DataDirect Connect for ADO.NET Data Provider Help

Provider-specific Classes

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Provider-specific Classes

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Last Updated: April 16, 2026
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ADO.NET
Documentation

DataDirect Connect for ADO.NET data providers support all of the .NET public classes.

In addition, some of the data providers define additional properties and methods. For information on additional properties and methods that have been defined, see:

See the section for each data provider for the supported public objects, properties, and methods. Each data provider attaches a provider-specific prefix to the names of the public class, for example, OracleConnection or SybaseCommand.

For more information on public objects, refer to the Microsoft .NET Framework SDK documentation.

For information about using bulk copy and other enhanced features of the DataDirect Connect for ADO.NET data providers, see DataDirect Classes.

For all of the data providers, the result set produced for PrefixDataReader.GetSchemaTable() returns the columns described in the following table, in the order shown, where Prefix is the identifier for the data provider, for example, DB2DataReader.GetSchemaTable().

Columns Returned by GetSchemaTable on DataReader

Column	Description
ColumnName	Specifies the name of the column, which might not be unique. If the name cannot be determined, a null value is returned. This name reflects the most recent renaming of the column in the current view or command text.
ColumnOrdinal	Specifies the ordinal of the column, which cannot be null. The bookmark column of the row, if any, is 0. Other columns are numbered starting with 1.
ColumnSize	Specifies the maximum possible length of a value in the column. For columns that use a fixed-length data type, this is the size of the data type.
NumericPrecision	Specifies the precision of the column, which depends on how the column is defined in ProviderType. If ProviderType is a numeric data type, this is the maximum precision of the column. If ProviderType is not a numeric data type, the value is null.
NumericScale	Specifies the number of digits to the right of the decimal point if ProviderType is DBTYPE_DECIMAL or DBTYPE_NUMERIC. Otherwise, this is a null value. The value depends on how the column is defined in ProviderType.
DataType	Maps to the .NET Framework type of the column.
ProviderType	Specifies the indicator of the column's data type. This column cannot contain a null value. If the data type of the column varies from row to row, this must be Object.
IsLong	Set if the column contains a BLOB that contains very long data. The setting of this flag corresponds to the value of the IS_LONG column in the PROVIDER_TYPES rowset for the data type. The definition of very long data is provider-specific.
AllowDBnull	Set if the consumer can set the column to a null value, or if the data provider cannot determine whether or not the consumer can set the column to a null value. Otherwise, no value is set. A column can contain null values, even if it cannot be set to a null value.
IsReadOnly	Determines whether a column can be changed. The value is true if the column can be modified; otherwise, the value is false.
IsRowVersion	Is set if the column contains a persistent row identifier that cannot be written to, and has no meaningful value except to identify the row.
IsUnique	Specifies whether the column constitutes a key by itself or if there is a constraint of type UNIQUE that applies only to this column. When set to true, no two rows in the base table (the table returned in BaseTableName) can have the same value in this column. When set to false (the initial default), the column can contain duplicate values in the base table.
IsKey	Specifies whether a set of columns uniquely identifies a row in the rowset. This set of columns may be generated from a base table primary key, a unique constraint, or a unique index. The value is true if the column is one of a set of columns in the rowset that, taken together, uniquely identify the row. The value is false if the column is not required to uniquely identify the row.
IsAutoIncrement	Specifies whether the column assigns values to new rows in fixed increments. When set to VARIANT_TRUE, the column assigns values to new rows in fixed increments. When set to VARIANT_FALSE (the initial default), the column does not assign values to new rows in fixed increments.
BaseSchemaName	Specifies the name of the schema in the database that contains the column. The value is null if the base schema name cannot be determined. The initial default is null.
BaseCatalogName	Specifies the name of the catalog in the data store that contains the column. A null value is used if the base catalog name cannot be determined. The initial default is null.
BaseTableName	Specifies the name of the table or view in the data store that contains the column. A null value is used if the base table name cannot be determined. The initial default is null.
BaseColumnName	Specifies the name of the column in the data store. This might be different than the column name returned in the ColumnName column if an alias was used. A null value is used if the base column name cannot be determined or if the rowset column is derived from, but is not identical to, a column in the database. The initial default is null.
IsAliased	Specifies whether the name of the column is an alias. The value true is returned if the column name is an alias; otherwise false is returned.
IsExpression	Specifies whether the name of the column is an expression. The value true is returned if the column is an expression; otherwise false is returned.
IsIdentity	Specifies whether the name of the column is an identity column. The value true is returned if the column is an identity column; otherwise false is returned.
IsHidden	Specifies whether the name of the column is hidden. The value true is returned if the column is hidden; otherwise false is returned.