Sybase considerations

Allowing null values

By default, Sybase does not allow null values in string columns (like VARCHAR, TEXT, and so on). You can change this default value for a database using "isql" by issuing the following command:

sp_dboption databasename, "allow nulls by default", true

In this example "databasename" is your database name.

Large character data

The large character data fields are stored in a column of type TEXT. Sybase allows TEXT fields to be queried only using the SQL "LIKE" operator. Queries against the columns that perform the SQL "IS NULL" or "IS NOT NULL" operations are not allowed by Sybase. The alternative is to specify a column type of VARCHAR. However, the maximum allowed size for a VARCHAR in Sybase is 255 characters. This is not considered a large enough value for storing firingParameters, initParameters, descriptions, and so on.

If performing "IS NULL" and "IS NOT NULL" type queries is important and the 255 character limitation is acceptable, change these column types to VARCHAR. To accomplish this, alter the schema mapping for the Rule bean and then deploy the BRBeans JAR file.

The query APIs (in the com.ibm.websphere.brb.query package) allow for "IS NULL" and "IS NOT NULL" type queries to be performed on several of these fields. In addition, the Rule Management Application allows the firing parameters to be queried in this manner. These queries fail on Sybase with the default column type of TEXT.


Related concepts
Database considerations for BRBeans
Rule Management Application



Searchable topic ID:   cbrb_sybase
Last updated: Jun 21, 2007 8:07:48 PM CDT    WebSphere Business Integration Server Foundation, Version 5.0.2
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