Data Transformation Engine ODBC Adapter Reference Guide

ODBC Adapter Reference Guide
7
Chapter 2 - Database Columns and
Types
The Database Interface Designer and mtsmaker with the Type Tree Maker
generate type trees for queries, tables, views, and stored procedures in an ODBC-
compliant RDBMS (Relational Database Management System). Item types are
created in a type tree that represents the data types of the columns of a query,
table, view, or stored procedure.
The Database Interface Designer and mtsmaker get information about columns
by calling the ODBC Driver Manager that calls the ODBC driver for your RDBMS to
describe the columns associated with a query, table, view, or stored procedure.
The ODBC driver for the RDBMS has mapped the data types in each column to
ODBC data types as appropriate. From the RDBMS, the ODBC Driver Manager
returns the ODBC data type, length, and other information to the Database
Interface Designer and mtsmaker. The ODBC data types are then mapped to
types in a type tree. The Database Interface Designer and mtsmaker have no
knowledge of the RDBMS-specific data types—only the ODBC data types.
Item Type Properties
The following table lists the ODBC data types and the values of the item type
properties to which they correspond when the type tree is generated.
ODBC Data Type Interpret as
Item Subclass,
Presentation Length
SQL_VARCHAR Character Text *
SQL_CHAR Character Text *
SQL_DECIMAL Character Number, Decimal *
SQL_NUMERIC Character Number, Decimal *
SQL_SMALLINT Character Number, Integer 6
SQL_INTEGER Character Number, Integer 11
SQL_REAL Binary Number, Float 4
SQL_FLOAT Binary Number, Float 8