# Updatable Result Sets

The functionality of updatable result sets in a server environment are similar to an embedded environment in Derby, with the exception of the following differences:

- The Network Client requires that there be at least one column in the select list from the target table. For example, the following statement will fail in a server environment:

      select 1, 2 from t1 for update of c11

  The Network Client driver looks at both of the columns in the select list and cannot determine the target table for update/delete by looking at the column metadata. This requirement is not necessary in an embedded environment.
- The embedded driver allows for statement name changes when there is an open result set on the statement object. This is not supported in a server environment.

Other differences between updatable result sets in a server or embedded environment can be found in the following table.

Table 1. Comparison of updatable result sets features in server and embedded environments
Embedded environment | Server environment
--- | ---
updateBytes on CHAR, VARCHAR, LONG VARCHAR datatypes supported. | Not supported
updateTime on TIMESTAMP datatypes supported. | Not supported
updateClob and updateBlob supported. | Not supported

Parent topic: Differences between running Derby in embedded mode and using the Network Server
Related concepts
Differences between the embedded client and the network client driver
User authentication differences
Differences in JDBC 3.0 methods
Differences using the Connection.setReadOnly method
Related reference
Error message differences