/// <summary>
/// Returns <see cref="DBNull"/>
/// when needed based on the specified type.
/// </summary>
/// <typeparam name="TypeOfValue">The specified type.</typeparam>
/// <param name="parameterValue">The boxed Parameter of the specified type.</param>
/// <param name="returnDbNullForZero">When true, return <see cref="DBNull"/> for numeric values.</param>
public static object GetParameterValue <TypeOfValue>(object parameterValue, bool returnDbNullForZero)
{
object o = parameterValue;
Type t = typeof(TypeOfValue);
if (parameterValue == null)
{
o = FrameworkTypeUtility.SqlDatabaseNull();
}
else if (t.Equals(typeof(DateTime)))
{
DateTime dt = (DateTime)parameterValue;
//CONVENTION: return DbNull for default DateTime (Jan 1900):
if (dt == default(DateTime))
{
o = FrameworkTypeUtility.SqlDatabaseNull();
}
}
else if (t.IsValueType)
{
if ((default(TypeOfValue).Equals(parameterValue)) && returnDbNullForZero)
{
o = FrameworkTypeUtility.SqlDatabaseNull();
}
}
return(o);
}
/// <summary>
/// Gets the parameter.
/// </summary>
/// <param name="dbmsCommand">The DBMS command.</param>
/// <param name="parameterMeta">The parameter meta.</param>
/// <returns></returns>
/// <exception cref="ArgumentNullException">
/// dbmsCommand;The expected Data Command is not here.
/// or
/// parameterMeta;The expected parameter metadata is not here.
/// </exception>
public static IDataParameter GetParameterFromParameterMetadata(IDbCommand dbmsCommand, DataParameterMetadata parameterMeta)
{
if (dbmsCommand == null)
{
throw new ArgumentNullException("dbmsCommand", "The expected Data Command is not here.");
}
if (parameterMeta == null)
{
throw new ArgumentNullException("parameterMeta", "The expected parameter metadata is not here.");
}
IDataParameter param = dbmsCommand.CreateParameter();
param.ParameterName = parameterMeta.ParameterName;
param.DbType = parameterMeta.DbType;
param.Direction = parameterMeta.ParameterDirection;
param.SourceColumn = parameterMeta.SourceColumn;
param.SourceVersion = parameterMeta.DataRowVersion;
param.Value = parameterMeta.ParameterValue ?? FrameworkTypeUtility.SqlDatabaseNull();
return(param);
}
/// <summary>
/// Gets an array of objects implementing <see cref="IDataParameter"/>.
/// </summary>
/// <param name="dbmsCommand">The object implementing <see cref="IDbCommand"/>.</param>
/// <param name="parameterCollection">A collection of parameters.</param>
/// <returns>Returns an array of objects implementing <see cref="IDataParameter"/>.</returns>
/// <remarks>
/// Supported collections:
/// IEnumerable<IDataParameter> [pass-through]
/// IEnumerable<DataParameterMetadata>
/// Dictionary<string, object>
/// </remarks>
public static IDataParameter[] GetParameters(IDbCommand dbmsCommand, IEnumerable parameterCollection)
{
if (parameterCollection == null)
{
throw new ArgumentNullException("parameterCollection", "The expected set of parameters is not here.");
}
var @default = parameterCollection as IEnumerable <IDataParameter>;
if (@default != null)
{
return(parameterCollection.OfType <IDataParameter>().ToArray());
}
var m = parameterCollection as IEnumerable <DataParameterMetadata>;
if (m != null)
{
return(m.Select(i => GetParameterFromParameterMetadata(dbmsCommand, i)).ToArray());
}
var d = parameterCollection as Dictionary <string, object>;
if (d != null)
{
return(d.Select(i => GetParameter(dbmsCommand, i.Key, i.Value ?? FrameworkTypeUtility.SqlDatabaseNull())).ToArray());
}
throw new NotSupportedException(@"
The parameter collection is not supported.
Supported collections:
IEnumerable<IDataParameter> [pass-through]
IEnumerable<DataParameterMetadata>
Dictionary<string, object>
");
}
