Running a .sql file after migrations in django

Question

I have setup my migrations in django (very small project); but I have a .sql file that has a bunch of data I need in the database.

What is the best way (or is it even possible) to have this .sql file executed after/during running migrations?

The sql file just contains an insert of the data like so:

INSERT INTO `mileages_mileages` (`id`, `miles`, `start_location`, `end_location`) VALUES
(NULL,3, 'Location 1', 'Location 2'),

I just need to execute that .sql file after running the initial migrations of my models.

Is that possible?

Answer 1

migrations.RunSQL()

Does not accept a file as input. Only raw SQL. To solve this you need to use either:

migrations.RunSQL(
    """
    INSERT INTO 'mileages_mileages' ('id', 'miles', 'start_location', 'end_location') 
    VALUES
       (NULL,3, 'Location 1', 'Location 2');
    """)

or

def load_data_from_sql(apps, schema_editor):
   file_path = os.path.join(os.path.dirname(__file__), 'file_name.sql')
   sql_statement = open(file_path).read()
   with connection.cursor() as c:
       c.execute(sql_statement)

class Migration(migrations.Migration):
    dependencies = [
        ('..', '...'),
    ]

    operations = [
        migrations.RunPython(load_data_from_sql),
    ]

Answer 2

Here is the full script(not perfect, but as is) for converting MySQL statements with DELIMITER to SQL execution.

Information about multiply delimiters in SQL statement https://stackoverflow.com/a/52292690/9521312

Add script execution in migration file

There are both examples of using script: run sql file or run raw MySQL statement

from anywhere import migrate_run_sql

operations = [
              migrations.RunPython(migrate_run_sql.run_sql_file('contract_triggers.sql')),
              migrations.RunPython(migrate_run_sql.run_sql(
                                                           """
                                                           DELIMITER $$
                                                           CREATE TRIGGER trigger_name BEFORE INSERT ON table
                                                           FOR EACH ROW
                                                           BEGIN
                                                             IF NEW.number <> 'anynumber' AND NEW.number <> 'anynumber'
                                                               THEN
                                                                 SET NEW.number = 'anynumber';
                                                             END IF;
                                                           END$$
                                                           """
                                                           ))
             ]

Script file

# -*- coding: utf-8 -*-
from django.db import connection
import re
from StringIO import StringIO
from django.conf import settings
import os

# this function get raw MySQL statement
def run_sql(sql): 
    def load_data_from_sql(app, schema_editor):
        f = StringIO(sql)
        return _runsql(f)

    return load_data_from_sql

# this function get sql file
def run_sql_file(filename):
    def load_data_from_sql(app, schema_editor):
        filepath = os.path.join(settings.PROJECT_PATH, '../deploy/mysql/', filename)
        with open(filepath, 'rb') as f:
            return _runsql(f)

    return load_data_from_sql

# in this function content splits and checks line by line
def _runsql(f):
    with connection.cursor() as c:
        file_data = f.readlines()
        statement = ''
        delimiter = ';\n'
        for line in file_data:
            if re.findall('DELIMITER', line): # found delimiter
                if re.findall('^\s*DELIMITER\s+(\S+)\s*$', line):
                    delimiter = re.findall('^\s*DELIMITER\s+(\S+)\s*$', line)[0] + '\n'
                    continue
                else:
                    raise SyntaxError('Your usage of DELIMITER is not correct, go and fix it!')
            statement += line # add lines while not met lines with current delimiter
            if line.endswith(delimiter):
                if delimiter != ';\n':
                    statement = statement.replace(';', '; --').replace(delimiter, ';') # found delimiter, add dash symbols (or any symbols you want) for converting MySQL statements with multiply delimiters in SQL statement
                c.execute(statement) # execute current statement
                statement = '' # begin collect next statement

Hope it will help!