public override void DescribeParameters()
{
lock (this.db)
{
// Marshal structures to pointer
XsqldaMarshaler marshaler = XsqldaMarshaler.GetInstance();
this.parameters = new Descriptor(1);
IntPtr sqlda = marshaler.MarshalManagedToNative(this.db.Charset, parameters);
int[] statusVector = FesConnection.GetNewStatusVector();
int stmtHandle = this.handle;
FbClient.isc_dsql_describe_bind(
statusVector,
ref stmtHandle,
IscCodes.SQLDA_VERSION1,
sqlda);
Descriptor descriptor = marshaler.MarshalNativeToManaged(this.db.Charset, sqlda);
// Parse status vector
this.db.ParseStatusVector(statusVector);
if (descriptor.ActualCount != 0 &&
descriptor.Count != descriptor.ActualCount)
{
short n = descriptor.ActualCount;
descriptor = new Descriptor(n);
// Fre memory
marshaler.CleanUpNativeData(ref sqlda);
// Marshal new structure
sqlda = marshaler.MarshalManagedToNative(this.db.Charset, descriptor);
FbClient.isc_dsql_describe_bind(
statusVector,
ref stmtHandle,
IscCodes.SQLDA_VERSION1,
sqlda);
descriptor = marshaler.MarshalNativeToManaged(this.db.Charset, sqlda);
// Free memory
marshaler.CleanUpNativeData(ref sqlda);
// Parse status vector
this.db.ParseStatusVector(statusVector);
}
else
{
if (descriptor.ActualCount == 0)
{
descriptor = new Descriptor(0);
}
}
// Free memory
if (sqlda != IntPtr.Zero)
{
marshaler.CleanUpNativeData(ref sqlda);
}
// Update parameter descriptor
this.parameters = descriptor;
}
}