pysqlite - Checking the existance of a table

[rh0dium]

Hi all,

I am starting to play with pysqlite, and would like to know if there is
a function to determine if a table exists or not.
Thanks

[Matthias Kluwe]

Simply use the internal table SQLite_Master:

select name from SQLite_Master

will return all existing tables.

Regards,
Matthias

[Cousin Stanley]

| I am starting to play with pysqlite,
| and would like to know if there is a function
| to determine if a table exists or not.

rh0dium ....

One way to get at a list of table names
in an SQLite data base is to query
the sqlite_master table ....
import sys
import sqlite

this_db = sys.argv[ 1 ]

list_sql = [ "select tbl_name" ,
"from sqlite_master" ]

str_sql = '\n'.join( list_sql )

dbc = sqlite.connect( db = "%s" % this_db )

curs = dbc.cursor()

curs.execute( str_sql )

list_tables = curs.fetchall()

print '\n Table Names in SQLite DB .... %s \n' % ( this_db )

for table_name in list_tables :

print " %s " % ( table_name )

print

dbc.close()
--
Stanley C. Kitching
Human Being
Phoenix, Arizona

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[Gerhard Häring]

rh0dium wrote:

Hi all,

I am starting to play with pysqlite, and would like to know if there is
a function to determine if a table exists or not.

You can try to access the table in a try-catch block, something like:

cur.execute("select * from tablename where 1=2")

and check if it fails.

Or you can query the sqlite_master table (don't know any specification
off-hand, but it contains the schema information).

Instead of doing a select on sqlite_master, you can use "pragma
table_info", which returns information for each column in the table,
and, apparently, an empty list if the table does not exist:

cur.execute("pragma table_info(foo)")
print cur.fetchall() [(0, u'bar', u'integer', 0, None, 0)]
cur.execute("pragma table_info(foo_does_not_exist)")
print cur.fetchall()

[]

HTH,

-- Gerhard

[Peter Hansen]

Gerhard Häring wrote:

Or you can query the sqlite_master table (don't know any specification
off-hand, but it contains the schema information).

Item #9 in the FAQ (http://www.sqlite.org/faq.html#q9) shows it as:

CREATE TABLE sqlite_master (
type TEXT,
name TEXT,
tbl_name TEXT,
rootpage INTEGER,
sql TEXT
);
-Peter