MySQL :: MySQL Connector/Python Developer Guide :: 10.5.8 MySQLCursor.executemany() Method (original) (raw)

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 sequenceseq_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, theINSERT 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 theoperation argument. Doing so raises anInternalError exception. Consider usingSection 9.3, “Executing Multiple Statements” instead.