U
SW] @ s d Z ddlmZ ddlZddlZddlT ddlmZ ddlmZ ddlmZ ddlm Z dd lm
Z
dd
lm Z G d d d e Z
d
d ZG dd de ZG dd deZdZG dd dedeZG dd deZG dd deZdd ZdS ) a
Lightweight schema migrations.
NOTE: Currently tested with SQLite and Postgresql. MySQL may be missing some
features.
Example Usage
-------------
Instantiate a migrator:
# Postgres example:
my_db = PostgresqlDatabase(...)
migrator = PostgresqlMigrator(my_db)
# SQLite example:
my_db = SqliteDatabase('my_database.db')
migrator = SqliteMigrator(my_db)
Then you will use the `migrate` function to run various `Operation`s which
are generated by the migrator:
migrate(
migrator.add_column('some_table', 'column_name', CharField(default=''))
)
Migrations are not run inside a transaction, so if you wish the migration to
run in a transaction you will need to wrap the call to `migrate` in a
transaction block, e.g.:
with my_db.transaction():
migrate(...)
Supported Operations
--------------------
Add new field(s) to an existing model:
# Create your field instances. For non-null fields you must specify a
# default value.
pubdate_field = DateTimeField(null=True)
comment_field = TextField(default='')
# Run the migration, specifying the database table, field name and field.
migrate(
migrator.add_column('comment_tbl', 'pub_date', pubdate_field),
migrator.add_column('comment_tbl', 'comment', comment_field),
)
Renaming a field:
# Specify the table, original name of the column, and its new name.
migrate(
migrator.rename_column('story', 'pub_date', 'publish_date'),
migrator.rename_column('story', 'mod_date', 'modified_date'),
)
Dropping a field:
migrate(
migrator.drop_column('story', 'some_old_field'),
)
Making a field nullable or not nullable:
# Note that when making a field not null that field must not have any
# NULL values present.
migrate(
# Make `pub_date` allow NULL values.
migrator.drop_not_null('story', 'pub_date'),
# Prevent `modified_date` from containing NULL values.
migrator.add_not_null('story', 'modified_date'),
)
Renaming a table:
migrate(
migrator.rename_table('story', 'stories_tbl'),
)
Adding an index:
# Specify the table, column names, and whether the index should be
# UNIQUE or not.
migrate(
# Create an index on the `pub_date` column.
migrator.add_index('story', ('pub_date',), False),
# Create a multi-column index on the `pub_date` and `status` fields.
migrator.add_index('story', ('pub_date', 'status'), False),
# Create a unique index on the category and title fields.
migrator.add_index('story', ('category_id', 'title'), True),
)
Dropping an index:
# Specify the index name.
migrate(migrator.drop_index('story', 'story_pub_date_status'))
)
namedtupleN)*) CommaClause)EnclosedClauseEntity)
Expression)Node)OPc @ s8 e Zd ZdZdd Zdd Zdd Zdd Zd
d Zd S )
Operationz/Encapsulate a single schema altering operation.c O s || _ || _|| _|| _d S N)migratormethodargskwargs)selfr
r r r r /migrate.py__init__u s zOperation.__init__c C s | j j }||S r )r
databasecompilerZ
parse_node)r noder r r r _parse_node{ s zOperation._parse_nodec C s" | |\}}| jj|| d S r )r r
r execute_sql)r r sqlZparamsr r r execute s zOperation.executec C sP t |tr| | n6t |tr*| n"t |ttfrL|D ]}| | q<d S r )
isinstancer r r runlisttuple_handle_result)r resultitemr r r r s
zOperation._handle_resultc C s2 | j }d|d< | t| j| j| j| d S )NTgenerate)r copyr getattrr
r r )r r r r r r s
z
Operation.runN) __name__
__module__ __qualname____doc__r r r r r r r r r r s s r c s t fdd}|S )Nc s4 | dd}|r | f||S t| jf||S )Nr# F)popr r& )r r r r# fnr r inner s zoperation.<locals>.inner) functoolswraps)r, r- r r+ r operation s r0 c @ s e Zd ZdZdZdd Zedd Zedd Z edd Z
d
d Z ed d
Z edd Z
edd Zed$ddZedd Zdd Zedd Zedd Zed d Zed%d d Zed!d" Zd#S )&SchemaMigratorFc C s
|| _ d S r )r )r r r r r r s zSchemaMigrator.__init__c C s0 t |trt|S t |tr$t|S t|S d S r )r ZPostgresqlDatabasePostgresqlMigratorZ
MySQLDatabase
MySQLMigratorSqliteMigrator)clsr r r r
from_database s
z SchemaMigrator.from_databasec C sJ |j }t|r| }ttdt|tdtt|tjt| |ddS )NZUPDATEZSETT)Zflat)
defaultcallableClauseSQLr r r
ZEQZParamZdb_value)r table column_namefieldr7 r r r
apply_default s z SchemaMigrator.apply_defaultc C sj |j d }|_ | |_|_| j |}||_ tdt|td|g}t|t rb|
| | t | S )NT ALTER TABLEz
ADD COLUMN)
nullname db_columnr r Zfield_definitionr: r r ForeignKeyFieldextendget_inline_fk_sqlr9 )r r; r< r= Z
field_nullZ field_clausepartsr r r alter_add_column s
z SchemaMigrator.alter_add_columnc C s$ t dt|jjjtt|jjgS )N
REFERENCES)r: r rel_model_metadb_tabler to_fieldrB r r= r r r rE s z SchemaMigrator.get_inline_fk_sqlc C s t d S r NotImplementedError)r r; r< r= r r r add_foreign_key_constraint s z)SchemaMigrator.add_foreign_key_constraintc C s |j s |jd kr td| t|t}|r8|js8td| |||g}|j sn|| |||| ||g |r| j
r| | |||j
jj|jj |S )Nz!%s is not null but has no defaultz'Foreign keys must specify a `to_field`.)r@ r7
ValueErrorr rC rL rG rD r> add_not_nullexplicit_create_foreign_keyappendrP rI rJ rK rB )r r; r< r= is_foreign_key
operationsr r r
add_column s*
zSchemaMigrator.add_columnc C s t d S r rN r r; r< r r r drop_foreign_key_constraint s z*SchemaMigrator.drop_foreign_key_constraintTc C sr t dt|t dt|g}|r.|t d t| }dd | j|D }||krj| jrj| |||gS |S d S )Nr? z DROP COLUMNZCASCADEc S s g | ]
}|j qS r column).0Z foreign_keyr r r
<listcomp> s z.SchemaMigrator.drop_column.<locals>.<listcomp>)r: r rT r9 r get_foreign_keysexplicit_delete_foreign_keyrY )r r; r< cascadenodesZdrop_column_nodeZ
fk_columnsr r r drop_column s
zSchemaMigrator.drop_columnc C s* t tdt|tdt|tdt|S )Nr? z
RENAME COLUMNTOr9 r: r )r r; old_namenew_namer r r
rename_column s z SchemaMigrator.rename_columnc C s t dt|t dt|gS )Nr? z ALTER COLUMN)r: r r r; r[ r r r
_alter_column s
z SchemaMigrator._alter_columnc C s" | ||}|td t| S )Nz SET NOT NULLri rT r: r9 r r; r[ ra r r r rR " s zSchemaMigrator.add_not_nullc C s" | ||}|td t| S )Nz
DROP NOT NULLrj rk r r r
drop_not_null( s z SchemaMigrator.drop_not_nullc C s t tdt|tdt|S )Nr? z RENAME TOrd r re rf r r r rename_table. s zSchemaMigrator.rename_tablec C sL | j }|rdnd}tt|t|||tdt|tdd |D S )NzCREATE UNIQUE INDEXz CREATE INDEXONc S s g | ] }t |qS r r r\ r[ r r r r] ? s z,SchemaMigrator.add_index.<locals>.<listcomp>)r r r9 r: r
index_namer )r r; columnsuniquer Z statementr r r add_index6 s
zSchemaMigrator.add_indexc C s t tdt|S )N
DROP INDEXrd r r; rq r r r
drop_indexA s zSchemaMigrator.drop_indexN)T)F)r& r' r( rS r_ r classmethodr6 r0 r> rG rE rP rW rY rb rg ri rR rl rn rt rw r r r r r1 s>
!
r1 c s( e Zd Zdd Ze fddZ ZS )r2 c C s& d}| j || }dd | D S )Nai
SELECT pg_attribute.attname
FROM pg_index, pg_class, pg_attribute
WHERE
pg_class.oid = '%s'::regclass AND
indrelid = pg_class.oid AND
pg_attribute.attrelid = pg_class.oid AND
pg_attribute.attnum = any(pg_index.indkey) AND
indisprimary;
c S s g | ] }|d qS r r )r\ rowr r r r] U s z;PostgresqlMigrator._primary_key_columns.<locals>.<listcomp>)r r fetchall)r Ztblquerycursorr r r _primary_key_columnsI s
z'PostgresqlMigrator._primary_key_columnsc
s | |}tt| }|j||ddg}t|dkrd||d f }d}| j||f}t| rd||d f } | |j|| dd |S )NT)r# z %s_%s_seqr z
SELECT 1
FROM information_schema.sequences
WHERE LOWER(sequence_name) = LOWER(%s)
)
r~ superr2 rn lenr r boolfetchonerT )
r re rf Zpk_namesZ ParentClassrV Zseq_namer| r} Z new_seq_name __class__r r rn W s
z PostgresqlMigrator.rename_table)r& r' r( r~ r0 rn
__classcell__r r r r r2 H s r2 )rA
definitionr@ pkr7 extrac @ s: e Zd Zedd Zedd Zedd Zd
dd ZdS ) MySQLColumnc C s
| j dkS )NZPRIr r r r r is_pkr s zMySQLColumn.is_pkc C s
| j dkS )NZUNIr r r r r is_uniquev s zMySQLColumn.is_uniquec C s
| j dkS )NZYES)r@ r r r r is_nullz s zMySQLColumn.is_nullNc C s |d kr| j }|d kr | j}t|t| jg}| jrB|td |rV|td n|td | jrx|td | jr|t| j t | S )NZUNIQUEZNULLNOT NULLz PRIMARY KEY)
r rA r r: r r rT r r r9 )r r< r rF r r r r ~ s" zMySQLColumn.sql)NN)r& r' r( propertyr r r r r r r r r q s
r Z_Columnc @ s e Zd ZdZdZedd Zdd Zedd Zdd Z ed
d Z
d d
Z edd Z edd Z
edd Zedd ZdS )r3 Tc C s t tdt|tdt|S )Nz RENAME TABLErc rd rm r r r rn s zMySQLMigrator.rename_tablec C s@ | j d| }| }|D ] }t| }|j|kr | S q dS )Nz DESCRIBE %s;F)r r r{ r rA )r r; r< r} Zrowsrz r[ r r r _get_column_definition s
z$MySQLMigrator._get_column_definitionc C sR d|||f }t tdt|tdt|tdtt|tdt|tt| S )Nzfk_%s_%s_refs_%sr? zADD CONSTRAINTz FOREIGN KEYrH )r9 r: r r )r r; r< ZrelZ
rel_columnZ
constraintr r r rP s
z(MySQLMigrator.add_foreign_key_constraintc C s6 | j d||f}| }|s.td||f |d S )NzSELECT constraint_name FROM information_schema.key_column_usage WHERE table_schema = DATABASE() AND table_name = %s AND column_name = %s;z=Unable to find foreign key constraint for "%s" on table "%s".r )r r r AttributeError)r r; r< r} r! r r r get_foreign_key_constraint s z(MySQLMigrator.get_foreign_key_constraintc C s& t tdt|tdt| ||S )Nr? zDROP FOREIGN KEY)r9 r: r r rX r r r rY s z)MySQLMigrator.drop_foreign_key_constraintc C s g S r r rM r r r rE s z MySQLMigrator.get_inline_fk_sqlc C s. | ||}ttdt|td|jddS )Nr? MODIFYFr )r r9 r: r r rh r r r rR s
zMySQLMigrator.add_not_nullc C s< | ||}|jrtdttdt|td|jddS )Nz Primary keys can not be nullr? r Tr )r r rQ r9 r: r r rh r r r rl s
zMySQLMigrator.drop_not_nullc C s t dd | j|D }||k}| ||}ttdt|tdt||j|d}|r|| }| |||| |||j
|j gS |S d S )Nc s s | ]}|j |fV qd S r rZ )r\ Zfkr r r <genexpr> s z.MySQLMigrator.rename_column.<locals>.<genexpr>r? ZCHANGE)r< ) dictr r^ r r9 r: r r rY rP Z
dest_tableZ dest_column) r r; re rf Z
fk_objectsrU r[ Z
rename_clauseZ fk_metadatar r r rg s0
zMySQLMigrator.rename_columnc C s t tdt|tdt|S )Nru ro rd rv r r r rw s zMySQLMigrator.drop_indexN)r& r' r( rS r_ r0 rn r rP r rY rE rR rl rg rw r r r r r3 s&
r3 c @ s e Zd ZdZedZedZedZedej Z
dd Z dd Z e
d
d Zd d
Ze
dddZe
dd Ze
dd Ze
dd ZdS )r4 z
SQLite supports a subset of ALTER TABLE queries, view the docs for the
full details http://sqlite.org/lang_altertable.html
z
(.+?)\((.+)\)z(?:[^,(]|\([^)]*\))+z
["`']?([\w]+)z FOREIGN KEY\s+\("?([\w]+)"?\)\s+c C s | j d| }dd |jD S )Nzselect * from "%s" limit 1c S s g | ] }|d qS ry r )r\ r" r r r r] s z4SqliteMigrator._get_column_names.<locals>.<listcomp>)r r descriptionr r; resr r r _get_column_names s z SqliteMigrator._get_column_namesc C s | j dd| g}| S )NzBselect name, sql from sqlite_master where type=? and LOWER(name)=?r; )r r lowerr r r r r _get_create_table s
z SqliteMigrator._get_create_tablec s t dd j|D }| |kr6td||f |\}}j|}j| t dd|}j
| \}}j
|} dd | D }
g } g } g }
|
D ]}j| \}||kr
|||}|r6| | |
| j| \}| | q| | | ds| | |
| qtt|
| }|| d d
} shd d
}n |kr fd d
}g }| D ]F}j|}|d k r| d
|kr||}|r|| q|d }td| tj}| d| |}d|}ttdt |td| |f g}ttdt |t dd | D tdt dd |
D tdt |}|| |ttdt | | || t!dd
|D ]R}||j"kr|t|j# n. r$|j#| }|d k r|t| q|S )Nc s s | ]}|j V qd S r )rA r rp r r r r s z0SqliteMigrator._update_column.<locals>.<genexpr>z"Column "%s" does not exist on "%s"z\s+ c S s g | ] }| qS r stripr\ colr r r r] 8 s z1SqliteMigrator._update_column.<locals>.<listcomp>)ZforeignZprimaryc S s | S r r
column_defr r r <lambda>S z/SqliteMigrator._update_column.<locals>.<lambda>c S s d S r r r r r r r V r c s j d | S )NzFOREIGN KEY ("%s") )fk_resubr
new_columnr r r r Y s r Z__tmp__z
("?)%s("?)z\1%s\2, zDROP TABLE IF EXISTSz%s (%s)z INSERT INTOc S s g | ] }t |qS r r r r r r r] v s ZSELECTc S s g | ] }t |qS r r r r r r r] x s ZFROMz
DROP TABLEc S s | j S r )r )idxr r r r r )%setr Z get_columnsr rQ r Z get_indexesr^ rer column_researchgroupscolumn_split_refindallcolumn_name_rematchrT
startswithr zipgetr compileIjoinr9 r: r r r r rn filterrr r
_fix_index) r r; column_to_updater, rr Z create_tableZindexesZ
raw_createZ raw_columnsZ
split_columnsZ column_defsZnew_column_defsZnew_column_namesZoriginal_column_namesr r< Znew_column_defZoriginal_to_newZ fk_filter_fnZcleaned_columnsr Z
temp_tableZrgxZcreateZqueriesZpopulate_tableindexr r r r _update_column s
z SqliteMigrator._update_columnc
C s | |}t|dkr"|||S |dd\}}t| |dkrXd||||f S |ddd d}dd |D }g }|D ]2} td
| | rt| t|d } || qd |d d
d |D f S )N (r z%s(%s)r ,c S s g | ]}| d qS )z"`[]' r )r\ partr r r r] s z-SqliteMigrator._fix_index.<locals>.<listcomp>z%s(?:['"`\]]?\s|$)z%s(%s)r c s s | ]}d | V qdS )z"%s"Nr )r\ cr r r r s z,SqliteMigrator._fix_index.<locals>.<genexpr>) splitr replacersplitr r Z new_columnerT r )
r r r r rF ZlhsZrhsrr Zcleanr[ r r r r s
zSqliteMigrator._fix_indexTc C s | ||dd S )Nc S s d S r r )abr r r r r z,SqliteMigrator.drop_column.<locals>.<lambda>r )r r; r< r` r r r rb s zSqliteMigrator.drop_columnc s fdd}| |||S )Nc s | | S r r r< r rf r r _rename s z-SqliteMigrator.rename_column.<locals>._renamer )r r; re rf r r r r rg s z SqliteMigrator.rename_columnc C s dd }| |||S )Nc S s |d S )Nz NOT NULLr r r r r
_add_not_null s z2SqliteMigrator.add_not_null.<locals>._add_not_nullr )r r; r[ r r r r rR s zSqliteMigrator.add_not_nullc C s dd }| |||S )Nc S s | ddS )Nr r r r r r _drop_not_null s z4SqliteMigrator.drop_not_null.<locals>._drop_not_nullr )r r; r[ r r r r rl s z SqliteMigrator.drop_not_nullN)T)r& r' r( r) r r r r r r r r r r0 r r rb rg rR rl r r r r r4 s$
p
r4 c O s | D ] }| qd S r )r )rV r r0 r r r migrate s r )r) collectionsr r. r Zpeeweer r r r r r
objectr r0 r1 r2 Z_column_attributesr r3 r4 r r r r r <module> s* e -'"v =