[sqlite] Can you get a description of a table when the sql results are empty?

[Scott Chapman]

I made a little python code below that fetches a sqlite3 table description 
(using apsw) but it won't work when the table is empty. ÂI made it tell me 
the table is empty in this case. Â

Is there a way to get the columns in a table without having to parse the SQL 
that created the table, when the table is empty?

import re
import sys
import apsw
db = apsw.Connection(sys.argv[1])
cursor = db.cursor()
print
sql="select tbl_name from sqlite_master where type='table'"
cursor.execute(sql)
tables=[]
while True:
  try:
    db_row=cursor.next()
  except StopIteration:
    break
  tables.append(db_row)
print "Tables:"
for table_name in tables:
 print table_name[0]
 print
 table_name=table_name[0]
 print "========================================================"
 print "table name: %s" % table_name
 print    Â
 # Get the sql that created table and parse it to determine which is the 
primary key.
 # I don't know of any other way to determine the primary key in sqlite3.
 sql="select sql from sqlite_master where tbl_name='%s';" % table_name
 cursor.execute(sql)
 create_table_sql=cursor.next()[0]
 print "Creation SQL: %s" % create_table_sql
 print
 match=re.search(r'.*[ (](.*?) integer primary 
key',create_table_sql,re.IGNORECASE)
 if match:
   pkey_column = match.group(1)
   print "Primary key: %s" % pkey_column
   print
 
 # Get a row from the table so I can determine the description
 sql="select oid,* from %s limit 1" % table_name
 cursor.execute (sql)
     
 # Get the column names and make the HTML <table> header row
 try:
   cdes=cursor.getdescription()
 except apsw.ExecutionCompleteError:
   # HERE's where I'd like to be able to go ahead and get the description!
   print 'table: %s is empty!' % table_name Â
 else:
   print "Columns in table %s:" % table_name
   for header,dummy in cdes[1:]:
     print ' Â%s: %s' % (header,dummy)

Scott