def get_table_columns(conn,obj):
"""
Obtiene las columnas de una tabla
"""
cur = conn.cursor()
cur.execute("""
SELECT a.attname,
pg_catalog.format_type(a.atttypid, a.atttypmod),
(SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) as format_extra,
a.attnotnull, a.attnum
FROM pg_catalog.pg_attribute a
WHERE a.attrelid = %s AND a.attnum > 0 AND NOT a.attisdropped
ORDER BY a.attnum
""", [obj.oid])
for name, format_type, format_extra, notnull, number in cur:
field = Struct()
field.name = name
field.format_type = format_type
field.format_extra = format_extra
field.default = None # <- probablemente esta en format_extra...
field.notnull = notnull
field.nullable = not field.notnull
field.sql_nullable = "NOT NULL" if notnull else ""
field.number = number
yield field
