junyang / radb Goto Github PK

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.

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: '{'

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'

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.

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.

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;
$