Application development with C/C++ - DB2 Express-C: The Developer for XML, PHP, C/C++, Java, and .NET - page 185

4.5.4 Connecting and disconnect to and from a database

Table 4-8 lists some APIs that can be used in working with a connection to a
database.

Table 4-8 Connection-related CLI APIs

CLI API Purpose

SQLConnect Connect to a database given a database name, user ID, and

password.

SQLDriverConnect Connect to a database (has expanded connection

parameters).

SQLBrowseConnect Use iterative method to connect to a database.

SQLSetConnectAttr Set connection attributes.

SQLSetConnection Sets the current active connection. Used for embedded

SQL modules within a CLI application.

SQLGetConnectAttr Get connection option value.

SQLDisconnect Disconnect from the database.

There are various APIs to choose from for connecting to a database. The
SQLDriverConnect() API expands the functionality of SQLConnect() by allowing
extra connection parameters and the ability to get connection information from
the user. The SQLBrowseConnect() is an iterative way of connecting to the
database. In our application, we use the SQLConnect( ) API:
SQLRETURN SQLConnect (
SQLHDBC ConnectionHandle, /* hdbc */
SQLCHAR *ServerName, /* szDSN */
SQLSMALLINT ServerNameLength, /* cbDSN */
SQLCHAR *UserName, /* szUID */
SQLSMALLINT UserNameLength, /* cbUID */
SQLCHAR *Authentication, /* szAuthStr */
SQLSMALLINT AuthenticationLength); /* cbAuthStr */

In our code, we add the following line (Example 4-33 on page 186) to establish a
default database connection and later to disconnect from the database.