In This Package:

desc.py

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"""
Introspect the table descriptions in the DB ...
for schema checking comparisons against 
what the Spec/Code expects :
this is step zero in handling schema migration.


{'Extra': '', 'Default': '0', 'Field': 'SEQNO', 'Key': 'PRI', 'Null': 'NO', 'Type': 'int(11)'}
{'Extra': '', 'Default': '0', 'Field': 'ROW_COUNTER', 'Key': 'PRI', 'Null': 'NO', 'Type': 'int(11)'}
{'Extra': '', 'Default': '', 'Field': 'channelId', 'Key': '', 'Null': 'YES', 'Type': 'int(10) unsigned'}
{'Extra': '', 'Default': '', 'Field': 'status', 'Key': '', 'Null': 'YES', 'Type': 'int(10) unsigned'}
{'Extra': '', 'Default': '', 'Field': 'pedestalHigh', 'Key': '', 'Null': 'YES', 'Type': 'double'}
{'Extra': '', 'Default': '', 'Field': 'sigmaPedestalHigh', 'Key': '', 'Null': 'YES', 'Type': 'double'}
{'Extra': '', 'Default': '', 'Field': 'pedestalLow', 'Key': '', 'Null': 'YES', 'Type': 'double'}
{'Extra': '', 'Default': '', 'Field': 'sigmaPedestalLow', 'Key': '', 'Null': 'YES', 'Type': 'double'}
{'Extra': '', 'Default': '', 'Field': 'thresholdHigh', 'Key': '', 'Null': 'YES', 'Type': 'double'}
{'Extra': '', 'Default': '', 'Field': 'thresholdLow', 'Key': '', 'Null': 'YES', 'Type': 'double'}


"""
import os
os.environ.setdefault("DBCONF","tmp_offline_db")
from DybDbi import gDbi

class Result(list):
    """
    Perform low-level MySQL query against DB number dbno in the cascade
    and store result as a list of dicts.

    NB no type conversions are applied, everything stays as strings.  
    """
    def __init__(self, sql , dbno=0):
        list.__init__(self)
        stm = gDbi.cascader.CreateStatement(dbno)   
        tss = stm.ExecuteQuery(sql)
        nf = tss.GetNumFields()
        while tss.NextResultRow():
            d = dict( [(tss.GetFieldName(n),tss.GetString(n)) for n in range(nf)] )
            self.append(d)

    def __str__(self):
        return "\n".join( [repr(d) for d in self])

if __name__=='__main__':

    ## output descriptions of all tables 
    tabs = Result("show tables")
    for t in map(lambda d:d.values()[0],tabs):
        print "\ntable %s " % t 
        dsc = Result("describe %s" % t )
        print dsc

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