// TODO: use switch expression, expression bodied member
public static bool Evaluate(BooleanComparisonType op, object left, object right)
{
switch (op)
{
case BooleanComparisonType.Equals:
return(left != null && left.Equals(right));
case BooleanComparisonType.NotEqualToBrackets:
case BooleanComparisonType.NotEqualToExclamation:
return(left == null || !left.Equals(right));
case BooleanComparisonType.GreaterThan:
// TODO: handle numeric conversions properly
if (left is int i && right is int j)
{
return(i > j);
}
if (left is decimal m && right is decimal n)
{
return(m > n);
}
return(string.Compare(left.ToString(), right.ToString()) > 0);
case BooleanComparisonType.GreaterThanOrEqualTo:
if (left is int i2 && right is int j2)
{
return(i2 >= j2);
}
if (left is decimal m2 && right is decimal n2)
{
return(m2 >= n2);
}
return(string.Compare(left.ToString(), right.ToString()) >= 0);
case BooleanComparisonType.LessThan:
if (left is int i3 && right is int j3)
{
return(i3 < j3);
}
if (left is decimal m3 && right is decimal n3)
{
return(m3 < n3);
}
return(string.Compare(left.ToString(), right.ToString()) < 0);
case BooleanComparisonType.LessThanOrEqualTo:
if (left is int i4 && right is int j4)
{
return(i4 <= j4);
}
if (left is decimal m4 && right is decimal n4)
{
return(m4 <= n4);
}
return(string.Compare(left.ToString(), right.ToString()) <= 0);
default:
throw FeatureNotSupportedException.Value(op);
}
}
private static Row CursorFetch(FetchCursorStatement fetch, Cursor cursor, Scope scope)
{
var orientation = fetch.FetchType?.Orientation ?? FetchOrientation.None;
switch (orientation)
{
case FetchOrientation.None:
case FetchOrientation.Next:
return(cursor.MoveNext());
case FetchOrientation.Prior:
return(cursor.MovePrior());
case FetchOrientation.First:
return(cursor.MoveFirst());
case FetchOrientation.Last:
return(cursor.MoveLast());
case FetchOrientation.Absolute:
return(cursor.MoveAbsolute(Evaluate <int>(fetch.FetchType?.RowOffset, NullArgument.It, scope)));
case FetchOrientation.Relative:
return(cursor.MoveRelative(Evaluate <int>(fetch.FetchType?.RowOffset, NullArgument.It, scope)));
default:
throw FeatureNotSupportedException.Value(orientation);
}
}
public static object Evaluate(AssignmentKind kind, object current, object value)
{
// TODO: use switch expression, expression bodied member
switch (kind)
{
case AssignmentKind.Equals:
return(value);
case AssignmentKind.AddEquals:
// TODO: handle numeric conversions properly
// TODO: and how do nulls work?
if (current == null || value == null)
{
return(current ?? value);
}
if (current is int i && value is int j)
{
return(i + j);
}
return((decimal)current + (decimal)value);
case AssignmentKind.SubtractEquals:
return((decimal)current - (decimal)value);
case AssignmentKind.MultiplyEquals:
return((decimal)current * (decimal)value);
case AssignmentKind.DivideEquals:
return((decimal)current / (decimal)value);
case AssignmentKind.ModEquals:
return((decimal)current % (decimal)value);
case AssignmentKind.BitwiseAndEquals:
return((int)current & (int)value);
case AssignmentKind.BitwiseOrEquals:
return((int)current | (int)value);
case AssignmentKind.BitwiseXorEquals:
return((int)current ^ (int)value);
default:
throw FeatureNotSupportedException.Value(kind);
}
}
public static object Evaluate(BinaryExpressionType op, object left, object right)
{
// TODO: use switch expression, expression bodied member
switch (op)
{
case BinaryExpressionType.Add:
// TODO: handle numeric conversions properly
if (left is string s && right is string t)
{
return(s + t);
}
if (left is int i && right is int j)
{
return(i + j);
}
return((int)left + (int)right);
case BinaryExpressionType.Subtract:
return((int)left - (int)right);
case BinaryExpressionType.Multiply:
return((int)left * (int)right);
case BinaryExpressionType.Divide:
return((int)left / (int)right);
case BinaryExpressionType.Modulo:
return((int)left % (int)right);
case BinaryExpressionType.BitwiseAnd:
return((int)left & (int)right);
case BinaryExpressionType.BitwiseOr:
return((int)left & (int)right);
case BinaryExpressionType.BitwiseXor:
return((int)left ^ (int)right);
default:
throw FeatureNotSupportedException.Value(op);
}
}
private static object GroupedFunctionCall(FunctionCall funCall, GroupArgument group, Scope scope)
{
var name = funCall.FunctionName.Value;
var paramCount = funCall.Parameters.Count;
var rows = group.Rows.Select(x => new RowArgument(x));
switch (name.ToLower())
{
case "sum" when paramCount == 1:
var expr0 = funCall.Parameters[0];
return(rows.Sum(x => Evaluate <int>(expr0, x, scope)));
case "avg" when paramCount == 1:
var expr1 = funCall.Parameters[0];
return(rows.Average(x => Evaluate <int>(expr1, x, scope)));
case "min" when paramCount == 1:
var expr2 = funCall.Parameters[0];
return(rows.Min(x => Evaluate <int>(expr2, x, scope)));
case "max" when paramCount == 1:
var expr3 = funCall.Parameters[0];
return(rows.Max(x => Evaluate <int>(expr3, x, scope)));
case "count" when paramCount == 1:
var expr4 = funCall.Parameters[0];
return(rows.Count(x => Evaluate(expr4, x, scope) != null));
case "count_big" when paramCount == 1:
var expr5 = funCall.Parameters[0];
return(rows.LongCount(x => Evaluate(expr5, x, scope) != null));
default:
throw FeatureNotSupportedException.Value(funCall);
}
}
public static EngineResult Evaluate(BinaryQueryExpressionType type, bool all, Table left, Table right, Env env)
{
// TODO: does offset/fetch/top happen before or after?
if (left.Columns.Count != right.Columns.Count)
{
throw new Exception("tables must have the same number of columns");
}
foreach (var i in Enumerable.Range(0, left.Columns.Count))
{
var a = left.Columns[i];
var b = right.Columns[i];
if (a.Name.Length > 0 && b.Name.Length > 0 && !a.Name.Last().Similar(b.Name.Last()))
{
throw new Exception("columns must have the same names");
}
// TODO: identify lowest common type
if (a.Type != b.Type)
{
throw new Exception("types must match");
}
}
var result = new Table {
Columns = left.Columns
};
bool Contains(Table t, Row r) =>
t.Rows.Any(s =>
Enumerable.Range(0, r.Columns.Count).All(i =>
Equality.Equal(r.Values[i], s.Values[i])));
switch (type)
{
case BinaryQueryExpressionType.Except:
foreach (var x in left.Rows)
{
if (!Contains(right, x) && (all || !Contains(result, x)))
{
result.AddCopy(x, env);
}
}
break;
case BinaryQueryExpressionType.Intersect:
foreach (var x in left.Rows)
{
if (Contains(right, x) && (all || !Contains(result, x)))
{
result.AddCopy(x, env);
}
}
if (all)
{
foreach (var x in right.Rows)
{
if (Contains(left, x))
{
result.AddCopy(x, env);
}
}
}
break;
case BinaryQueryExpressionType.Union:
foreach (var x in left.Rows)
{
if (all || !Contains(result, x))
{
result.AddCopy(x, env);
}
}
foreach (var x in right.Rows)
{
if (all || !Contains(result, x))
{
result.AddCopy(x, env);
}
}
break;
default:
throw FeatureNotSupportedException.Value(type);
}
return(new EngineResult(result));
}
// TODO: refactor how built-in functions are implemented
private static object UngroupedFunctionCall(FunctionCall funCall, IArgument arg, Scope scope)
{
var name = funCall.FunctionName.Value;
var paramCount = funCall.Parameters.Count;
// TODO: how to handle `select count(*)` ?
switch (name.ToLower())
{
case "error_number" when paramCount == 0:
return(scope.Env.ErrorNumber);
case "error_state" when paramCount == 0:
return(scope.Env.ErrorState);
case "error_message" when paramCount == 0:
return(scope.Env.ErrorMessage);
case "error_severity" when paramCount == 0:
return(null); // not properly implemented
case "error_line" when paramCount == 0:
return(null); // not properly implemented
case "error_procedure" when paramCount == 0:
return(null); // not properly implemented
case "isnumeric" when paramCount == 1:
var value = Evaluate(funCall.Parameters[0], arg, scope);
return(value != null && NumericTypes.Contains(value.GetType()) ? 1 : 0);
// TODO: not supported in version 8? see unit test
case "isnull" when paramCount == 2:
return(Evaluate <object>(funCall.Parameters[0], arg, scope)
?? Evaluate <object>(funCall.Parameters[1], arg, scope));
case "lower" when paramCount == 1:
return(Evaluate <string>(funCall.Parameters[0], arg, scope)?.ToLower());
case "upper" when paramCount == 1:
return(Evaluate <string>(funCall.Parameters[0], arg, scope)?.ToUpper());
case "trim" when paramCount == 1:
return(Evaluate <string>(funCall.Parameters[0], arg, scope)?.Trim());
case "ltrim" when paramCount == 1:
return(Evaluate <string>(funCall.Parameters[0], arg, scope)?.TrimStart());
case "rtrim" when paramCount == 1:
return(Evaluate <string>(funCall.Parameters[0], arg, scope)?.TrimEnd());
case "reverse" when paramCount == 1:
var s5 = Evaluate <string>(funCall.Parameters[0], arg, scope);
return(s5 == null ? null : new string(s5.Reverse().ToArray()));
case "substring" when paramCount == 3:
var s6 = Evaluate <string>(funCall.Parameters[0], arg, scope);
var i6 = Evaluate <int>(funCall.Parameters[1], arg, scope);
var j6 = Evaluate <int>(funCall.Parameters[2], arg, scope);
return(s6?.Substring(i6, j6));
case "dateadd":
Func <DateTime, int, DateTime> dateAdd = null;
switch (funCall.Parameters[0])
{
case ColumnReferenceExpression colExpr:
var dateUnit = colExpr.MultiPartIdentifier.Identifiers.LastOrDefault()?.Value?.ToLower();
// TODO: break this out into another function
switch (dateUnit)
{
case "year":
case "yy":
case "yyyy":
dateAdd = (d, x) => d.AddYears(x);
break;
case "quarter":
case "qq":
case "q":
dateAdd = (d, x) => d.AddMonths(x * 3);
break;
case "month":
case "mm":
case "m":
dateAdd = (d, x) => d.AddMonths(x);
break;
case "week":
case "wk":
case "ww":
dateAdd = (d, x) => d.AddDays(x * 7);
break;
case "dayofyear":
case "dy":
case "y":
case "weekday":
case "dw":
case "w":
case "day":
case "dd":
case "d":
dateAdd = (d, x) => d.AddDays(x);
break;
case "hour":
case "hh":
dateAdd = (d, x) => d.AddHours(x);
break;
case "minute":
case "mi":
case "n":
dateAdd = (d, x) => d.AddMinutes(x);
break;
case "second":
case "ss":
case "s":
dateAdd = (d, x) => d.AddSeconds(x);
break;
case "millisecond":
case "ms":
dateAdd = (d, x) => d.AddMilliseconds(x);
break;
default:
throw FeatureNotSupportedException.Value(dateUnit, "datepart");
}
break;
}
if (dateAdd == null)
{
throw new Exception("invalid DATEADD() time increment argument");
}
var x1 = Evaluate <int>(funCall.Parameters[1], arg, scope);
var d1 = Evaluate <DateTime>(funCall.Parameters[2], arg, scope);
return(dateAdd(d1, x1));
case "newid":
return(Guid.NewGuid());
default:
var env2 = scope.Env.Fork();
var f = scope.Env.Functions[name];
foreach (var(param, argExpr) in
f.Parameters.Zip(funCall.Parameters, (param, argExpr) => (param, argExpr)))
{
env2.Vars.Declare(param.Key, Evaluate(argExpr, arg, scope));
}
Evaluate(f.Statements, new Scope(env2));
return(env2.ReturnValue);
}
}