3
(h                 @   s,   d dl mZ d dlmZ G dd deZdS )    )BaseDatabaseSchemaEditor)NOT_PROVIDEDc                   s   e Zd ZdZdZdZdZdZdZdZ	dZ
d	Zd
Zdd Zdd Z fddZ fddZ fddZdd Z fddZ fddZ  ZS )DatabaseSchemaEditorz+RENAME TABLE %(old_table)s TO %(new_table)szMODIFY %(column)s %(type)s NULLz#MODIFY %(column)s %(type)s NOT NULLzMODIFY %(column)s %(type)szCALTER TABLE %(table)s CHANGE %(old_column)s %(new_column)s %(type)sz)ALTER TABLE %(table)s DROP INDEX %(name)sz/ALTER TABLE %(table)s DROP FOREIGN KEY %(name)sz DROP INDEX %(name)s ON %(table)szGALTER TABLE %(table)s ADD CONSTRAINT %(name)s PRIMARY KEY (%(columns)s)z&ALTER TABLE %(table)s DROP PRIMARY KEYc             C   s   dd l }|j||jjS )Nr   )ZMySQLdb.convertersescape
convertersZconversions)selfvalueZMySQLdb r	   C/tmp/pip-install-q3hcpn_q/Django/django/db/backends/mysql/schema.pyquote_value   s    z DatabaseSchemaEditor.quote_valuec          	   C   s    |j | j}|dk	o|j d
kS )z
        MySQL doesn't accept default values for TEXT and BLOB types, and
        implicitly treats these columns as nullable.
        Ntinyblobblob
mediumbloblongblobtinytexttext
mediumtextlongtext>   r   r   r   r   r   r   r   r   )db_type
connectionlower)r   fieldr   r	   r	   r
   skip_default   s
     z!DatabaseSchemaEditor.skip_defaultc                sb   t t| j|| | j|r^|jd tfkr^| j|}| jd| j|j	j
| j|jd |g d S )Nz%UPDATE %(table)s SET %(column)s = %%s)tablecolumn)superr   	add_fieldr   defaultr   effective_defaultexecuteZ
quote_name_metadb_tabler   )r   modelr   r   )	__class__r	   r
   r   *   s    
zDatabaseSchemaEditor.add_fieldc                sR   t t| j||}| jjj| jj |jj}|dkrN|rN|j	 dkrN|j
rNdS |S )NZInnoDB
ForeignKeyF)r   r   _field_should_be_indexedr   ZintrospectionZget_storage_enginecursorr    r!   get_internal_typeZdb_constraint)r   r"   r   Zcreate_indexZstorage)r#   r	   r
   r%   6   s    z-DatabaseSchemaEditor._field_should_be_indexedc                sd   |j j|d }|j dkrL| j||jgdd}|sL| j| j||gdd tt| j	||f| S )a  
        MySQL can remove an implicit FK index on a field when that field is
        covered by another index like a unique_together. "covered" here means
        that the more complex index starts like the simpler one.
        http://bugs.mysql.com/bug.php?id=37910 / Django ticket #24757
        We check here before removing the [unique|index]_together if we have to
        recreate a FK index.
        r   r$   T)index )suffix)
r    	get_fieldr'   Z_constraint_namesr   r   Z_create_index_sqlr   r   _delete_composed_index)r   r"   fieldsargsZfirst_fieldZconstraint_names)r#   r	   r
   r,   E   s    	z+DatabaseSchemaEditor._delete_composed_indexc             C   s   |j r|d7 }n|d7 }|S )zt
        Keep the null property of the old field. If it has changed, it will be
        handled separately.
        z NULLz	 NOT NULL)null)r   r   new_typer	   r	   r
   _set_field_new_type_null_statusU   s    
z4DatabaseSchemaEditor._set_field_new_type_null_statusc                s"   | j ||}tt| j||||S )N)r1   r   r   _alter_column_type_sql)r   r   	old_field	new_fieldr0   )r#   r	   r
   r2   `   s    z+DatabaseSchemaEditor._alter_column_type_sqlc                s"   | j ||}tt| j||||S )N)r1   r   r   _rename_field_sql)r   r   r3   r4   r0   )r#   r	   r
   r5   d   s    z&DatabaseSchemaEditor._rename_field_sql)__name__
__module____qualname__Zsql_rename_tableZsql_alter_column_nullZsql_alter_column_not_nullZsql_alter_column_typeZsql_rename_columnZsql_delete_uniqueZsql_delete_fkZsql_delete_indexZsql_create_pkZsql_delete_pkr   r   r   r%   r,   r1   r2   r5   __classcell__r	   r	   )r#   r
   r      s$   r   N)Zdjango.db.backends.base.schemar   Zdjango.db.modelsr   r   r	   r	   r	   r
   <module>   s   