Establishing the language and character set for a connection

When a client application attempts to connect to a server, it sends a connection request specifying the following:

Whether or not character set conversion should be disabled for the connection (through the CS_NOCHARSETCNV property for Client-Library or the DBSETLCHARSET routine for DB-Library)
The character set to use for the connection
The language to use for the connection

Before accepting the connection, the server checks to see if it can support the requested language and character set.

Table 4-1 summarizes Adaptive Server and Open Server behavior at connection time:

**Table 4-1: Client and server conversion behavior**
Server supports client’s character set	Server supports client’s language	Server action	ct_connect	dbopen
Yes	Yes	Accepts the connection in the clients language and character set.	Returns CS_SUCCEED	Returns SUCCEED
No	Yes	If character set conversion is disabled, it accepts the connection but forces it to its own character set.	Returns CS_SUCCEED	Returns SUCCEED
No	Yes	If character set conversion is not disabled, it rejects the connection.	Returns CS_FAIL	Returns FAIL
Yes	No	Informs the client that the connection will use: us_english language The client’s character set	Returns CS_SUCCEED	Returns SUCCEED
No	No	If character set conversion is disabled, it accepts the connection but forces it to: us_english language Its own character set	Returns CS_SUCCEED	Returns SUCCEED
No	No	If character set conversion is not disabled, it rejects the connection.	Returns CS_FAIL	Returns FAIL

Once a connection is established, the server:

Generates all messages in the connection’s negotiated language and character set
Performs all necessary character set conversion for both incoming and outgoing data (provided that character set conversion is not disabled for the connection)