OdbcParameter Class

Definition

Namespace:

System.Data.Odbc

Assembly:

System.Data.Odbc.dll

Package:

System.Data.Odbc v9.0.0

Source:

OdbcParameter.cs

Represents a parameter to an OdbcCommand and optionally, its mapping to a DataColumn. This class cannot be inherited.

public ref class OdbcParameter sealed : System::Data::Common::DbParameter, ICloneable

public sealed class OdbcParameter : System.Data.Common.DbParameter, ICloneable

type OdbcParameter = class
    inherit DbParameter
    interface IDataParameter
    interface IDbDataParameter
    interface ICloneable

Public NotInheritable Class OdbcParameter
Inherits DbParameter
Implements ICloneable

Inheritance

Object

DbParameter

OdbcParameter

Implements

IDataParameter IDbDataParameter ICloneable

Examples

The following example creates multiple instances of OdbcParameter through the OdbcParameterCollection within the OdbcDataAdapter. These parameters are used to select data from the data source and place the data in the DataSet. This example assumes that a DataSet and an OdbcDataAdapter have already been created by using the appropriate schema, commands, and connection.

public DataSet GetDataSetFromAdapter(
    DataSet dataSet, string connectionString, string queryString)
{
    using (OdbcConnection connection =
        new OdbcConnection(connectionString))
    {
        OdbcDataAdapter adapter =
            new OdbcDataAdapter(queryString, connection);

        // Set the parameters.
        adapter.SelectCommand.Parameters.Add(
            "@CategoryName", OdbcType.VarChar, 80).Value = "toasters";
        adapter.SelectCommand.Parameters.Add(
            "@SerialNum", OdbcType.Int).Value = 239;

        // Open the connection and fill the DataSet.
        try
        {
            connection.Open();
            adapter.Fill(dataSet);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        // The connection is automatically closed when the
        // code exits the using block.
    }
    return dataSet;
}

Public Function GetDataSetFromAdapter( _
    ByVal dataSet As DataSet, ByVal connectionString As String, _
    ByVal queryString As String) As DataSet

    Using connection As New OdbcConnection(connectionString)
        Dim adapter As New OdbcDataAdapter(queryString, connection)

        ' Set the parameters.
        adapter.SelectCommand.Parameters.Add( _
            "@CategoryName", OdbcType.VarChar, 80).Value = "toasters"
        adapter.SelectCommand.Parameters.Add( _
         "@SerialNum", OdbcType.Int).Value = 239

        ' Open the connection and fill the DataSet.
        Try
            connection.Open()
            adapter.Fill(dataSet)
        Catch ex As Exception
            Console.WriteLine(ex.Message)
        End Try
        ' The connection is automatically closed when the
        ' code exits the Using block.
    End Using

    Return dataSet
End Function

Remarks

Parameter names are not case sensitive.

When querying an Oracle database using the Microsoft OLE DB Provider for Oracle (MSDAORA) and the ODBC .NET Framework Data Provider, using the LIKE clause to query values in fixed-length fields might not return all expected matches. The reason is that when Oracle matches values for fixed-length fields in a LIKE clause, it matches the entire length of the string, including any padding trailing spaces. For example, if a table in an Oracle database contains a field named "Field1" that is defined as char(3), and you enter the value "a" into a row of that table, the following code will not return the row.

Dim queryString As String = "SELECT * FROM Table1 WHERE Field1 LIKE ?"  
Dim command As OleDbCommand = New OleDbCommand(queryString, connection)  
command.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a"  
Dim reader As OleDbDataReader = command.ExecuteReader()  

string queryString = "SELECT * FROM Table1 WHERE Field1 LIKE ?";  
OleDbCommand command = new OleDbCommand(queryString, connection);  
command.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a";  
OleDbDataReader reader = command.ExecuteReader();  

This is because Oracle stores the column value as "a " (padding "a", with trailing spaces, to the fixed field length of 3), which Oracle does not treat as a match for the parameter value of "a" in the case of a LIKE comparison of fixed-length fields.

To resolve this problem, append a percentage ("%") wildcard character to the parameter value ("a%"), or use an SQL = comparison instead.

Constructors

OdbcParameter()	Initializes a new instance of the OdbcParameter class.
OdbcParameter(String, Object)	Initializes a new instance of the OdbcParameter class that uses the parameter name and an OdbcParameter object.
OdbcParameter(String, OdbcType, Int32, ParameterDirection, Boolean, Byte, Byte, String, DataRowVersion, Object)	Initializes a new instance of the OdbcParameter class that uses the parameter name, data type, length, source column name, parameter direction, numeric precision, and other properties.
OdbcParameter(String, OdbcType, Int32, ParameterDirection, Byte, Byte, String, DataRowVersion, Boolean, Object)	Initializes a new instance of the OdbcParameter class that uses the parameter name, data type, length, source column name, parameter direction, numeric precision, and other properties.
OdbcParameter(String, OdbcType, Int32, String)	Initializes a new instance of the OdbcParameter class that uses the parameter name, data type, length, and source column name.
OdbcParameter(String, OdbcType, Int32)	Initializes a new instance of the OdbcParameter class that uses the parameter name, data type, and length.
OdbcParameter(String, OdbcType)	Initializes a new instance of the OdbcParameter class that uses the parameter name and data type.

Properties

DbType	Gets or sets the DbType of the parameter.
Direction	Gets or sets a value that indicates whether the parameter is input-only, output-only, bidirectional, or a stored procedure return value parameter.
IsNullable	Gets or sets a value that indicates whether the parameter accepts null values.
OdbcType	Gets or sets the OdbcType of the parameter.
ParameterName	Gets or sets the name of the OdbcParameter.
Precision	Gets or sets the number of digits used to represent the Value property.
Scale	Gets or sets the number of decimal places to which Value is resolved.
Size	Gets or sets the maximum size of the data within the column.
SourceColumn	Gets or sets the name of the source column mapped to the DataSet and used for loading or returning the Value.
SourceColumnNullMapping	Gets or sets a value which indicates whether the source column is nullable. This lets DbCommandBuilder correctly generate Update statements for nullable columns.
SourceVersion	Gets or sets the DataRowVersion to use when you load Value.
Value	Gets or sets the value of the parameter.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ResetDbType()	Resets the type associated with this OdbcParameter.
ResetOdbcType()	Resets the type associated with this OdbcParameter.
ToString()	Gets a string that contains the ParameterName.

Explicit Interface Implementations

ICloneable.Clone()

For a description of this member, see Clone().

See also

• Working with Commands