A.release the lock, Read the data, set the lock, change the data

B.Set the lock, read the data, release the lock, change the data

C.Set the lock, read the data, change the data, release the lock

D.Read the data, set the lock, change the data, release the lock

A.When accessing by index

B.When accessing using the left-justified part of the key

C.When accessing always by primary key

D.When accessing by secondary key

E.When accessing mainly single records

A.PUBLIC SECTION, PROTECTED SECTION, PRIVATE SECTION

B.PRIVATE SECTION, PROTECTED SECTION, PUBLIC SECTION

C.The order is handled automatically.

D.The order doesn't matter

A.Final

B.Abstract

C.Protected

D.Private

A.It can contain an importing parameter.

B.It must be a singleton.

C.It must contain a returning parameter.

D.It can be used in logical expressions.

E.It can contain a changing parameter.

F.It can be used in SELECT statements.

G.It can contain an exporting parameter.