How can I append a source for a specific filetype

[SingularisArt]

How can I append to the table of sources based on filetypes? I'm currently using this:

local cmp = require("cmp")

local source_names = {
  nvim_lsp = "(LSP)",
  ultisnips = "(Snippets)",
  calc = "(Calc)",
  path = "(Path)",
  buffer = "(Buffer)",
  emoji = "(Emoji)",
  nvim_lsp_document_symbol = "(Symbols)",
  ["vim-dadbod-completion"] = "(SQL)",
}

local cmp_sources = {
  { name = "nvim_lsp" },
  { name = "ultisnips" },
  { name = "calc" },
  { name = "path" },
  { name = "buffer" },
  { name = "emoji" },
}

cmp.setup({
  snippet = {
    expand = function(args)
      vim.fn["UltiSnips#Anon"](args.body)
    end,
  },

  formatting = {
    fields = { "kind", "abbr", "menu" },

    format = function(entry, vim_item)
      local max_width = 50
      if max_width ~= 0 and #vim_item.abbr > max_width then
        vim_item.abbr = string.sub(vim_item.abbr, 1, max_width - 1) .. icons.ui.Ellipsis
      end

      vim_item.menu = ({
        omni = (vim.inspect(vim_item.menu):gsub("%\"", "")),
        buffer = "[Buffer]",
      })[entry.source.name]
      vim_item.kind = kind_icons[vim_item.kind]
      vim_item.menu = source_names[entry.source.name]
      vim_item.dup = duplicates[entry.source.name]
      return vim_item
    end,
  },
  sources = cmp_sources,
})

cmp.setup.filetype("sql", {
  sources = cmp.config.sources({
    { name = "vim-dadbod-completion" },
  }),
})

But when I open a sql file, I don't get any word suggestions or anything. It appears that all sources from above have been erased. What am I doing wrong?

[haininhhoang94]

I'm not sure if it is too late or not, but i'm pretty sure it is because this complete only work inside Buffer of Dadbod UI, like this pic