In This Package:

dbcmd.py

Go to the documentation of this file.

import os
from dbconf import DBConf


class CommandLine(dict):
    """
    Base class for composing and invoking command lines in a separate process 
    """
    def _exepath(self):
        for cmd in self._exenames:
            which = os.popen("which %s" % cmd).read().rstrip("\n")
            if os.path.exists(which):
                return which
        return None
    exepath = property( _exepath )
    cmd      = property( lambda self:self._cmd % self )
    cmd_nopw = property( lambda self:self._cmd % dict(self, password="***") )

    def __init__(self, *args, **kwa ):
        dict.__init__(self, *args, **kwa )
        exe = self.exepath
        assert exe, "cannot find executable %r check your PATH " % self._exenames
        self.update( exepath=exe, path="/dev/null", argline="" )

    def __str__(self):
        return "%s %s " % (self.__class__.__name__, self.cmd_nopw )

    def __call__(self, verbose=False):
        if verbose:
            print self
        return os.popen(self.cmd).read()        


class MySQLLoad(CommandLine):
    """
    Wrapper around sql loading commandline that hooks up to the 
    config parameters from the :file:`~/.my.cnf` 
    """
    _exenames = ['mysql','mysql5']
    _cmd = "cat %(path)s | %(exepath)s --no-defaults --host=%(host)s --user=%(user)s --password=%(password)s %(database)s  "
 
    def __call__(self, path, verbose=True ):
        """Arguments are used to update the tables list and dumppath """
        assert os.path.exists(path),  "MySQLLoad ERROR no mysqldump file at %s " % path
        assert self['database'].startswith('tmp_'), "MySQLLoad error invalid database name %r " % self 
        self.update( path=path )
        return CommandLine.__call__(self, verbose=verbose) 


class MySQLDumpT(CommandLine):
    """
    Try the mysqldump -T/tmp  option 
        the specified directory must exist and be writable 

        surprised to find that this worked ...with G connected to C
        and writing into /tmp on G 

    """
    _exenames = ['mysqldump','mysqldump5']
    _cmd = "time %(exepath)s --no-defaults --skip-opt --host=%(host)s --user=%(user)s --password=%(password)s  -T%(tdir)s %(database)s "
    
    def __call__(self, tdir, verbose=True ):
        """Arguments are used to update the tables list and dumppath """
        self.update( tdir=tdir )
        return CommandLine.__call__(self, verbose=verbose)
 

class MySQLImport(CommandLine):
    """
    http://dev.mysql.com/doc/refman/5.0/en/mysqlimport.html

    `no-defaults` must be the first option
    `local` option needed, otherwise mysqlimport: Error: Can't get stat of ...
    the table must be pre-existing, otherwise  'tmp_offline_db.SimPmtSpecVld' doesn't exist, when using table: SimPmtSpecVld

    a bad import leads to NULLified rows
        0       0000-00-00 00:00:00     0000-00-00 00:00:00     NULL    NULL    NULL    NULL    NULL    0000-00-00 00:00:00     0000-00-00 00:00:00

    """
    _exenames = ['mysqlimport','mysqlimport5']
    _cmd = '%(exepath)s --no-defaults --local --host=%(host)s --user=%(user)s --password=%(password)s  --fields-optionally-enclosed-by="\\"" --fields-terminated-by=, --ignore-lines=1   %(database)s %(tabfile)s '
    def __call__(self, tabfile , verbose=True ):
        self.update(tabfile=tabfile ) 
        return CommandLine.__call__(self, verbose=verbose)


class MySQLDump(CommandLine):
    """
    Wrapper around a mysqldump command line that integrates 
    config parameters from the :file:`~/.my.cnf` with table list and
    dumppath call arguments.
  
    For background on mysqldump see http://dev.mysql.com/doc/refman/5.0/en/mysqldump.html

    Options used with  the mysqldump command  includes `--no-defaults` which   
    ensures the command is fully controlled by this script and does not depend on 
    users defaults. Also the `--skip-opt` is used to avoid an error when used by 
    with mysql identities without LOCK TABLES privilege::
  
        mysqldump: Got error: 1044: Access denied for user 'dayabay'@'%' to database 'offline_db' when doing LOCK TABLES

    """
    _exenames = ['mysqldump','mysqldump5']
    _cmd = "time %(exepath)s --no-defaults --skip-opt --host=%(host)s --user=%(user)s --password=%(password)s %(database)s %(argline)s > %(path)s "
    
    def __call__(self, tables, dumppath , verbose=True ):
        """Arguments are used to update the tables list and dumppath """
        self.update( argline=" ".join(tables), path=dumppath )
        return CommandLine.__call__(self, verbose=verbose)



if __name__ == '__main__':
    cnf = DBConf("tmp_offline_db")
    imp = MySQLImport(cnf)
    #tmpd = "/tmp/tmpRjHVN9"    
    tmpd = "/tmp"

    imp( tabfile=os.path.join(tmpd, "rdumpcat/SimPmtSpec/SimPmtSpecVld.csv") , verbose=True )
 

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