django create model of unknown table dynamically

Question

I need to create models of existing previously unknown tables. Others have had said to

You can look at inspectdb code, and instead of outputting code return classes.

but for a python newbie I am having difficulties. Could anyone offer a more concrete example on how to do this? Many thanks.

UPDATE: I am exploring this. Looks v promising. There seem to be several options for creating dynamic models, some of which though require non- mySQL dbs (see this stackoverflow Q)

UPDATE2: I can now create a model of a previously unknown mysql table at runtime using the below functions. When I try to query the model though, for a table called 'table1' I get "Table 'djangodb.subscription_table1' doesn't exist"). When I rename 'table1' to 'subscription_table1' I get this error: "Table 'djangodb.subscription_subscription_tb2f1e1e47d73417ab2b187bc4a08bf57' doesn't exist").

HELP!

FINAL UPDATE: I went with another solution for my particular problem: Django - List of Dictionaries to Tables2

def getModel(table_name):
    myColumns=getColumns(table_name)


    attrs = {}
    attrs['__module__']  = 'subscription.models'

    for x,y in myColumns.items():
        fieldType = y["type"]
        if x == 'id': ''
        elif   fieldType  == "char":    attrs[x]=models.CharField(max_length='length')
        elif fieldType  == "float":   attrs[x]=models.FloatField(max_length='length')   
        elif fieldType  == "int":     attrs[x]=models.IntegerField()
        elif fieldType  == "text":    attrs[x]=models.TextField()
        else: print "AW PROB in exptDB---------------",x,y["type"],y["length"] 

    myModel = type(str(table_name), (models.Model,), attrs) 



    return myModel




def getColumns(expt_id):
    cursor = connection.cursor()
    cursor.execute("desc %s;" % (expt_id))
    exptInfo = str(cursor.fetchall())[1:-1]

    myList= exptInfo.split("""(u'""")
    myColumns = {}
    for item in myList:
        mySplit = item.replace("u'","").replace("'","").replace(" ","").split(",")
        if len(mySplit)>=2:  
            subSplit=mySplit[1].split("(")
            if len(subSplit)>=1: 
                subSplit.append('999')#does not latter.  
                myColumns[mySplit[0]]={"type":subSplit[0],"length":subSplit[1].replace(")","")}

    return myColumns

"Previously unknown tables" - what does that mean? – Abid A Jan 19 '13 at 18:05 — Abid A, Jan 19 '13 at 18:05
A table that does not have a model – andyw Jan 19 '13 at 21:36 — andyw, Jan 19 '13 at 21:36

score 0 · Answer 1 · answered Jan 20 '13 at 16:45

0

You want to use the inspectdb command. It's designed precisely for this kind of situation.

However, you don't need to look at the inspectdb code, just read the following page dedicated to this issue: https://docs.djangoproject.com/en/dev/howto/legacy-databases/

answered Jan 20 '13 at 16:45

Abid A

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I need to create these models at runtime unforunately, for pre-existing but unknown mysql tables. – andyw Jan 21 '13 at 12:30

django create model of unknown table dynamically

1 Answers1