mysqlparse

A highly experimental attempt to have a sane parser library to parse MySQL statements.

At the moment - use it at your own risk!

Features

• Parses SOME SQL strings.

Example

Some properties that can be accessed.

>>> import mysqlparse
>>> sql = mysqlparse.parse("""
...     ALTER TABLE `django_user` ADD COLUMN `notes` LONGTEXT NOT NULL
... """)
>>> print(sql.statements[0].statement_type)
ALTER
>>> print(sql.statements[0].table_name)
`django_user`
>>> print(sql.statements[0].ignore)
False
>>> print(sql.statements[0].alter_specification[0].alter_action)
ADD COLUMN
>>> print(sql.statements[0].alter_specification[0].column_name)
`notes`
>>> print(sql.statements[0].alter_specification[0].data_type)
LONGTEXT
>>> print(sql.statements[0].alter_specification[0].null)
False
>>> print(sql.statements[0].alter_specification[0].column_position)
LAST

Checking that the alter statement is backwards compatible with a previous version of SOME code, which does not know how to save notes as NOT NULL:

for statement in sql.statements:
    if statement != 'ALTER':
        continue
    for column in statement.alter_specification:
        if column.data_type == 'LONGTEXT':
            if column.null is False and column.default != 'NULL':
                print "{s.table_name}.{c.column_name} is `LONGTEXT NOT NULL` which may break the production system. Use `LONGTEXT DEFAULT NULL` instead.".format(
                    s=statement,
                    c=column,
                )

How can you help?

A short list of things that would help (from relatively easiest):

• Raise an issue with an edge case statement that should parse, but doesn't.
• Raise an issue with how you would like to use this library.
• Document the available properties in the parsed object.
• Add a missing test case or suggest a way to avoid so much repetition in tests checking the same statement, but with variations.
• Suggest how to use pyparsing to do statement validation.
• Maybe it is possible to generate pyparsing parser from the MySQL source code?
• Add ability to unparse the parse (sub)trees back into valid SQL.

Why?

Out of frustration for lack of a better tool.