protected virtual ColumnAssignment VisitColumnAssignment(ColumnAssignment ca)
{
var c = (ColumnExpression)Visit(ca.Column);
Expression e = Visit(ca.Expression);
return(UpdateColumnAssignment(ca, c, e));
}
protected override Expression VisitUpdate(UpdateCommand update)
{
Write("UPDATE ");
WriteTableName(update.Table.Name);
WriteLine(Indentation.Same);
bool saveHide = HideColumnAliases;
HideColumnAliases = true;
Write("SET ");
for (int i = 0, n = update.Assignments.Count; i < n; i++)
{
ColumnAssignment ca = update.Assignments[i];
if (i > 0)
{
Write(", ");
}
Visit(ca.Column);
Write(" = ");
Visit(ca.Expression);
}
if (update.Where != null)
{
WriteLine(Indentation.Same);
Write("WHERE ");
VisitPredicate(update.Where);
}
HideColumnAliases = saveHide;
return(update);
}
protected override Expression VisitInsert(InsertCommand insert)
{
Write("INSERT INTO ");
WriteTableName(insert.Table.Name);
Write("(");
for (int i = 0, n = insert.Assignments.Count; i < n; i++)
{
ColumnAssignment ca = insert.Assignments[i];
if (i > 0)
{
Write(", ");
}
WriteColumnName(ca.Column.Name);
}
Write(")");
WriteLine(Indentation.Same);
Write("VALUES (");
for (int i = 0, n = insert.Assignments.Count; i < n; i++)
{
ColumnAssignment ca = insert.Assignments[i];
if (i > 0)
{
Write(", ");
}
Visit(ca.Expression);
}
Write(")");
return(insert);
}
protected ColumnAssignment UpdateColumnAssignment(ColumnAssignment ca, ColumnExpression c, Expression e)
{
if (c != ca.Column || e != ca.Expression)
{
return(new ColumnAssignment(c, e));
}
return(ca);
}
protected override ColumnAssignment VisitColumnAssignment(ColumnAssignment ca)
{
ca = base.VisitColumnAssignment(ca);
Expression expression = ca.Expression;
var nv = expression as NamedValueExpression;
if (nv != null)
{
expression = new NamedValueExpression(nv.Name, ca.Column.QueryType, nv.Value);
}
return(UpdateColumnAssignment(ca, ca.Column, expression));
}
protected virtual ReadOnlyCollection <ColumnAssignment> VisitColumnAssignments(ReadOnlyCollection <ColumnAssignment> assignments)
{
List <ColumnAssignment> alternate = null;
for (int i = 0, n = assignments.Count; i < n; i++)
{
ColumnAssignment assignment = VisitColumnAssignment(assignments[i]);
if (alternate == null && assignment != assignments[i])
{
alternate = assignments.Take(i).ToList();
}
if (alternate != null)
{
alternate.Add(assignment);
}
}
if (alternate != null)
{
return(alternate.AsReadOnly());
}
return(assignments);
}
