If the model’s primary key is an AutoField it does not retrieve and set the primary key attribute, as save() does, unless the database backend supports it (currently PostgreSQL). It does not work with many-to-many relationships. Changed in Django 1.9: Support for using bulk_create()...
Set Foreign Key Checks off in an insert script Setting SQL server Express maximum memory usage Shredding deadlock information from XML data shrinking a database thru the mgmt studio interface seems stuck shrinking is very very slow ... any reasons ? Shrinking SQL .MDF & LDF file size not wor...
Delete by foreign field GeoZone.get('name':'Roman Empire').objects('users').deleteUser.objects.filter('zone::name':'Roman Empire').delete# Both statements are equal:# DELETE# FROM users# WHERE id IN (# SELECT users.*# FOR users# LEFT JOIN geo_zones users_zone_0 ON users.zone_id ...
FeatureDocument Databases (e.g., MongoDB)Relational Databases (e.g., MySQL, PostgreSQL) Data Structure Stores data as documents (e.g., JSON, BSON), allowing for flexible, hierarchical structures. Stores data in tables with rows and columns, following a predefined schema. Schema Flexibility Sche...
将 CREATE TABLE 表1 AS SELECT * FROM 表2;改写为 CREATE TABLE 表1;INSERT INTO 表2 SELECT ....
Depending on which database you’re using (e.g. PostgreSQL vs. MySQL), count() may return a long integer instead of a normal Python integer. This is an underlying implementation quirk that shouldn’t pose any real-world problems. Note that if you want the number of items in a QuerySet...
Oracle and PostgreSQL use server-side cursors to stream results from the database without loading the entire result set into memory. The Oracle database driver always uses server-side cursors. With server-side cursors, the chunk_size parameter specifies the number of results to cache at the data...
Set Foreign Key Checks off in an insert script Setting SQL server Express maximum memory usage Shredding deadlock information from XML data shrinking a database thru the mgmt studio interface seems stuck shrinking is very very slow ... any reasons ? Shrinking SQL .MDF & LDF file size not wor...
On PostgreSQL only, you can pass no_key=True in order to acquire a weaker lock, that still allows creating rows that merely reference locked rows (through a foreign key, for example) while the lock is in place. The PostgreSQL documentation has more details about row-level lock modes. You...
If this is the case, it would explain your error message and you should disable this option to allow SQL Server to run in thread mode, as it is designed for most operations. If that returns 0 then run:select value_in_use from sys.configurations where name = 'Ole Automation Procedures'...