private static void CorrectExpression(ref ExpressionOperator oper, ref int num1, ref int num2, int resultMax)
{
switch (oper)
{
case ExpressionOperator.Add:
if (num1 + num2 > resultMax)
{
oper = ExpressionOperator.Subtract;
if (num1 < num2)
{
int temp = num1;
num1 = num2;
num2 = temp;
}
}
break;
case ExpressionOperator.Subtract:
if (num1 < num2)
{
int temp = num1;
num1 = num2;
num2 = temp;
}
break;
case ExpressionOperator.Multiply:
break;
case ExpressionOperator.Divide:
break;
}
}
protected internal ODataExpression(ODataExpression expression)
{
_functionCaller = expression._functionCaller;
_left = expression._left;
_right = expression._right;
_operator = expression._operator;
_conversionType = expression._conversionType;
this.Reference = expression.Reference;
this.ReferenceScope = expression.ReferenceScope;
this.Value = expression.Value;
this.Function = expression.Function;
}
private static string OperatorToString(ExpressionOperator oper)
{
string strOper = "";
switch (oper)
{
case ExpressionOperator.Add:
strOper = "+";
break;
case ExpressionOperator.Subtract:
strOper = "-";
break;
case ExpressionOperator.Multiply:
strOper = "*";
break;
case ExpressionOperator.Divide:
strOper = "/";
break;
}
return strOper;
}
private static string ConvertToWords(ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.Addition:
return("Add");
case ExpressionOperator.And:
return("And");
case ExpressionOperator.Constant:
return("Constant");
case ExpressionOperator.ConvertToInt32:
return("Int32");
case ExpressionOperator.ConvertToFloat32:
return("Single");
case ExpressionOperator.ConvertToFloat64:
return("Double");
case ExpressionOperator.ConvertToUInt16:
return("UInt16");
case ExpressionOperator.ConvertToUInt32:
return("UInt32");
case ExpressionOperator.ConvertToUInt8:
return("UInt8");
case ExpressionOperator.Division:
return("Div");
case ExpressionOperator.Equal:
return("Eq");
case ExpressionOperator.Equal_Obj:
return("Eq_obj");
case ExpressionOperator.GreaterEqualThan:
return("Cge");
case ExpressionOperator.GreaterEqualThan_Un:
return("Cge_un");
case ExpressionOperator.GreaterThan:
return("Cgt");
case ExpressionOperator.GreaterThan_Un:
return("Cgt_un");
case ExpressionOperator.LessEqualThan:
return("Cle");
case ExpressionOperator.LessEqualThan_Un:
return("Cle_un");
case ExpressionOperator.LessThan:
return("Clt");
case ExpressionOperator.LessThan_Un:
return("Clt_un");
case ExpressionOperator.LogicalAnd:
return("And");
case ExpressionOperator.LogicalNot:
return("Not");
case ExpressionOperator.LogicalOr:
return("Or");
case ExpressionOperator.Modulus:
return("Rem");
case ExpressionOperator.Multiplication:
return("Mul");
case ExpressionOperator.Not:
return("Not");
case ExpressionOperator.NotEqual:
return("Neq");
case ExpressionOperator.Or:
return("Or");
case ExpressionOperator.Xor:
return("Xor");
case ExpressionOperator.ShiftLeft:
return("Shl");
case ExpressionOperator.ShiftRight:
return("Shr");
case ExpressionOperator.SizeOf:
return("Sizeof");
case ExpressionOperator.Subtraction:
return("Sub");
case ExpressionOperator.UnaryMinus:
return("Minus");
case ExpressionOperator.Unknown:
return("???");
case ExpressionOperator.Variable:
return("Var");
case ExpressionOperator.WritableBytes:
return("WB");
default:
return("???");
}
}
public static void Rule(Expression result, Expression expression, ExpressionOperator op, Term term)
{
result.Value = op.Function(expression.Value, term.Value);
}
/// <summary>
/// Compares with expression
/// </summary>
/// <param name="expressionValue">Expression to compare with</param>
/// <param name="op">Operator</param>
/// <returns>Boolean expression</returns>
public override TypedExpressionValue <bool> Compare(ExpressionValue expressionValue, ExpressionOperator op)
{
if (ValidCompare(expressionValue, op))
{
if (expressionValue.Type == typeof(double))
{
return(CompareValue(expressionValue as TypedExpressionValue <double>, op));
}
else if (expressionValue.Type == typeof(int))
{
return(CompareValue(expressionValue as ExpressionInt, op)); // Uses implicit cast
}
}
throw new InvalidOperationException(UserMessages.ExceptionNoComparison(Type, expressionValue.Type, op));
}
public ExpressionOperatorEntry(ExpressionOperator oper, int start, int end)
{
this.oper = oper;
this.start = start;
this.end = end;
priority = -1;
}
public ValueProcessor(List <string> operands, ExpressionOperator operators)
{
_operands = operands;
_operators = operators;
}
public DefaultExpressionValuesAttribute(ExpressionOperator oper, double value)
{
Operator = oper;
Value = value;
}
public static void GetLeftRightOperatorsForBetween(bool includeLeft, bool includeRight
, out ExpressionOperator leftOp, out ExpressionOperator rightOp)
{
leftOp = includeLeft ? ExpressionOperator.GreaterThanOrEquals : ExpressionOperator.GreaterThan;
rightOp = includeRight ? ExpressionOperator.LessThanOrEquals : ExpressionOperator.LessThan;
}
public abstract TypedExpressionValue <bool> Compare(ExpressionValue expressionValue, ExpressionOperator op);
/// <summary>
///
/// </summary>
/// <param name="fieldName"></param>
/// <param name="expressionOperator"></param>
/// <param name="fieldValue"></param>
public FilterExpression(string fieldName, ExpressionOperator expressionOperator, string fieldValue)
{
FieldName = fieldName;
ExpressionOperator = expressionOperator;
FieldValue = fieldValue;
}
/// <summary>
/// Adds expression and operator to the respective chains
/// </summary>
/// <param name="expression">Expression to add</param>
/// <param name="op">Operator to add</param>
protected void AddToChain(Func <T> expression, ExpressionOperator op)
{
_expressionChain.Add(expression);
_operatorChain.Add(op);
}
public abstract ExpressionValue Combine(ExpressionValue expressionValue, ExpressionOperator op);
/// <summary>
/// Checks if a comparison is possible
/// </summary>
/// <param name="expressionValue">Expression to compare with</param>
/// <param name="op">Comparison operator</param>
/// <returns>Is valid comparison</returns>
protected bool ValidCompare(ExpressionValue expressionValue, ExpressionOperator op)
{
return(ExpressionOperators.Comparison.Contains(op) && CompatibleOperators.Contains(op));
}
/// <summary>
/// Checks if combination is possible
/// </summary>
/// <param name="expressionValue">Expression to combine with</param>
/// <param name="op">Operators for expression</param>
/// <returns>Is valid combination</returns>
protected bool ValidCombine(ExpressionValue expressionValue, ExpressionOperator op)
{
return(CompatibleTypes.Contains(expressionValue.Type) && CompatibleOperators.Contains(op));
}
/// <summary> /// Combine expressions with eachother /// </summary> /// <param name="expression1">Left hand side expression</param> /// <param name="expression2">Right hand side expression</param> /// <param name="op">Operator</param> /// <returns>Resulting expression</returns> protected abstract Func <T> CombineExpressions(Func <T> expression1, Func <T> expression2, ExpressionOperator op);
public static string ExceptionNoCombination(ExpressionType type1, ExpressionType type2, ExpressionOperator expressionOperator)
{
return(string.Format("Combination of {0} and {1} not implemented for operator {2}", type1, type2, expressionOperator));
}
Expression IExpressionEncoder <Variable, Expression> .CompoundExpressionFor(ExpressionType type, ExpressionOperator op, Expression left, Expression right)
{
Contract.Ensures(Contract.Result <Expression>() != null);
throw new System.NotImplementedException();
}
public override TypedExpressionValue <bool> Compare(ExpressionValue expressionValue, ExpressionOperator op)
{
if (ValidCompare(expressionValue, op))
{
switch (expressionValue)
{
case IExpressionNumeric numericExpression:
return(NumericUtils.Compare(this, numericExpression, op));
default:
throw new NotImplementedException();
}
throw new NotImplementedException();
}
throw new InvalidOperationException(UserMessages.ExceptionNoComparison(ExpressionType, expressionValue.ExpressionType, op));
}
public override Interval ApplyConversion(ExpressionOperator conv, Interval intv)
{
return(Interval.ApplyConversion(conv, intv));
}
/// <summary>
/// Combines two expressions
/// </summary>
/// <param name="item1">Left hand side</param>
/// <param name="item2">Right hand side</param>
/// <param name="op">Operator</param>
/// <returns>Resulting delegate</returns>
protected override Func <double> CombineExpressions(Func <double> item1, Func <double> item2, ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.Plus:
return(() => item1() + item2());
case ExpressionOperator.Minus:
return(() => item1() - item2());
case ExpressionOperator.Multiply:
return(() => item1() * item2());
case ExpressionOperator.Divide:
return(() => item1() / item2());
}
throw new InvalidOperationException(UserMessages.ExceptionNoCombination(Type, Type, op));
}
/// <summary>
/// Creates a binary lambda expression that represents a comparison operation between a property
/// of <typeparamref name="T"/> and the provided value using the specified comparison operator.
/// </summary>
/// <typeparam name="T">
/// The type that contains the property to be compared.
/// </typeparam>
/// <param name="propertyInfo">
/// The metadata of the property to be compared.
/// </param>
/// <param name="value">
/// The value to compare the property.
/// </param>
/// <param name="operator">
/// The comparison operator.
/// </param>
/// <returns>A <see cref="Expression{TDelegate}"/> representing the comparison operation.</returns>
public static Expression <Func <T, bool> > CreateBinary <T>(PropertyInfo propertyInfo, object value, ExpressionOperator @operator)
{
return(BuildBinaryExpression <T>(propertyInfo.Name, value, @operator));
}
private static double CalculateOperator(ExpressionOperator op, double a, double b)
{
switch (op)
{
case ExpressionOperator.Equal:
return a == b ? 1 : 0;
case ExpressionOperator.NotEqual:
return a != b ? 1 : 0;
case ExpressionOperator.And:
return a != 0 && b != 0 ? 1 : 0;
case ExpressionOperator.Div:
{
if (b == 0) throw new Exception("Division by 0");
return a / b;
}
case ExpressionOperator.Greater:
return a > b ? 1 : 0;
case ExpressionOperator.Log:
return Math.Log(b);
case ExpressionOperator.Log10:
return Math.Log10(b);
case ExpressionOperator.Lower:
return a < b ? 1 : 0;
case ExpressionOperator.Minus:
return a - b;
case ExpressionOperator.Mult:
return a * b;
case ExpressionOperator.SignInversion:
return -b;
case ExpressionOperator.Or:
return a != 0 || b != 0 ? 1 : 0;
case ExpressionOperator.Plus:
return a + b;
case ExpressionOperator.Pow:
return Math.Pow(a, b);
case ExpressionOperator.Sign:
return Math.Sign(b);
case ExpressionOperator.Cos:
return Math.Cos(b);
case ExpressionOperator.Sin:
return Math.Sin(b);
case ExpressionOperator.Tan:
return Math.Tan(b);
case ExpressionOperator.ReplaceNil:
return a == 0 ? b : a;
case ExpressionOperator.Negate:
return b == 0 ? 1 : 0;
}
return 0;
}
/// <summary>
/// Creates a binary lambda expression that represents a comparison operation between a property
/// of <typeparamref name="T"/> and the provided value using the specified comparison operator.
/// </summary>
/// <typeparam name="T">
/// The type that contains the property to be compared.
/// </typeparam>
/// <param name="propertyNameOrPath">
/// The name or the path to the property.
/// </param>
/// <param name="value">
/// The value to compare the property.
/// </param>
/// <param name="operator">
/// The comparison operator.
/// </param>
/// <returns>A <see cref="Expression{TDelegate}"/> representing the comparison operation.</returns>
public static Expression <Func <T, bool> > CreateBinary <T>(string propertyNameOrPath, object value, ExpressionOperator @operator)
{
return(BuildBinaryExpression <T>(propertyNameOrPath, value, @operator));
}
public static string GetOperatorString(ExpressionOperator oper)
{
if (!operatorString.ContainsKey(oper))
return null;
return operatorString[oper];
}
public override TypedExpressionValue <bool> Compare(ExpressionValue expressionValue, ExpressionOperator op)
{
if (ValidCompare(expressionValue, op))
{
ExpressionBool expression;
switch (expressionValue.ExpressionType)
{
case ExpressionType.Bool:
expression = expressionValue as ExpressionBool;
break;
default:
throw new NotImplementedException();
}
AddToChain(expression.GetExpression(), op);
UsedIdentifiers = CombineElements(expressionValue);
return(this);
}
throw new InvalidOperationException(UserMessages.ExceptionNoComparison(ExpressionType, expressionValue.ExpressionType, op));
}
/// <summary>
/// parse an sql query text
/// </summary>
/// <param name="query">sql query text</param>
/// <param name="validator">sql query validator against a database</param>
/// <returns></returns>
public static DbQuery Parse(string query, IQueryValidation validator)
{
if (validator == null)
{
throw new ArgumentException("No query database validator provided");
}
int top = -1;
ColumnsSelect columnSelect = null;
var tableCollection = new List <Table>();
SqlJoin join = null;
ExpressionOperator where = null;
TokenItem PreviousToken = default(TokenItem);
TokenItem CurrentToken = default(TokenItem);
var peekedToken = default(TokenItem);
var columnCollection = new List <Column>();
Table joinTable = null;
var queue = new Queue <TokenItem>(ParseTokens(query));
//#if DEBUG
// Console.WriteLine("Query tokens:");
// Console.WriteLine($" {String.Join($"{Environment.NewLine} ", queue)}{Environment.NewLine}");
//#endif
bool EndOfStream = queue.Count == 0;
IEnumerable <Table> AllTables()
{
foreach (var t in tableCollection)
{
yield return(t);
}
if (joinTable != null)
{
yield return(joinTable);
}
}
bool GetToken()
{
if (EndOfStream || (EndOfStream = !queue.TryDequeue(out TokenItem tk)))
{
return(false);
}
//save previous
PreviousToken = CurrentToken;
//get current
CurrentToken = tk;
return(true);
}
bool PeekToken()
{
if (!EndOfStream && queue.TryPeek(out peekedToken))
{
return(true);
}
return(false);
}
bool GetTokenIf(TokenType token)
{
if (!EndOfStream && queue.TryPeek(out peekedToken) && peekedToken.Token == token)
{
CurrentToken = queue.Dequeue();
return(true);
}
return(false);
};
bool GetTokenIfContains(List <TokenType> tokens)
{
if (!EndOfStream && queue.TryPeek(out peekedToken) && tokens.Contains(peekedToken.Token))
{
CurrentToken = queue.Dequeue();
return(true);
}
return(false);
}
Column ReadColumnName(bool readAS = true)
{
Column selectColumn = null;
//read operand [(i).](column)
if (GetTokenIf(TokenType.Identifier))
{
var tableAlias = CurrentToken.Value;
String columnName = null;
String columnAlias = null;
if (GetTokenIf(TokenType.Dot))
{
if (!GetToken())
{
throw new ArgumentException($"column name expected");
}
columnName = CurrentToken.Value;
}
else
{
columnName = tableAlias;
tableAlias = null;
}
//alias
if (readAS && GetTokenIf(TokenType.AS))
{
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException($"Column alias name expected after AS: {CurrentToken.Value}");
}
columnAlias = CurrentToken.Value;
}
selectColumn = new Column(columnName, tableAlias, columnAlias);
}
return(selectColumn);
}
ExpressionOperand ReadOperand(DbColumnType casting)
{
if (!PeekToken())
{
return(null);
}
switch (peekedToken.Token)
{
case TokenType.String:
GetToken();
return(new StringOperand(CurrentToken.Value));
case TokenType.Number:
GetToken();
return(new NumberOperand(CurrentToken.Value, casting));
case TokenType.Identifier:
//get column name
GetToken();
var columnName = CurrentToken.Value;
var position = CurrentToken.Position;
String columnIdentifier = null;
if (GetTokenIf(TokenType.Dot))
{
//tablealias.colummname
if (!GetToken())
{
throw new ArgumentException($"column name expected");
}
columnIdentifier = columnName;
columnName = CurrentToken.Value;
}
Column col = null;
//try to find column in known tables
if (columnIdentifier != null)
{
//find in table by its alias
var aliasTable = AllTables().FirstOrDefault(t => t.Alias == columnIdentifier);
if (aliasTable == null)
{
throw new ArgumentException($"cannot find column: {columnName}");
}
col = new Column(columnName, aliasTable.Alias);
col.Meta = validator.ColumnMetadata(aliasTable.Name, col.Name);
}
else
{
//find the only first in all known tables
var tables = AllTables().Where(t => validator.TableHasColumn(t.Name, columnName)).ToList();
if (tables.Count != 1)
{
throw new ArgumentException($"column: {columnName} could not be found in database or cannot resolve multiple tables");
}
//tableName = tables[0].Name;
col = new Column(columnName, validator.ColumnMetadata(tables[0].Name, columnName));
}
return(new ColumnOperand(col, casting));
default:
return(null);
}
}
ExpressionOperator ReadExpression()
{
//https://stackoverflow.com/questions/3422673/evaluating-a-math-expression-given-in-string-form
var stack = new Stack <ExpressionItem>();
var operStack = new Stack <TokenType>();
ExpressionItem BuildTree()
{
//get higher precedence operator from operator stack
var oper = operStack.Pop();
//get left and right expressions
var right = stack.Pop();
var left = stack.Pop();
//create new expression
var expr = ExpressionOperator.Create(left, oper, right);
//push onto expression stack
stack.Push(expr);
return(expr);
}
var end = false;
while (!end)
{
if (!(end = !PeekToken()))
{
var currOper = peekedToken.Token;
switch (currOper)
{
case TokenType.String:
case TokenType.Number:
case TokenType.Identifier:
//if on top of stack there's a casting oper, apply it
DbColumnType casting = DbColumnType.None;
if (stack.Count > 0 && stack.Peek().ExpressionType == ExpressionItemType.Casting)
{
casting = (stack.Pop() as CastingExpression).Type;
}
//read operand and apply casting if any
stack.Push(ReadOperand(casting));
break;
case TokenType.OpenPar:
//consume the open parenthesis (
GetToken();
//try ahead if it's a casting operator
var currToken = CurrentToken.Token;
//try to get ahead a casting type
if (PeekToken() && (casting = peekedToken.Token.ToCast()).IsCasting())
{
//consume the casting type
GetToken();
if (!GetTokenIf(TokenType.ClosePar))
{
throw new ArgumentException("close parenthesis expected after casting type");
}
//store new casting expression
stack.Push(new CastingExpression(casting));
}
else
{
operStack.Push(currToken);
}
break;
case TokenType.ClosePar: // )
GetToken();
while (operStack.Count > 0 && operStack.Peek() != TokenType.OpenPar)
{
BuildTree();
}
//discard close parenthesis ) operator
operStack.Pop();
break;
default:
//operator
// AND OR == <> > >= < <=
if (currOper == TokenType.AND || currOper == TokenType.OR ||
currOper == TokenType.Equal || currOper == TokenType.NotEqual ||
currOper == TokenType.Greater || currOper == TokenType.GreaterOrEqual ||
currOper == TokenType.Less || currOper == TokenType.LessOrEqual)
{
GetToken();
var thisOper = CurrentToken.Token;
//build tree of all operator on stack with higher precedence than current
while (operStack.Count > 0 &&
Precedence(operStack.Peek()) < Precedence(thisOper))
{
BuildTree();
}
//
operStack.Push(thisOper);
}
else
{
throw new ArgumentException($"operator expected, and we got: {currOper}");
}
break;
}
}
}
//resolve left operator
while (operStack.Count > 0)
{
BuildTree();
}
if (stack.Count == 0)
{
return(null);
}
var item = stack.Pop();
if (item.ExpressionType != ExpressionItemType.Operator)
{
throw new ArgumentException("operator expected on expression");
}
return(item as ExpressionOperator);
}
int Precedence(TokenType token)
{
switch (token)
{
//case TokenType.NOT: // ~ BITWISE NOT
// return 1;
case TokenType.Astherisk: // * / %(modulus)
return(2);
case TokenType.Plus: // + - sign
case TokenType.Minus: // + addition, concatenation -substraction
return(3); // bitwise & AND, | OR |
case TokenType.Equal: //comparison operators
case TokenType.NotEqual:
case TokenType.Greater:
case TokenType.GreaterOrEqual:
case TokenType.Less:
case TokenType.LessOrEqual:
return(4);
case TokenType.NOT:
return(5);
case TokenType.AND:
return(6);
case TokenType.BETWEEN: //ALL, ANY, BETWEEN, IN, LIKE, OR, SOME
case TokenType.IN:
case TokenType.LIKE:
case TokenType.OR:
return(7);
case TokenType.Assign:
return(8);
case TokenType.OpenPar:
//highest
return(16);
default:
return(0);
}
}
#region SELECT
if (!GetTokenIf(TokenType.SELECT))
{
throw new ArgumentException("SELECT expected");
}
//see if it's a function
if (GetTokenIfContains(SelectFunctions))
{
var function = CurrentToken.Token;
if (!GetTokenIf(TokenType.OpenPar))
{
throw new ArgumentException($"expected ( after FUNCTION {CurrentToken.Token}");
}
// COUNT([(i).](column))
var functionColumn = ReadColumnName(readAS: false);
if (!GetTokenIf(TokenType.ClosePar))
{
throw new ArgumentException($"expected ) closing {CurrentToken.Token}");
}
//alias
String functionColumnAlias = null;
if (GetTokenIf(TokenType.AS))
{
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException($"");
}
functionColumnAlias = CurrentToken.Value;
}
columnSelect = new ColumnsSelect(function, functionColumn, functionColumnAlias);
}
else
{
//preceded by TOP if any
//TOP integer PERCENT
if (GetTokenIf(TokenType.TOP))
{
if (!GetTokenIf(TokenType.Number))
{
throw new ArgumentException($"Number expected after TOP");
}
//test for integer
if (!int.TryParse(CurrentToken.Value, out top) || top <= 0)
{
throw new ArgumentException($"TOP [positive integer greater than 0] expected: {CurrentToken.Value}");
}
//PERCENT
if (GetTokenIf(TokenType.PERCENT))
{
//save if for later
}
}
//read columns
//read column selector: comma separated or *
if (GetTokenIf(TokenType.Astherisk))
{
columnSelect = new ColumnsSelect(top);
}
else
{
//mut have at least one column identifier
if (PeekToken() && peekedToken.Token != TokenType.Identifier)
{
throw new ArgumentException("table column name(s) expected");
}
//read first
columnCollection.Add(ReadColumnName());
while (GetTokenIf(TokenType.Comma))
{
//next
columnCollection.Add(ReadColumnName());
}
columnSelect = new ColumnsSelect(top, columnCollection);
}
}
#endregion
#region FROM
if (!GetTokenIf(TokenType.FROM))
{
throw new ArgumentException("FROM expected");
}
do
{
//read identifier: table name
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException("table name identifier after FROM expected");
}
var tableName = CurrentToken.Value;
String tableAlias = null;
//var pos = CurrentToken.Position;
// [table name] AS [alias]
if (GetTokenIf(TokenType.AS))
{
//create it so WHERE can handle it
//tableIdentifier = new DbQueryTableIdentifier(table, CurrentToken.Value);
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException($"Table alias expected after AS");
}
tableAlias = CurrentToken.Value;
}
//tableIdentifier = new DbQueryTableIdentifier(table);
var table = new Table(tableName, tableAlias);
if (!validator.HasTable(table.Name))
{
throw new ArgumentException($"Invalid table name: {table.Name}");
}
tableCollection.Add(table);
}while (GetTokenIf(TokenType.Comma));
if (columnSelect.FullColumns)
{
//fill SELECT * with all columns in FROM if applies
foreach (var col in tableCollection
.SelectMany(
table => validator.ColumnsOf(table.Name),
(table, col) => new Column(col, validator.ColumnMetadata(table.Name, col))))
{
columnSelect.Add(col);
}
}
else
{
//check all SELECT columns
foreach (var col in columnSelect.Columns)
{
string tableName = null;
if (col.HasTableAlias)
{
//find it in table collection
var table = tableCollection.FirstOrDefault(t => t.HasAlias && col.TableAlias == t.Alias);
if (table == null)
{
throw new ArgumentException($"column alias undefined {col}");
}
tableName = table.Name;
if (!validator.TableHasColumn(tableName, col.Name))
{
throw new ArgumentException($"column: {col.Name} could not be found in table {tableName}");
}
}
else
{
//brute force search
var tables = tableCollection.Where(t => validator.TableHasColumn(t.Name, col.Name)).ToList();
if (tables.Count != 1)
{
throw new ArgumentException($"column: {col.Name} could not be found in database or cannot resolve multiple tables");
}
tableName = tables[0].Name;
}
//link column to table, and find its index
col.Meta = validator.ColumnMetadata(tableName, col.Name);
}
}
#endregion
#region JOIN
if (GetTokenIfContains(JoinStarts))
{
//FROM table must has identifier, should be only one here
TokenType JoinCommand = CurrentToken.Token;
ComparisonOperator JoinExpression = null;
if (CurrentToken.Token == TokenType.LEFT || CurrentToken.Token == TokenType.RIGHT ||
CurrentToken.Token == TokenType.FULL)
{
//LEFT OUTER JOIN
//RIGHT OUTER JOIN
//FULL OUTER JOIN
if (!GetTokenIf(TokenType.OUTER))
{
throw new ArgumentException($"OUTER expected after {CurrentToken.Token}");
}
}
else if (!(CurrentToken.Token == TokenType.INNER || CurrentToken.Token == TokenType.CROSS))
{
//INNER JOIN
//CROSS JOIN
throw new ArgumentException($"invalid JOIN keyword {CurrentToken.Token}");
}
if (!GetTokenIf(TokenType.JOIN))
{
throw new ArgumentException($"JOIN expected after {CurrentToken.Token}");
}
//read table name
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException("table name identifier after FROM expected");
}
//check -table name
var tableName = CurrentToken.Value;
String tableAlias = null;
// + identifier
if (GetTokenIf(TokenType.AS))
{
if (!GetTokenIf(TokenType.Identifier))
{
throw new ArgumentException($"Table alias expected after AS");
}
tableAlias = CurrentToken.Value;
}
joinTable = new Table(tableName, tableAlias);
if (!validator.HasTable(joinTable.Name))
{
throw new ArgumentException($"Invalid table name: {joinTable.Name}");
}
//read ON
if (!GetTokenIf(TokenType.ON))
{
throw new ArgumentException($"ON expected in JOIN query");
}
//read expression
//left & right operand must be from different tables
//read left
var left = ReadOperand(DbColumnType.None);
//read operator
if (!GetToken() || !CurrentToken.Token.IsOperator())
{
throw new ArgumentException("operator of JOIN expression expected");
}
var oper = CurrentToken;
//read right
var right = ReadOperand(DbColumnType.None);
//operands must be of type column with different table identifiers
if (!left.IsColumn ||
!right.IsColumn ||
((ColumnOperand)left).Column.TableAlias == ((ColumnOperand)right).Column.TableAlias)
{
throw new ArgumentException("JOIN query expression table identifiers cannot be the same");
}
JoinExpression = new ComparisonOperator(
left,
oper.Token,
right
);
join = new SqlJoin(JoinCommand, joinTable, JoinExpression);
//validate JOIN column tables
}
#endregion
#region WHERE if any
if (GetTokenIf(TokenType.WHERE))
{
if ((where = ReadExpression()) == null)
{
throw new ArgumentException("WHERE expression(s) expected");
}
}
#endregion
if (GetToken() && CurrentToken.Token != TokenType.SemiColon)
{
throw new ArgumentException($"Unexpected: {CurrentToken.Value} @ {CurrentToken.Position}");
}
return(new DbQuery(columnSelect, tableCollection, join, new ColumnsWhere(where)));
}
protected ODataExpression(ODataExpression left, ODataExpression right, ExpressionOperator expressionOperator)
{
_left = left;
_right = right;
_operator = expressionOperator;
}
/// <summary>
/// Combines two expressions
/// </summary>
/// <param name="item1">Left hand side</param>
/// <param name="item2">Right hand side</param>
/// <param name="op">Operator</param>
/// <returns>Resulting delegate</returns>
protected override Func <int> CombineExpressions(Func <int> item1, Func <int> item2, ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.Plus:
return(() => item1() + item2());
case ExpressionOperator.Minus:
return(() => item1() - item2());
case ExpressionOperator.Multiply:
return(() => item1() * item2());
case ExpressionOperator.Divide:
return(() => item1() / item2());
}
throw new NotImplementedException();
}
private FilterExpression(FilterExpression left, FilterExpression right, ExpressionOperator expressionOperator)
{
_left = left;
_right = right;
_operator = expressionOperator;
}
/// <summary>
/// Compares expression with double expression
/// </summary>
/// <param name="item">double expression</param>
/// <param name="op">Compare operator</param>
/// <returns>Boolean expression</returns>
private TypedExpressionValue <bool> CompareValue(TypedExpressionValue <double> item, ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.GreaterThan:
return(new ExpressionBool(CombineWidgets(item), () => { return Result > item.Result; }));
case ExpressionOperator.GreaterEquals:
return(new ExpressionBool(CombineWidgets(item), () => { return Result >= item.Result; }));
case ExpressionOperator.LessThan:
return(new ExpressionBool(CombineWidgets(item), () => { return Result < item.Result; }));
case ExpressionOperator.LessEquals:
return(new ExpressionBool(CombineWidgets(item), () => { return Result <= item.Result; }));
case ExpressionOperator.Equals:
return(new ExpressionBool(CombineWidgets(item), () => { return Result == item.Result; }));
}
throw new InvalidOperationException(UserMessages.ExceptionNoComparison(Type, item.Type, op));
}
/// <summary>
///
/// </summary>
/// <param name="fieldName"></param>
/// <param name="expressionOperator"></param>
/// <param name="fieldValue"></param>
public FilterExpression(string fieldName, ExpressionOperator expressionOperator, string fieldValue)
{
FieldName = fieldName;
ExpressionOperator = expressionOperator;
FieldValue = fieldValue;
}
/// <returns>
/// A (textual representation of the) C# operator for <code>op</code>
/// </returns>
public static string ToString(ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.Addition:
return("+");
case ExpressionOperator.And:
return("&");
case ExpressionOperator.Constant:
return("<CONST>");
case ExpressionOperator.ConvertToInt32:
return("(Int32)");
case ExpressionOperator.ConvertToUInt16:
return("(UInt16)");
case ExpressionOperator.ConvertToUInt32:
return("(UInt32)");
case ExpressionOperator.ConvertToUInt8:
return("(UInt8)");
case ExpressionOperator.ConvertToFloat32:
return("(Single)");
case ExpressionOperator.ConvertToFloat64:
return("(Double)");
case ExpressionOperator.Division:
return("/");
case ExpressionOperator.Equal:
return("==");
case ExpressionOperator.Equal_Obj:
return("=Equals=");
case ExpressionOperator.GreaterEqualThan:
return(">=");
case ExpressionOperator.GreaterEqualThan_Un:
return(">=_un");
case ExpressionOperator.GreaterThan:
return(">");
case ExpressionOperator.GreaterThan_Un:
return(">_un");
case ExpressionOperator.LessEqualThan:
return("<=");
case ExpressionOperator.LessEqualThan_Un:
return("<=_un");
case ExpressionOperator.LessThan:
return("<");
case ExpressionOperator.LessThan_Un:
return("<_un");
case ExpressionOperator.LogicalAnd:
return("&&");
case ExpressionOperator.LogicalNot:
return("!");
case ExpressionOperator.LogicalOr:
return("||");
case ExpressionOperator.Modulus:
return("%");
case ExpressionOperator.Multiplication:
return("*");
case ExpressionOperator.Not:
return("!");
case ExpressionOperator.NotEqual:
return("!=");
case ExpressionOperator.Or:
return("|");
case ExpressionOperator.Xor:
return("^");
case ExpressionOperator.ShiftLeft:
return("<<");
case ExpressionOperator.ShiftRight:
return(">>");
case ExpressionOperator.SizeOf:
return("sizeof");
case ExpressionOperator.Subtraction:
return("-");
case ExpressionOperator.UnaryMinus:
return("-");
case ExpressionOperator.Unknown:
return("<???>");
case ExpressionOperator.Variable:
return("<VAR>");
case ExpressionOperator.WritableBytes:
return("<WritableBytes>");
default:
return("<????>");
}
}
public abstract TInterval ApplyConversion(ExpressionOperator conv, TInterval intv);
protected DynamicODataExpression(ODataExpression left, ODataExpression right, ExpressionOperator expressionOperator)
: base(left, right, expressionOperator)
{
}
private int processOperator(string expression, int originalOperatorIndex, Operator originalOperator, Stack operatorStack, Stack operandStack, bool haveOperand, Operator unaryOperator)
{
int operatorIndex = originalOperatorIndex;
Operator @operator = originalOperator;
if (haveOperand && @operator is OpenParenthesesOperator)
{
NextOperator nextOperator = processFunction(expression, operatorIndex, operandStack);
@operator = nextOperator.Operator;
operatorIndex = nextOperator.Index + @operator.Length;
nextOperator = getNextOperator(expression, operatorIndex, null);
if (nextOperator != null)
{
@operator = nextOperator.Operator;
operatorIndex = nextOperator.Index;
}
else
{
return(operatorIndex);
}
}
if (@operator is OpenParenthesesOperator)
{
ExpressionOperator expressionOperator = new ExpressionOperator(@operator, unaryOperator);
operatorStack.Push(expressionOperator);
}
else if (@operator is ClosedParenthesesOperator)
{
ExpressionOperator stackOperator = null;
if (operatorStack.Count > 0)
{
stackOperator = (ExpressionOperator)operatorStack.Peek();
}
// Process until we reach an open parentheses.
while (stackOperator != null && !(stackOperator.Operator is OpenParenthesesOperator))
{
processTree(operandStack, operatorStack);
if (operatorStack.Count > 0)
{
stackOperator = (ExpressionOperator)operatorStack.Peek();
}
else
{
stackOperator = null;
}
}
if (operatorStack.Count == 0)
{
throw new EvaluationException("Expression is invalid.");
}
ExpressionOperator expressionOperator = (ExpressionOperator)operatorStack.Pop();
if (!(expressionOperator.Operator is OpenParenthesesOperator))
{
throw new EvaluationException("Expression is invalid.");
}
// Process the unary operator if we have one.
if (expressionOperator.UnaryOperator != null)
{
object operand = operandStack.Pop();
ExpressionTree tree = new ExpressionTree(this, operand, null, null, expressionOperator.UnaryOperator);
operandStack.Push(tree);
}
}
else
{
// Process non-param operator.
if (operatorStack.Count > 0)
{
ExpressionOperator stackOperator = (ExpressionOperator)operatorStack.Peek();
while (stackOperator != null && stackOperator.Operator.Precedence >= @operator.Precedence)
{
processTree(operandStack, operatorStack);
if (operatorStack.Count > 0)
{
stackOperator = (ExpressionOperator)operatorStack.Peek();
}
else
{
stackOperator = null;
}
}
}
ExpressionOperator expressionOperator = new ExpressionOperator(@operator, unaryOperator);
operatorStack.Push(expressionOperator);
}
int rtnCtr = operatorIndex + @operator.Length;
return(rtnCtr);
}
public static void Rule(Expression result, Expression expression, ExpressionOperator op, Term term)
{
result.Value = op.Function(expression.Value, term.Value);
}
/// <summary>
/// Compares with expression
/// </summary>
/// <param name="expressionValue">Expression to compare with</param>
/// <param name="op">Operator</param>
/// <returns>Boolean expression</returns>
public override TypedExpressionValue <bool> Compare(ExpressionValue expressionValue, ExpressionOperator op)
{
if (ValidCompare(expressionValue, op))
{
if (expressionValue.Type == typeof(bool))
{
AddToChain((expressionValue as ExpressionBool).GetExpression(), op);
UsedWidgetIDs = CombineWidgets(expressionValue);
return(this);
}
}
throw new InvalidOperationException(UserMessages.ExceptionNoComparison(Type, expressionValue.Type, op));
}
private int GetPrecedence(ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.NOT:
case ExpressionOperator.NEG:
return 1;
case ExpressionOperator.MOD:
case ExpressionOperator.MUL:
case ExpressionOperator.DIV:
return 2;
case ExpressionOperator.ADD:
case ExpressionOperator.SUB:
return 3;
case ExpressionOperator.GT:
case ExpressionOperator.GE:
case ExpressionOperator.LT:
case ExpressionOperator.LE:
return 4;
case ExpressionOperator.EQ:
case ExpressionOperator.NE:
return 5;
case ExpressionOperator.AND:
return 6;
case ExpressionOperator.OR:
return 7;
default:
return 0;
}
}
/// <summary>
/// Combines two boolean expressions
/// </summary>
/// <param name="item1">Left hand side</param>
/// <param name="item2">Right hand side</param>
/// <param name="op">Operator</param>
/// <returns>Resulting delegate</returns>
protected override Func <bool> CombineExpressions(Func <bool> item1, Func <bool> item2, ExpressionOperator op)
{
switch (op)
{
case ExpressionOperator.And:
return(() => item1() && item2());
case ExpressionOperator.Or:
return(() => item1() || item2());
case ExpressionOperator.Equals:
return(() => item1() == item2());
}
throw new InvalidOperationException(UserMessages.ExceptionNoCombination(Type, Type, op));
}
protected internal ODataExpression(ODataExpression left, ODataExpression right, ExpressionOperator expressionOperator)
{
_left = left;
_right = right;
_operator = expressionOperator;
}
Polynomial <TVar, TExpr> SwapOperands(ExpressionOperator newOp)
{
return(new Polynomial <TVar, TExpr> (newOp, right, left));
}
public ExpressionData( string left, ExpressionOperator ope, object right )
: this()
{
LeftOperand = left;
Operator = ope;
RightOperand = right;
}
protected DynamicFilterExpression(FilterExpression left, FilterExpression right, ExpressionOperator expressionOperator)
: base(left, right, expressionOperator)
{
}
