Release 10.1A: OpenEdge Data Management:
DataServer for ODBC

Case sensitivity

By default, an OpenEdge database is case insensitive; however, you can set the attributes of a field to define it as either case sensitive or case insensitive. If you intend to do this, consider the following:

Schema pull criteria is case sensitive against SQL database qualifiers.
Pattern-matching literals in data-source access statements retrieve case-sensitive data.
OpenEdge considers the user ID and password submitted at connection time to be case sensitive.

If an indexed field is case insensitive, OpenEdge does not distinguish between uppercase and lowercase letters for that index when sorting or matching data. In general, this flexibility in an application makes data entry easier for end users because they can enter lowercase or uppercase versions of an index. However, if you want to enforce an uppercase/lowercase distinction in your applications, set the attribute to case sensitive.

The DataServer makes this feature compatible across OpenEdge and ODBC data sources. Case insensitivity for indexes is particularly useful when migrating OpenEdge applications to run with an ODBC data source. To support it, an extra column must be added to the data source immediately before the indexed column. In most cases, this column is named _S#_column (exceptions are noted in the following sections). See the "Adding extended 4GL support" section for instructions on adding this column automatically with the Progress-to-ODBC utility for Sybase.

Specific ODBC data sources handle case sensitivity as described in the following sections.

DB2

DB2 is case sensitive. Be sure to consider case sensitivity when you perform comparisons (equals or matches).

Informix

The DataServer assumes case sensitivity since ODBC does not allow you to determine case. This might affect how records are sorted and the order in which they are returned to the OpenEdge client. Be sure to consider case sensitivity when you perform comparisons (equals or matches).

In Informix, the column that you add to the data source to support case insensitivity for indexes is named _S__column rather than _S#_column. This is because Informix does not allow the pound sign in object names.

Sybase

For Sybase, the System Administrator sets case sensitivity at the Sybase level.