# Mimic the sqlite3 console shell's .dump command
# Author: Paul Kippes <[email protected]>

def _iterdump(connection):
"""
Returns an iterator to the dump of the database in an SQL text format.

Used to produce an SQL dump of the database. Useful to save an in-memory
database for later restoration. This function should not be called
directly but instead called from the Connection method, iterdump().
"""

cu = connection.cursor()
yield('BEGIN TRANSACTION;')

# sqlite_master table contains the SQL CREATE statements for the database.
q = """
SELECT name, type, sql
FROM sqlite_master
WHERE sql NOT NULL AND
type == 'table'
"""
schema_res = cu.execute(q)
for table_name, type, sql in schema_res.fetchall():
if table_name == 'sqlite_sequence':
yield('DELETE FROM sqlite_sequence;')
elif table_name == 'sqlite_stat1':
yield('ANALYZE sqlite_master;')
elif table_name.startswith('sqlite_'):
continue
# NOTE: Virtual table support not implemented
#elif sql.startswith('CREATE VIRTUAL TABLE'):
# qtable = table_name.replace("'", "''")
# yield("INSERT INTO sqlite_master(type,name,tbl_name,rootpage,sql)"\
# "VALUES('table','%s','%s',0,'%s');" %
# qtable,
# qtable,
# sql.replace("''"))
else:
yield('%s;' % sql)

# Build the insert statement for each row of the current table
res = cu.execute("PRAGMA table_info('%s')" % table_name)
column_names = [str(table_info[1]) for table_info in res.fetchall()]
q = "SELECT 'INSERT INTO \"%(tbl_name)s\" VALUES("
q += ",".join(["'||quote(" + col + ")||'" for col in column_names])
q += ")' FROM '%(tbl_name)s'"
query_res = cu.execute(q % {'tbl_name': table_name})
for row in query_res:
yield("%s;" % row[0])

# Now when the type is 'index', 'trigger', or 'view'
q = """
SELECT name, type, sql
FROM sqlite_master
WHERE sql NOT NULL AND
type IN ('index', 'trigger', 'view')
"""
schema_res = cu.execute(q)
for name, type, sql in schema_res.fetchall():
yield('%s;' % sql)

yield('COMMIT;')