protected override Expression VisitMemberAccess(MemberExpression m)
{
m = (MemberExpression)base.VisitMemberAccess(m);
NamedValueExpression nv = m.Expression as NamedValueExpression;
if (nv != null)
{
Expression x = Expression.MakeMemberAccess(nv.Value, m.Member);
return(GetNamedValue(x));
}
return(m);
}
private Expression GetNamedValue(Expression e)
{
NamedValueExpression nv;
HashedExpression he = new HashedExpression(e);
if (!this.pmap.TryGetValue(he, out nv))
{
string name = "p" + (iParam++);
nv = new NamedValueExpression(name, SqlType.Get(e.Type), e);
this.pmap.Add(he, nv);
}
return(nv);
}
protected override ColumnAssignment VisitColumnAssignment(ColumnAssignment ca)
{
ca = base.VisitColumnAssignment(ca);
Expression expression = ca.Expression;
NamedValueExpression nv = null;
if (expression.NodeType == ExpressionType.Constant)
{
var value = (expression as ConstantExpression).Value;
if (value == null)
{
TypeAndValue tv = new TypeAndValue(ca.Column.Type, null);
if (!this.map.TryGetValue(tv, out nv))
{
string name = "p" + (iParam++);
nv = new NamedValueExpression(name, SqlType.Get(ca.Column.Type), Expression.Constant(null, ca.Column.Type));
this.map.Add(tv, nv);
}
expression = nv;
}
else
{
var columnType = ca.Column.Type;
if (columnType.IsNullable())
{
columnType = Nullable.GetUnderlyingType(columnType);
}
if (columnType != value.GetType())
{
value = Converter.Convert(value, columnType);
expression = Expression.Constant(value);
}
}
}
nv = expression as NamedValueExpression;
if (nv != null)
{
expression = new NamedValueExpression(nv.Name, ca.Column.SqlType, nv.Value);
}
return(this.UpdateColumnAssignment(ca, ca.Column, expression));
}
protected override Expression VisitBinary(BinaryExpression b)
{
Expression left = this.Visit(b.Left);
Expression right = this.Visit(b.Right);
if (left.NodeType == (ExpressionType)DbExpressionType.NamedValue &&
right.NodeType == (ExpressionType)DbExpressionType.Column)
{
NamedValueExpression nv = (NamedValueExpression)left;
ColumnExpression c = (ColumnExpression)right;
left = new NamedValueExpression(nv.Name, c.SqlType, nv.Value);
}
else if (right.NodeType == (ExpressionType)DbExpressionType.NamedValue &&
left.NodeType == (ExpressionType)DbExpressionType.Column)
{
NamedValueExpression nv = (NamedValueExpression)right;
ColumnExpression c = (ColumnExpression)left;
right = new NamedValueExpression(nv.Name, c.SqlType, nv.Value);
}
return(this.UpdateBinary(b, left, right, b.Conversion, b.IsLiftedToNull, b.Method));
}
protected override Expression VisitConstant(ConstantExpression c)
{
if (c.Value != null)
{
var type = c.Value.GetType();
if (/*!IsNumeric(type) && type != Types.TimeSpan &&*/ c.Type != typeof(Type))
{
NamedValueExpression nv;
TypeAndValue tv = new TypeAndValue(type, c.Value);
if (!this.map.TryGetValue(tv, out nv))
{
string name = "p" + (iParam++);
nv = new NamedValueExpression(name, SqlType.Get(type), c);
this.map.Add(tv, nv);
}
return(nv);
}
//else
//{
//}
}
return(c);
}
protected virtual bool CompareNamedValue(NamedValueExpression a, NamedValueExpression b)
{
return(a.Name == b.Name && this.Compare(a.Value, b.Value));
}
protected override Expression VisitNamedValue(NamedValueExpression value)
{
this.namedValues.Add(value);
return(value);
}
protected virtual Expression VisitNamedValue(NamedValueExpression value)
{
return(value);
}