Release 10.1A: OpenEdge Development:
Java Open Clients

Meta data methods

Meta data about the SDOResultSet is exposed through the com.progress.open4gl.SDOResultSetMetaData interface. An object that implements SDOResultSetMetaData is returned using the SDOResultSet.getMetaData() method. The interface, com.progress.open4gl.SDOResultSetMetaData, is an extended subset of the standard JDBC 2 java.sql.ResultSetMetaData interface.

SDOResultSetMetaData works with both JDK 1.1.x and JDK 1.2; therefore, much of the Java 1.2 functionality (standard JDBC ResultSetMetaData interface) is supported even with JDK 1.1.x.

JDBC 2 meta data methods

The supported standard JDBC 2 methods include the ones listed in Table 9–6.

Table 9–6: Standard JDBC meta data methods

Method	Description
int getColumnCount()	The number of columns in the SDOResultSet.
int getColumnDisplaySize (int columnIndex)	The maximum display size width of this column in characters.
String getColumnLabel (int columnIndex)	The 4GL dictionary label for this column.
String getColumnName (int columnIndex)	The name of the column.
int getColumnType (int columnIndex)	The SQL type of the column.
String getColumnTypeName (int columnIndex)	The 4GL data type name of the column.
String getTableName (int columnIndex)	The table name for this column. This is especially useful where you want to determine the original table for a column participating in a table join.
int isNullable (int columnIndex)	0 if this column is mandatory (does not allow the Unknown value (?)); 1 if it is not mandatory (allows the Unknown value (?)).
boolean isReadOnly (int columnIndex)	True if the column is an SDOResultSet read-only column.
boolean isWritable (int columnIndex)	False if the column is an SDOResultSet read-only column.

Nonstandard meta data methods [extension]

SDOResultSetMetaData extensions to the standard interface include the following features:

Methods that expose meta data information that exists in the schema of the OpenEdge database but does not have an equivalent standard (for example, getColumnInitialValue()).
Methods that expose 4GL-to-Java mapping information (for example, getColumnJavaTypeName()).
Note: The SDOResultSetMetaData interface also hides SmartDataObject system fields. SmartDataObject system fields are fields (such as changedFieldsList) that are used only by the SmartDataObject implementation code. They have no meaning for the Open Client and should not be accessed directly.

Table 9–7 lists the supported nonstandard SDOResultSetMetaData methods.

Table 9–7: Nonstandard SDOResultSetMetaData methods 

Method	Description
String getColumnFormat (int column) [Extension]	The 4GL dictionary display format.
String getColumnInitalValue (int column) [Extension]	The 4GL dictionary initial value as a string.
String getColumnJavaTypeName (int column) [Extension]	The Java type name.
int getColumnProType (int column) [Extension]	The 4GL data type number. The return value corresponds to one of the class constants defined in com.progress.open4gl.Parameter. For more information, see Chapter 4, " Passing Parameters."
String getColumnValExp (int column) [Extension]	The 4GL dictionary validation expression.
String getColumnValMsg (int column) [Extension]	The 4GL dictionary validation message.