts:204:11
    at async Lock.lock (https://deno.land/x/[email protected]/lock.ts:51:14)
    at async Object.onEvent (file:///home/xxx/.vim/plugged/ddc.vim/denops/ddc/app.ts:200:7)'