10.5.8 MySQLCursor.executemany() Method

Syntax:

cursor.executemany(operation, seq_of_params)

This method prepares a database operation (query or command) and executes it against all parameter sequences or mappings found in the sequence seq_of_params.

Note

In Python, a tuple containing a single value must include a comma. For example, ('abc') is evaluated as a scalar while ('abc',) is evaluated as a tuple.

In most cases, the executemany() method iterates through the sequence of parameters, each time passing the current parameters to the execute() method.

An optimization is applied for inserts: The data values given by the parameter sequences are batched using multiple-row syntax. The following example inserts three records:

data = [
  ('Jane', date(2005, 2, 12)),
  ('Joe', date(2006, 5, 23)),
  ('John', date(2010, 10, 3)),
]
stmt = "INSERT INTO employees (first_name, hire_date) VALUES (%s, %s)"
cursor.executemany(stmt, data)

For the preceding example, the INSERT statement sent to MySQL is:

INSERT INTO employees (first_name, hire_date)
VALUES ('Jane', '2005-02-12'), ('Joe', '2006-05-23'), ('John', '2010-10-03')

With the executemany() method, it is not possible to specify multiple statements to execute in the operation argument. Doing so raises an InternalError exception. Consider using Section 9.3, “Executing Multiple Statements” instead.