protected override Expression VisitUnary(UnaryExpression unaryExpression)
{
Check.NotNull(unaryExpression, nameof(unaryExpression));
if (unaryExpression.NodeType == ExpressionType.ArrayLength &&
unaryExpression.Operand.Type == typeof(byte[]))
{
return(base.Visit(unaryExpression.Operand) is SqlExpression sqlExpression
? SqlExpressionFactory.Function("length", new[] { sqlExpression }, typeof(int))
: null);
}
var visitedExpression = base.VisitUnary(unaryExpression);
if (visitedExpression == null)
{
return(null);
}
if (visitedExpression is SqlUnaryExpression sqlUnary &&
sqlUnary.OperatorType == ExpressionType.Negate)
{
var operandType = GetProviderType(sqlUnary.Operand);
if (operandType == typeof(decimal) ||
operandType == typeof(TimeSpan))
{
return(null);
}
}
return(visitedExpression);
}
protected override Expression VisitUnary(UnaryExpression unaryExpression)
{
if (unaryExpression.NodeType == ExpressionType.ArrayLength &&
unaryExpression.Operand.Type == typeof(byte[]))
{
var sqlExpression = base.Visit(unaryExpression.Operand) as SqlExpression;
if (sqlExpression == null)
{
return(null);
}
var isBinaryMaxDataType = GetProviderType(sqlExpression) == "varbinary(max)" || sqlExpression is SqlParameterExpression;
var dataLengthSqlFunction = SqlExpressionFactory.Function(
"DATALENGTH",
new[] { sqlExpression },
nullable: true,
argumentsPropagateNullability: new bool[] { true },
isBinaryMaxDataType ? typeof(long) : typeof(int));
return(isBinaryMaxDataType
? (Expression)SqlExpressionFactory.Convert(dataLengthSqlFunction, typeof(int))
: dataLengthSqlFunction);
}
return(base.VisitUnary(unaryExpression));
}
public override SqlExpression TranslateLongCount(Expression expression = null)
{
if (expression != null)
{
// TODO: Translate Count with predicate for GroupBy
return(null);
}
return(SqlExpressionFactory.ApplyDefaultTypeMapping(
SqlExpressionFactory.Function("COUNT_BIG", new[] { SqlExpressionFactory.Fragment("*") }, typeof(long))));
}
public override SqlExpression TranslateLongCount(Expression expression = null)
{
if (expression != null)
{
// TODO: Translate Count with predicate for GroupBy
return(null);
}
return(SqlExpressionFactory.ApplyDefaultTypeMapping(
SqlExpressionFactory.Function(
"COUNT_BIG",
new[] { SqlExpressionFactory.Fragment("*") },
nullResultAllowed: true,
argumentsPropagateNullability: new[] { false },
typeof(long))));
}
private Expression DoDecimalCompare(SqlExpression visitedExpression, ExpressionType op, SqlExpression left, SqlExpression right)
{
var actual = SqlExpressionFactory.Function(
name: "ef_compare",
new[] { left, right },
nullable: true,
new[] { true, true },
typeof(int));
var oracle = SqlExpressionFactory.Constant(value: 0);
return(op switch
{
ExpressionType.GreaterThan => SqlExpressionFactory.GreaterThan(left: actual, right: oracle),
ExpressionType.GreaterThanOrEqual => SqlExpressionFactory.GreaterThanOrEqual(left: actual, right: oracle),
ExpressionType.LessThan => SqlExpressionFactory.LessThan(left: actual, right: oracle),
ExpressionType.LessThanOrEqual => SqlExpressionFactory.LessThanOrEqual(left: actual, right: oracle),
_ => visitedExpression
});
protected override Expression VisitBinary(BinaryExpression binaryExpression)
{
Check.NotNull(binaryExpression, nameof(binaryExpression));
var visitedExpression = (SqlExpression)base.VisitBinary(binaryExpression);
if (visitedExpression == null)
{
return(null);
}
if (visitedExpression is SqlBinaryExpression sqlBinary)
{
if (sqlBinary.OperatorType == ExpressionType.Modulo &&
(_functionModuloTypes.Contains(GetProviderType(sqlBinary.Left)) ||
_functionModuloTypes.Contains(GetProviderType(sqlBinary.Right))))
{
return(SqlExpressionFactory.Function(
"ef_mod",
new[] { sqlBinary.Left, sqlBinary.Right },
nullable: true,
argumentsPropagateNullability: new[] { true, true },
visitedExpression.Type,
visitedExpression.TypeMapping));
}
if (AttemptDecimalCompare(sqlBinary))
{
return(DoDecimalCompare(visitedExpression, sqlBinary.OperatorType, sqlBinary.Left, sqlBinary.Right));
}
if (_restrictedBinaryExpressions.TryGetValue(sqlBinary.OperatorType, out var restrictedTypes) &&
(restrictedTypes.Contains(GetProviderType(sqlBinary.Left)) ||
restrictedTypes.Contains(GetProviderType(sqlBinary.Right))))
{
return(null);
}
}
return(visitedExpression);
}