public override void Prepare(string commandText)
{
// Clear data
this.Clear();
this.parameters = null;
this.fields = null;
lock (this.db)
{
if (this.state == StatementState.Deallocated)
{
// Allocate statement
this.Allocate();
}
// Marshal structures to pointer
XsqldaMarshaler marshaler = XsqldaMarshaler.GetInstance();
// Setup fields structure
this.fields = new Descriptor(1);
IntPtr sqlda = marshaler.MarshalManagedToNative(this.db.Charset, this.fields);
int[] statusVector = FesConnection.GetNewStatusVector();
int trHandle = this.transaction.Handle;
int stmtHandle = this.handle;
byte[] buffer = this.db.Charset.GetBytes(commandText);
FbClient.isc_dsql_prepare(
statusVector,
ref trHandle,
ref stmtHandle,
(short)buffer.Length,
buffer,
this.db.Dialect,
sqlda);
// Marshal Pointer
Descriptor descriptor = marshaler.MarshalNativeToManaged(this.db.Charset, sqlda);
// Free memory
marshaler.CleanUpNativeData(ref sqlda);
// Parse status vector
this.db.ParseStatusVector(statusVector);
// Describe fields
this.fields = descriptor;
if (this.fields.ActualCount > 0 &&
this.fields.ActualCount != this.fields.Count)
{
this.Describe();
}
else
{
if (this.fields.ActualCount == 0)
{
this.fields = new Descriptor(0);
}
}
// Reset actual field values
this.fields.ResetValues();
// Get Statement type
this.statementType = this.GetStatementType();
// Update state
this.state = StatementState.Prepared;
}
}