15.10 - SQLGetTypeInfo - ODBC Driver for Teradata

ODBC Driver for Teradata User Guide

prodname
ODBC Driver for Teradata
vrm_release
15.10
category
User Guide
featnum
B035-2509-035K

The ODBC function SQLGetTypeInfo function can be used to enumerate all ODBC SQL types supported by a data source or retrieve information for a single ODBC SQL type. In both cases it returns various information about the ODBC driver and Database specifics for each ODBC SQL type. More than one data type supported by the data source can map to a single ODBC SQL type identifier.

The function returns the results as a standard result set, ordered by DATA_TYPE and then by how closely the data type maps to the corresponding ODBC SQL data type.

To support the JSON data type, the Teradata specific column TDODBC_DATA_TYPE will be set to SQL_TD_JSON or SQL_TD_WJSON depending on the session character set. The JSON data type is only exposed if LOB support is enabled.

The following table shows how JSON will be exposed by SQLGetTypeInfo using a non-Unicode session. Note that the data type is the "key" passed to SQLGetTypeInfo, thus two rows are returned for SQLGetTypeInfo(SQL_LONGVARCHAR).

 

Type Name

Data Type

Column Size

Create Params

TDODBC_DATA_TYPE

CLOB

SQL_LONGVARCHAR

2097088000

Max length

SQL_LONGVARCHAR

JSON

SQL_LONGVARCHAR

16776192

Max length

SQL_TD_JSON (18004)

In a Unicode session, the table looks like:

 

Type Name

Data Type

Column Size

Create Params

TDODBC_DATA_TYPE

CLOB() CHARACTER SET UNICODE

SQL_WLONGVARCHAR

1048544000

Max length

SQL_WLONGCHAR

JSON() CHARACTER SET UNICODE

SQL_WLONGVARCHAR

8388096

Max length

SQL_TD_WJSON (18005)

Note: JSON will be returned as NULLABLE by SQLGetTypeInfo. This is the same as is returned for XML. CLOB and BLOB data types are still returned as non-NULLABLE.