python sqlite3, inserting row into table using data from another table

Question

There are many eaxmples of this, but in all cases that I saw they knew the names of the fields(columns). The two tables have exactly the same column/fields.

My solution has solved my current problem but as you can see from the code, it might qualify for the 'most ridiculous code of the year' award.

# Copy data from one table to another in the same database
print '-' * 70
print 'Copy data from one table to another in the same database\n'
print '  Usefull for creating test data.'
print '-' * 70

import sqlite3

connection = sqlite3.connect("table.sqlite")
cursor = connection.cursor()

source_table = 'table1'
target_table = 'test_table1'

stmt = "SELECT * FROM %s" % source_table

cursor.execute(stmt)
data = cursor.fetchall()

for row in data:
    stmt = "insert into %s values " % target_table + str(row)
    stmt = stmt.replace("u'", '"')
    stmt = stmt.replace("'", '"')
    stmt = stmt.replace(' None', ' Null')
    cursor.execute(stmt)
    connection.commit()

connection.close()

There must be a better (more reliable) way to do this.

Answer 1

Use cursor.executemany :

import sqlite3

connection = sqlite3.connect("table.sqlite")
cursor = connection.cursor()

source_table = 'table1'
target_table = 'test_table1'

stmt = "SELECT * FROM %s" % source_table

cursor.execute(stmt)
data = cursor.fetchall()

fields = ','.join('?' for desc in cursor.description)
stmt = "insert into {} values ({})".format(target_table, fields)
cursor.executemany(stmt, data)
connection.commit()
connection.close()

Used cursor.description to get column data.

NOTE

parameter marks vary according to database module. sqlite3 module use qmark( ? ). You should check it if you use another database module.