Progress
Open Client
Developer’s Guide
Metadata Methods
The metadata information about the SDOResultSet is exposed through the
com.progress.open4gl.SDOResultSetMetaData
interface. An object that implementsSDOResultSetMetaData
is returned using theSDOResultSet.getMetaData()
method. The interface,com.progress.open4gl.SDOResultSetMetaData
, is an extended subset of the standard JDBC 2java.sql.ResultSetMetaData
interface. Note that 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 Metadata Methods
The supported standard JDBC 2 methods include:
The number of columns in the SDOResultSet.
The
name
of the column.
The SQL type of the column.
0 if this column is mandatory (does not allow the 4GL unknown value (?)); 1 if it is not mandatory (allows the 4GL unknown value (?)).
The maximum display size width of this column in characters.
The 4GL dictionary label for this column.
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.
True if the column is an SDOResultSet read-only column.
False if the column is an SDOResultSet read-only column.
The 4GL data type name of the column.
Nonstandard Metadata Methods [Extension]
SDOResultSetMetaData extensions to the standard interface include the following features:
- Methods that expose metadata information that exists in the schema of the Progress database but does not have an equivalent standard (for example, the
getColumnInitialValue()
method).NOTE: The SDOResultSetMetaData interface also hides SmartDataObject system fields. SmartDataObject system fields are fields (such as- Methods that expose 4GL-to-Java mapping information (for example, the
getColumnJavaTypeName()
method).changedFieldsList
) that are used only by the SmartDataObject implementation code. They have no meaning for the Open Client and should not be accessed directly.The list of supported nonstandard SDOResultSetMetaData methods follows:
The 4GL dictionary validation expression.
The 4GL dictionary validation message.
The 4GL dictionary display format.
The 4GL dictionary initial value as a string.
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 Programming Java Clients."
The Java type name.
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