python/lib/Lib/isql.py

# $Id: isql.py 6639 2009-08-10 17:06:51Z fwierzbicki $

import dbexts, cmd, sys, os

"""
Isql works in conjunction with dbexts to provide an interactive environment
for database work.
"""

__version__ = "$Revision: 6639 $"[11:-2]

class IsqlExit(Exception): pass

class Prompt:
    """
    This class fixes a problem with the cmd.Cmd class since it uses an ivar 'prompt'
    as opposed to a method 'prompt()'.  To get around this, this class is plugged in
    as a 'prompt' attribute and when invoked the '__str__' method is called which
    figures out the appropriate prompt to display.  I still think, even though this
    is clever, the attribute version of 'prompt' is poor design.
    """
    def __init__(self, isql):
        self.isql = isql
    def __str__(self):
        prompt = "%s> " % (self.isql.db.dbname)
        if len(self.isql.sqlbuffer) > 0:
            prompt = "... "
        return prompt
    if os.name == 'java':
        def __tojava__(self, cls):
            import java.lang.String
            if cls == java.lang.String:
                return self.__str__()
            return False

class IsqlCmd(cmd.Cmd):

    def __init__(self, db=None, delimiter=";", comment=('#', '--')):
        cmd.Cmd.__init__(self, completekey=None)
        if db is None or type(db) == type(""):
            self.db = dbexts.dbexts(db)
        else:
            self.db = db
        self.kw = {}
        self.sqlbuffer = []
        self.comment = comment
        self.delimiter = delimiter
        self.prompt = Prompt(self)

    def parseline(self, line):
        command, arg, line = cmd.Cmd.parseline(self, line)
        if command and command <> "EOF":
            command = command.lower()
        return command, arg, line

    def do_which(self, arg):
        """\nPrints the current db connection parameters.\n"""
        print self.db
        return False

    def do_EOF(self, arg):
        return False

    def do_p(self, arg):
        """\nExecute a python expression.\n"""
        try:
            exec arg.strip() in globals()
        except:
            print sys.exc_info()[1]
        return False

    def do_column(self, arg):
        """\nInstructions for column display.\n"""
        return False

    def do_use(self, arg):
        """\nUse a new database connection.\n"""
        # this allows custom dbexts
        self.db = self.db.__class__(arg.strip())
        return False

    def do_table(self, arg):
        """\nPrints table meta-data.  If no table name, prints all tables.\n"""
        if len(arg.strip()):
            self.db.table(arg, **self.kw)
        else:
            self.db.table(None, **self.kw)
        return False

    def do_proc(self, arg):
        """\nPrints store procedure meta-data.\n"""
        if len(arg.strip()):
            self.db.proc(arg, **self.kw)
        else:
            self.db.proc(None, **self.kw)
        return False

    def do_schema(self, arg):
        """\nPrints schema information.\n"""
        print
        self.db.schema(arg)
        print
        return False

    def do_delimiter(self, arg):
        """\nChange the delimiter.\n"""
        delimiter = arg.strip()
        if len(delimiter) > 0:
            self.delimiter = delimiter

    def do_o(self, arg):
        """\nSet the output.\n"""
        if not arg:
            fp = self.db.out
            try:
                if fp:
                    fp.close()
            finally:
                self.db.out = None
        else:
            fp = open(arg, "w")
            self.db.out = fp

    def do_q(self, arg):
        """\nQuit.\n"""
        try:
            if self.db.out:
                self.db.out.close()
        finally:
            return True

    def do_set(self, arg):
        """\nSet a parameter. Some examples:\n set owner = 'informix'\n set types = ['VIEW', 'TABLE']\nThe right hand side is evaluated using `eval()`\n"""
        if len(arg.strip()) == 0:
            items = self.kw.items()
            if len(items):
                print
                # format the results but don't include how many rows affected
                for a in dbexts.console(items, ("key", "value"))[:-1]:
                    print a
                print
            return False
        d = filter(lambda x: len(x) > 0, map(lambda x: x.strip(), arg.split("=")))
        if len(d) == 1:
            if self.kw.has_key(d[0]):
                del self.kw[d[0]]
        else:
            self.kw[d[0]] = eval(d[1])

    def do_i(self, arg):
        fp = open(arg)
        try:
            print
            for line in fp.readlines():
                line = self.precmd(line)
                stop = self.onecmd(line)
                stop = self.postcmd(stop, line)
        finally:
            fp.close()
        return False

    def default(self, arg):
        try:
            token = arg.strip()
            if not token:
                return False
            comment = [token.startswith(x) for x in self.comment]
            if reduce(lambda x,y: x or y, comment):
                return False
            if token[0] == '\\':
                token = token[1:]
            # is it possible the line contains the delimiter
            if len(token) >= len(self.delimiter):
                # does the line end with the delimiter
                if token[-1 * len(self.delimiter):] == self.delimiter:
                    # now add all up to the delimiter
                    self.sqlbuffer.append(token[:-1 * len(self.delimiter)])
                    if self.sqlbuffer:
                        q = " ".join(self.sqlbuffer)
                        print q
                        self.db.isql(q, **self.kw)
                        self.sqlbuffer = []
                        if self.db.updatecount:
                            print
                            if self.db.updatecount == 1:
                                print "1 row affected"
                            else:
                                print "%d rows affected" % (self.db.updatecount)
                            print
                        return False
            if token:
                self.sqlbuffer.append(token)
        except:
            self.sqlbuffer = []
            print
            print sys.exc_info()[1]
            print
        return False

    def emptyline(self):
        return False

    def postloop(self):
        raise IsqlExit()

    def cmdloop(self, intro=None):
        while 1:
            try:
                cmd.Cmd.cmdloop(self, intro)
            except IsqlExit, e:
                break
            except Exception, e:
                print
                print e
                print
            intro = None

if __name__ == '__main__':
    import getopt

    try:
        opts, args = getopt.getopt(sys.argv[1:], "b:", [])
    except getopt.error, msg:
        print
        print msg
        print "Try `%s --help` for more information." % (sys.argv[0])
        sys.exit(0)

    dbname = None
    for opt, arg in opts:
        if opt == '-b':
            dbname = arg

    intro = "\nisql - interactive sql (%s)\n" % (__version__)

    isql = IsqlCmd(dbname)
    isql.cmdloop()