# Mimic the sqlite3 console shell's .dump command

# Author: Paul Kippes <[email protected]>

# Every identifier in sql is quoted based on a comment in sqlite

# documentation "SQLite adds new keywords from time to time when it

# takes on new features. So to prevent your code from being broken by

# future enhancements, you should normally quote any identifier that

# is an English language word, even if you do not have to."

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'

ORDER BY "name"

"""

schema_res = cu.execute(q)

sqlite_sequence = []

for table_name, type, sql in schema_res.fetchall():

if table_name == 'sqlite_sequence':

rows = cu.execute('SELECT * FROM "sqlite_sequence";').fetchall()

sqlite_sequence = ['DELETE FROM "sqlite_sequence"']

sqlite_sequence += [

f'INSERT INTO "sqlite_sequence" VALUES(\'{row[0]}\',{row[1]})'

for row in rows

]

continue

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','{0}','{0}',0,'{1}');".format(

# qtable,

# sql.replace("''")))

else:

yield('{0};'.format(sql))

# Build the insert statement for each row of the current table

table_name_ident = table_name.replace('"', '""')

res = cu.execute('PRAGMA table_info("{0}")'.format(table_name_ident))

column_names = [str(table_info[1]) for table_info in res.fetchall()]

q = """SELECT 'INSERT INTO "{0}" VALUES({1})' FROM "{0}";""".format(

table_name_ident,

",".join("""'||quote("{0}")||'""".format(col.replace('"', '""')) for col in column_names))

query_res = cu.execute(q)

for row in query_res:

yield("{0};".format(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('{0};'.format(sql))

# gh-79009: Yield statements concerning the sqlite_sequence table at the

# end of the transaction.

for row in sqlite_sequence:

yield('{0};'.format(row))

yield('COMMIT;')