View the current number of connections of the SQL Server database

1. Number of connections to the query database

Use masterselect * From DBO. sysprocesses where dbid in (select dbid from sysdatabases where name = 'dbname ')

Dbname indicates the name of the database to be queried, and the number of records is the number of connections of the database.

2. query the number of user connections

Exec sp_who 'username'

The number of records is the number of connections of the user.

Foreign key constraint cascade update and Deletion

Alter table xxx add constraint fk_xxx foreign key (xxid) References XXX (xxid) on update cascade on Delete Cascade