junyang / radb Goto Github PK

I'm using radb version 3.0.2 with Python 3.7.4 from Anaconda 3, on macOS Mojave 10.14.6.

When I run the \help; command at the ra> prompt, I get what appears to be a parsing error: ERROR: line 1:0 token recognition error at: '\h'. Here is the full context:

$ radb beers.db
WARNING: unable to read configuration file /Users/Foobar/.radb.ini; resorting to system defaults
radb: A relational algebra interpreter over relational databases
Version 3.0.2 by Jun Yang <[email protected]>
https://github.com/junyang/radb
ra> \list;
database relations:
  Bar(name:string, address:string)
  Beer(name:string, brewer:string)
  Drinker(name:string, address:string)
  Frequents(drinker:string, bar:string, times_a_week:number)
  Likes(drinker:string, beer:string)
  Serves(bar:string, beer:string, price:number)
ra> \help;
ERROR: line 1:0 token recognition error at: '\h'
ra> \quit;
$

I have the following code:

import radb.parse dd = {} dd["Person"] = {"name": "string", "age": "integer", "gender": "string"} dd["Eats"] = {"name": "string", "pizza": "string"} stmt = """\project_{Person.name, Eats.pizza} \select_{Person.name = Eats.name}(Person \cross Eats);""" ra = radb.parse.one_statement_from_string(stmt) print(ra)

It shows me the following error
Traceback (most recent call last):
File "test.py", line 9, in
ra = one_statement_from_string(stmt)
File "/home/alajeb/.local/lib/python3.6/site-packages/radb/parse.py", line 262, in one_statement_from_string
ast = ASTBuilder().visit(tree)
File "/home/alajeb/.local/lib/python3.6/site-packages/antlr4/tree/Tree.py", line 34, in visit
return tree.accept(self)
File "/home/alajeb/.local/lib/python3.6/site-packages/radb/RAParser.py", line 1745, in accept
return visitor.visitStatement(self)
File "/home/alajeb/.local/lib/python3.6/site-packages/radb/parse.py", line 247, in visitStatement
return self.visit(ctx.getChild(0))
File "/home/alajeb/.local/lib/python3.6/site-packages/antlr4/tree/Tree.py", line 34, in visit
return tree.accept(self)
File "/home/alajeb/.local/lib/python3.6/site-packages/radb/RAParser.py", line 972, in accept
return visitor.visitProjectExpr(self)
File "/home/alajeb/.local/lib/python3.6/site-packages/radb/parse.py", line 175, in visitProjectExpr
return radb.ast.Project(self.visit(ctx.listOfValExprs()), self.visit(ctx.relExpr()))
AttributeError: module 'radb' has no attribute 'ast'

After a fresh install of radb, the beers example cannot be started:

[cloudera@quickstart ~]$ /usr/local/bin/python3.6 --version
Python 3.6.5
[cloudera@quickstart ~]$ ls beers.ra
beers.ra
[cloudera@quickstart ~]$ radb -i beers.ra beers.db
WARNING: unable to read configuration file /home/cloudera/.radb.ini; resorting to system defaults
ERROR: failed to connect to database: No module named '_sqlite3'

I thought sqlite3 would have been bundled with radb.

It seems I cannot parse the rename operator from string. The rename-statement to be parsed is a snippet from the documentation.

radb.parse.one_statement_from_string('\rename_{s2} (Serves);')
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/antlr4/Lexer.py", line 128, in nextToken
ttype = self._interp.match(self._input, self._mode)
File "/usr/lib/python3.6/site-packages/antlr4/atn/LexerATNSimulator.py", line 99, in match
return self.execATN(input, dfa.s0)
File "/usr/lib/python3.6/site-packages/antlr4/atn/LexerATNSimulator.py", line 191, in execATN
return self.failOrAccept(self.prevAccept, input, s.configs, t)
File "/usr/lib/python3.6/site-packages/antlr4/atn/LexerATNSimulator.py", line 250, in failOrAccept
raise LexerNoViableAltException(self.recog, input, self.startIndex, reach)
antlr4.error.Errors.LexerNoViableAltException: LexerNoViableAltException('{')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python3.6/site-packages/radb/parse.py", line 252, in one_statement_from_string
tree = parser.statement()
File "/usr/lib/python3.6/site-packages/radb/RAParser.py", line 1673, in statement
la_ = self._interp.adaptivePredict(self._input,18,self._ctx)
File "/usr/lib/python3.6/site-packages/antlr4/atn/ParserATNSimulator.py", line 342, in adaptivePredict
alt = self.execATN(dfa, s0, input, index, outerContext)
File "/usr/lib/python3.6/site-packages/antlr4/atn/ParserATNSimulator.py", line 465, in execATN
input.consume()
File "/usr/lib/python3.6/site-packages/antlr4/BufferedTokenStream.py", line 99, in consume
if self.sync(self.index + 1):
File "/usr/lib/python3.6/site-packages/antlr4/BufferedTokenStream.py", line 111, in sync
fetched = self.fetch(n)
File "/usr/lib/python3.6/site-packages/antlr4/BufferedTokenStream.py", line 123, in fetch
t = self.tokenSource.nextToken()
File "/usr/lib/python3.6/site-packages/antlr4/Lexer.py", line 130, in nextToken
self.notifyListeners(e) # report error
File "/usr/lib/python3.6/site-packages/antlr4/Lexer.py", line 285, in notifyListeners
listener.syntaxError(self, None, self._tokenStartLine, self._tokenStartColumn, msg, e)
File "/usr/lib/python3.6/site-packages/antlr4/error/ErrorListener.py", line 60, in syntaxError
delegate.syntaxError(recognizer, offendingSymbol, line, column, msg, e)
File "/usr/lib/python3.6/site-packages/radb/parse.py", line 75, in syntaxError
raise ParsingError('line {}:{} {}'.format(line, column, msg))
radb.parse.ParsingError: line 1:7 token recognition error at: '{'

We'd love to use radb for our database course at RWTH Aachen i5.
It would be great if it would be possible to interact with radb without a command line so that the integration
with our jupyter notebooks can be improved.

For a start i suggest it would be great to start with a test-first approach and add some python unit tests to the project. This way you could e.g. also automatically test the project with a continuous integration approach.

SQLAlchemy recently released 2.0.0 which radb doesn't work with. The latest version that works:

SQLAlchemy==1.4.46

Installing radb will install the latest version by default, so you may need to downgrade SQLAlchemy to 1.4.46 after installation.