parsesql re-rendering foreign constrains incorrectly

[mjsir911]

Nim Version

Nim Compiler Version 2.2.4 [Linux: amd64]
Compiled at 2025-08-13
Copyright (c) 2006-2025 by Andreas Rumpf

active boot switches: -d:release -d:nimUseLinenoise

Description

Given the round trip:

FOREIGN KEY (artist_id_artist) REFERENCES artist(artist_id)

SqlNode(
  kind: nkForeignKey,
  sons: @[
    SqlNode(
      kind: nkIdent,
      strVal: "artist_id_artist"
    ),
    SqlNode(
      kind: nkReferences,
      sons: @[
      SqlNode(
        kind: nkCall,
        sons: @[
          SqlNode(
            kind: nkIdent,
            strVal: "artist"),
          SqlNode(
            kind: nkIdent,
            strVal: "artist_id"
          )]
      )]
    )
  ]
)

I'm then re-creating this with this code:

newNode(nkForeignKey, @[
  newNode(nkIdent, fk.columnName),
  newNode(nkReferences, @[
    newNode(nkCall, @[
      newNode(nkIdent, fk.referencedTable),
      newNode(nkIdent, fk.referencedColumn)
    ])
  ])
])

and I'm getting a (syntactically) incorrect:

FOREIGN KEY (artist_id_artist , REFERENCES artist(artist_id) )

(notice the extra comma)

here's the full code

import std/parsesql


let start = """
CREATE TABLE content(
  artist_id_artist integer,
  FOREIGN KEY (artist_id_artist) REFERENCES artist(artist_id)
)
"""

let ast = parseSql(start)

echo ast.treeRepr


# nkStmtList
#   nkCreateTable
#     nkIdent content
#     nkColumnDef
#       nkIdent artist_id_artist
#       nkIdent integer
#     nkForeignKey
#       nkIdent artist_id_artist
#       nkReferences
#         nkCall
#           nkIdent artist
#           nkIdent artist_id

let createdAst = 
  newNode(nkForeignKey, @[
    newNode(nkIdent, "artist_id_artist"),
    newNode(nkReferences, @[
      newNode(nkCall, @[
        newNode(nkIdent, "artist"),
        newNode(nkIdent, "artist_id")
      ])
    ])
  ])

let roundtrip = ast.renderSql(upperCase=true)
echo roundtrip
# CREATE TABLE content(artist_id_artist  integer , FOREIGN KEY (artist_id_artist , REFERENCES artist(artist_id) ) );;


let ending = createdAst.renderSql(upperCase=true)
echo ending
# FOREIGN KEY (artist_id_artist , REFERENCES artist(artist_id) )

Current Output

nkStmtList
  nkCreateTable
    nkIdent content
    nkColumnDef
      nkIdent artist_id_artist
      nkIdent integer
    nkForeignKey
      nkIdent artist_id_artist
      nkReferences
        nkCall
          nkIdent artist
          nkIdent artist_id

CREATE TABLE content(artist_id_artist  integer , FOREIGN KEY (artist_id_artist , REFERENCES artist(artist_id) ) );;
FOREIGN KEY (artist_id_artist , REFERENCES artist(artist_id) )

Expected Output

CREATE TABLE content(artist_id_artist  integer , FOREIGN KEY (artist_id_artist)  REFERENCES artist(artist_id) ) );;
FOREIGN KEY (artist_id_artist) REFERENCES artist(artist_id) )

Known Workarounds

unsure. I'm trying to figure out if this is valid sql or what. sqlite3 definitely doesn't take it, documented as much here: https://www.sqlite.org/syntax/table-constraint.html

let createdAst = 
  newNode(nkColumnDef, @[
    newNode(nkForeignKey),
    newNode(nkIdent, "artist_id_artist"),
    newNode(nkReferences, @[
      newNode(nkCall, @[
        newNode(nkIdent, "artist"),
        newNode(nkIdent, "artist_id")
      ])
    ])
  ])

using nkColumnDef (that I found from here)

Additional Information

No response

[mjsir911]

ah, the workaround doesn't do it because artist_id_artist isn't surrounded in parens

[Araq]

parsesql is now a Nimble package, report bugs over there please.