Development Based on ODBC

Open Database Connectivity (ODBC) is a Microsoft API for accessing databases based on the X/OPEN CLI. Applications interact with the database through the APIs provided by ODBC, which enhances their portability, scalability, and maintainability.

Figure 1 shows the system structure of ODBC.

Figure 1 ODBC system structure

GaussDB supports ODBC in the following environments.

**Table 1** OSs Supported by ODBC
OS	Platform
EulerOS V2.0SP5	x86_64
EulerOS V2.0SP9	Arm64
EulerOS V2.0SP10	x86_64
EulerOS V2.0SP10	Arm64
Windows 7	x86_32
Windows 7	x86_64
Windows Server 2008	x86_32
Windows Server 2008	x86_64
Kylin V10	x86_64
Kylin V10	Arm64
UnionTech V20	x86_64
UnionTech V20	Arm64
Huawei Cloud EulerOS 2.0	x86_64
Huawei Cloud EulerOS 2.0	Arm64

The ODBC Driver Manager running on Unix or Linux can be unixODBC or iODBC. unixODBC-2.3.7 is used as the component for connecting to the database.

Windows has a native ODBC Driver Manager. You can locate Data Sources (ODBC) by choosing Control Panel > Administrative Tools.

The current database ODBC driver is based on an open-source version and may be incompatible with data types tinyint, smalldatetime, nvarchar, and nvarchar2.

ODBC Constraints

ODBC does not support read on the standby node.
ODBC does not support user-defined types and does not support user-defined parameters in stored procedures.
ODBC does not support DR switchover.
When the proc_outparam_override parameter is enabled for the database, ODBC cannot properly call the stored procedure that contains the out parameter.