Locks in SQLAlchemy

[suji]

Hi,

I am using SQLAlchemy to do transactions into PosgreSQL db using Python application.
I don't know how to use locks in SQLAlchemy.

Anybody can help me to use locks in SQLAlchemy.

I am facing a problem as follows,

While running two instances of a an application parallel, it tries to insert rows into a same table. Sometimes I am getting error of duplicate primary key. Can I resolve this using lock concept?


Best Regards,
Suji

 

[vthalanki]

1) If you are using postgres database you want to run the both instance with out the error of primary key use serial data type for the table.
2) External locking procedure :

conn = engine.connect()
conn.execute("LOCK TABLES Pointer WRITE")
#do stuff with conn
conn.execute("UNLOCK TABLES")