public Exp Convert( DataType t )
{
if ( t < DataType.Decimal ) t = DTI.Base( t );
if ( Type == t ) return this;
else if ( Type == DataType.Bigint ) return
t == DataType.String ? (Exp) new IntToStringExp( this )
: t == DataType.Double ? (Exp) new IntToDoubleExp( this )
: t >= DataType.Decimal ? (Exp) new IntToDecimalExp( this, t )
: null;
else if ( Type == DataType.Double ) return
t == DataType.String ? (Exp) new DoubleToStringExp( this )
: t == DataType.Bigint ? (Exp) new DoubleToIntExp( this )
: t >= DataType.Decimal ? (Exp) new DoubleToDecimalExp( this, t )
: null;
else if ( Type >= DataType.Decimal )
{
if ( t == DataType.String ) return new DecimalToStringExp( this );
else if ( t == DataType.Double ) return new DecimalToDoubleExp( this );
else if ( t >= DataType.Decimal )
{
int amount = DTI.Scale( t ) - DTI.Scale( Type );
return amount == 0 ? (Exp) this
: amount > 0 ? (Exp) new ExpScale( this, t, amount )
: (Exp) new ExpScaleReduce( this, t, -amount );
}
}
else if ( Type == DataType.Binary && t == DataType.String )
return new BinaryToStringExp( this );
else if ( Type == DataType.Bool && t == DataType.String )
return new BoolToStringExp( this );
else if ( Type == DataType.ScaledInt && t >= DataType.Decimal ) return this;
return null;
}
// At least one of GetDV or the relevant GetD? must be implemented ( or an infinite recursion will happen ).
public virtual DV GetDV()
{
switch( DTI.Base( Type ) )
{
case DataType.Bool : DB db = GetDB(); return ( ee ) => Value.New( db( ee ) );
case DataType.Double : DD dd = GetDD(); return ( ee ) => Value.New( dd( ee ) );
case DataType.String : DS ds = GetDS(); return ( ee ) => Value.New( ds( ee ) );
case DataType.Binary : DX dx = GetDX(); return ( ee ) => Value.New( dx( ee ) );
default: DL dl = GetDL(); return ( ee ) => Value.New( dl( ee ) );
}
}
public override void Bind( SqlExec e )
{
var ci = e.CI;
if ( ci == null ) e.Error( "Undeclared variable " + ColName );
for ( int i=0; i < ci.Count; i += 1 )
if ( ci.Name[ i ] == ColName )
{
e.Used[ i ] = true;
ColIx = i;
Type = DTI.Base( ci.Type[ i ] );
return;
}
e.Error( "Column " + ColName + " not found" );
}
public override DataType Bind( SqlExec e )
{
var ci = e.CI;
if ( ci == null ) e.Error( "Undeclared variable " + ColName );
for ( int i=0; i < ci.Count; i += 1 )
if ( ci.Names[i] == ColName )
{
e.Used[ i ] = true;
ColIx = i;
Type = DTI.Base( ci.Types[i] );
return Type;
}
// for ( int i=0; i < ci.Length; i += 1 ) System.Console.WriteLine( ci[i].Name );
e.Error( "Column " + ColName + " not found" );
return Type;
}
