It is a standalone tool and PHP library that can be used to apply migration scripts to a database.
- Supports any database accessible via PHP's PDO extension.
- Uses plain SQL for migrations
- It does not provide any mechanism for make that SQL portable across different database systems
- Individual migrations are run inside a transaction (by default)
- Can create and drop databases
- Can generate a file of SQL to generate the current schema
- Makes setting up new databases a one-step process instead of running all migrations
- Diff of full schema provides an additional check for code review
TBD
You can run ./vendor/bin/langur --help to see the full list of commands
options.
The following example demonstrates:
- Creating a migration that creates a new
userstable with a few columns including anamecolumn - Creating the database and applying that migration
- Creating another migration to add new
first_nameandlast_namecolumns to theuserstable, initializing the data from thenamecolumn and dropping thenamecolumn - Running that migration
- Rolling back that migration
- Dumping the schema
$ export LANGUR_DSN="sqlite3:example.sqlite"
$ ./vendor/bin/langur new create_users <<SQL
-- langur:up
create table users (
id integer,
name varchar(255),
email varchar(255) not null
);
insert into users (id, name, email) values
(1, 'Jim Winstead', 'jim@example.com'),
(2, 'Rihanna', 'madonna@example.com');
-- langur:down
SQL
$ ./vendor/bin/langur up
$ ./vendor/bin/langur new split_name_in_users <<SQL
-- langur:up
alter table users add first_name varchar(255);
alter table users add last_name varchar(255);
-- we assume a space with no name is just a first name
update users set
first_name = case when name like '% %' then substr(name, 1, instr(name, ' ') - 1) else name end,
last_name = case when name like '% %' then substr(name, instr(name, ' ') + 1) else '' end;
alter table users drop name;
-- langur:down
alter table users add name varchar(255) after id;
update users set name = first_name || case when last_name <> '' then ' ' || last_name else '' end;
alter table users drop first_name, last_name;
SQL
$ ./vendor/bin/langur migrate
$ sqlite3 example.sqlite3 "select * from users"
$ ./vendor/bin/langur rollback
$ sqlite3 example.sqlite3 "select * from users"
$ ./vendor/bin/langur dumpOld World monkeys of the genus Semnipithecus are more commonly known as langurs, and are native to the Indian subcontinent.
Jim Winstead, September 2024