What is ODBC?
The ODBC API
Open Database Connectivity (ODBC) is a standard application
programming interface (API) developed by Microsoft. It allows a single
application to access a variety of data sources for which ODBC-compliant
drivers exist. The application uses Structured Query Language (SQL) as
the standard data access language.
The ODBC API defines the following:
-
A library of ODBC function calls that connect to the data
source, execute SQL statements, and retrieve results -
A standard way to connect and log in to a DBMS
-
SQL syntax based on the X/Open and SQL Access Group (SAG) CAE
specification (1992) -
A standard representation for datatypes
-
A standard set of error codes
Accessing ODBC data
sources
Applications that provide an ODBC interface, like PowerBuilder,
can access data sources for which an ODBC driver exists. An ODBC data
source driver is a dynamic link library (DLL) that implements ODBC
function calls. The application invokes the ODBC driver to access a
particular data source.
Accessing Unicode data
Using the ODBC interface, PowerBuilder can connect, save, and
retrieve data in both ANSI/DBCS and Unicode databases but does not
convert data between Unicode and ANSI/DBCS. When character data or
command text is sent to the database, PowerBuilder sends a Unicode
string. The driver must guarantee that the data is saved as Unicode data
correctly. When PowerBuilder retrieves character data, it assumes the
data is Unicode.
A Unicode database is a database whose character set is set to a
Unicode format, such as UTF-8, UTF-16, UCS-2, or UCS-4. All data must be
in Unicode format, and any data saved to the database must be converted
to Unicode data implicitly or explicitly.
A database that uses ANSI (or DBCS) as its character set might use
special datatypes to store Unicode data. Columns with these datatypes
can store only Unicode data. Any data saved into such a column must be
converted to Unicode explicitly. This conversion must be handled by the
database server or client.