OracleCommandBuilder Class
An OracleCommandBuilder
object provides automatic SQL generation for the OracleDataAdapter
when updates are made to the database.
Class Inheritance
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Data.Common.DbCommandBuilder
OracleDataAccess.Client.OracleCommandBuilder
Declaration
// C# public sealed class OracleCommandBuilder : DbCommandBuilder
Requirements
Provider | ODP.NET, Unmanaged Driver | ODP.NET, Managed Driver | ODP.NET Core |
---|---|---|---|
Assembly |
|
|
|
Namespace |
|
|
|
.NET Framework |
- |
||
.NET (Core) |
- |
- |
Thread Safety
All public static methods are thread-safe, although instance methods do not guarantee thread safety.
Remarks
OracleCommandBuilder
automatically generates SQL statements for single-table updates when the SelectCommand
property of the OracleDataAdapter
is set. An exception is thrown if the DataSet
contains multiple tables. The OracleCommandBuilder
registers itself as a listener for RowUpdating
events whenever its DataAdapter
property is set. Only one OracleDataAdapter
object and one OracleCommandBuilder
object can be associated with each other at one time.
To generate INSERT
, UPDATE
, or DELETE
statements, the OracleCommandBuilder
uses ExtendedProperties
within the DataSet
to retrieve a required set of metadata. If the SelectCommand
is changed after the metadata is retrieved (for example, after the first update), the RefreshSchema
method should be called to update the metadata.
OracleCommandBuilder
first looks for the metadata from the ExtendedProperties
of the DataSet
; if the metadata is not available, OracleCommandBuilder
uses the SelectCommand
property of the OracleDataAdapter
to retrieve the metadata.
Example
The following example performs an update on the EMP
table. It uses the OracleCommandBuilder
object to create the UpdateCommand
for the OracleDataAdapter
object when OracleDataAdapter.Update()
is called.
// C# using System; using System.Data; using Oracle.DataAccess.Client; class OracleCommandBuilderSample { static void Main() { string constr = "User Id=scott;Password=tiger;Data Source=oracle"; string cmdstr = "SELECT empno, sal from emp"; // Create the adapter with the selectCommand txt and the // connection string OracleDataAdapter adapter = new OracleDataAdapter(cmdstr, constr); // Create the builder for the adapter to automatically generate // the Command when needed OracleCommandBuilder builder = new OracleCommandBuilder(adapter); // Create and fill the DataSet using the EMP DataSet dataset = new DataSet(); adapter.Fill(dataset, "EMP"); // Get the EMP table from the dataset DataTable table = dataset.Tables["EMP"]; // Indicate DataColumn EMPNO is unique // This is required by the OracleCommandBuilder to update the EMP table table.Columns["EMPNO"].Unique = true; // Get the first row from the EMP table DataRow row = table.Rows[0]; // Update the salary double sal = double.Parse(row["SAL"].ToString()); row["SAL"] = sal + .01; // Now update the EMP using the adapter // The OracleCommandBuilder will create the UpdateCommand for the // adapter to update the EMP table adapter.Update(dataset, "EMP"); Console.WriteLine("Row updated successfully"); } }