protected override Expression VisitDeclaration(DbDeclarationCommand decl)
{
if (decl.Source != null)
{
var projection = new DbProjectionExpression
(
decl.Source,
Expression.NewArrayInit(typeof(object), decl.Variables.Select(v => v.Expression.Type.GetTypeInfo().IsValueType ? Expression.Convert(v.Expression, typeof(object)) : v.Expression).ToArray()),
DbAggregator.GetAggregator(typeof(object[]), typeof(IEnumerable <object[]>))
);
var vars = Expression.Parameter(typeof(object[]), "vars");
this.variables.Add(vars);
this.initializers.Add(Expression.Constant(null, typeof(object[])));
for (int i = 0, n = decl.Variables.Count; i < n; i++)
{
var v = decl.Variables[i];
var nv = new DbNamedValueExpression
(
v.Name, v.QueryType,
Expression.Convert(Expression.ArrayIndex(vars, Expression.Constant(i)), v.Expression.Type)
);
this.variableMap.Add(v.Name, nv);
}
return(MakeAssign(vars, this.Visit(projection)));
}
throw new InvalidOperationException("Declaration query not allowed for this langauge");
}
protected override DbColumnAssignment VisitColumnAssignment(DbColumnAssignment ca)
{
ca = base.VisitColumnAssignment(ca);
var expression = ca.Expression;
if (expression is DbNamedValueExpression nv)
{
expression = new DbNamedValueExpression(nv.Name, ca.Column.QueryType, nv.Value);
}
return(this.UpdateColumnAssignment(ca, ca.Column, expression));
}
private Expression GetNamedValue(Expression e)
{
var he = new HashedExpression(e);
if (this.pmap.TryGetValue(he, out DbNamedValueExpression nv) == false)
{
var name = "p" + (iParam++);
nv = new DbNamedValueExpression(name, this.language.TypeSystem.GetColumnType(e.Type), e);
this.pmap.Add(he, nv);
}
return(nv);
}
protected override Expression VisitConstant(ConstantExpression c)
{
if (c.Value != null && !IsNumeric(c.Value.GetType()))
{
var tv = new TypeAndValue(c.Type, c.Value);
if (this.map.TryGetValue(tv, out DbNamedValueExpression nv) == false)
{
var name = "p" + (iParam++);
nv = new DbNamedValueExpression(name, this.language.TypeSystem.GetColumnType(c.Type), c);
this.map.Add(tv, nv);
}
return(nv);
}
return(c);
}
protected override Expression VisitBinary(BinaryExpression b)
{
var left = this.Visit(b.Left);
var right = this.Visit(b.Right);
if (left.NodeType == (ExpressionType)DbExpressionType.NamedValue && right.NodeType == (ExpressionType)DbExpressionType.Column)
{
var nv = left as DbNamedValueExpression;
var c = right as DbColumnExpression;
left = new DbNamedValueExpression(nv.Name, c.QueryType, nv.Value);
}
else if (right.NodeType == (ExpressionType)DbExpressionType.NamedValue && left.NodeType == (ExpressionType)DbExpressionType.Column)
{
var nv = right as DbNamedValueExpression;
var c = left as DbColumnExpression;
right = new DbNamedValueExpression(nv.Name, c.QueryType, nv.Value);
}
return(this.UpdateBinary(b, left, right, b.Conversion, b.IsLiftedToNull, b.Method));
}
protected virtual bool CompareNamedValue(DbNamedValueExpression a, DbNamedValueExpression b)
{
return(a.Name == b.Name && this.Compare(a.Value, b.Value));
}
protected override Expression VisitNamedValue(DbNamedValueExpression value)
{
this.WriteParameterName(value.Name);
return(value);
}
protected virtual Expression VisitNamedValue(DbNamedValueExpression value)
{
return(value);
}
protected override Expression VisitNamedValue(DbNamedValueExpression value)
{
this.namedValues.Add(value);
return(value);
}
