public static UnaryRestDbExpression Avg(RestDbExpression expression)
{
if (!expression.ReturnColumnType.IsNumeric())
{
throw new ArgumentException("Expression return type must be numeric");
}
return(new UnaryRestDbExpression(RestDbExpressionType.Avg, expression.ReturnColumnType, expression));
}
public static RestDbExpression Div(RestDbExpression left, RestDbExpression right)
{
if (!left.ReturnColumnType.IsNumeric() || !right.ReturnColumnType.IsNumeric())
{
throw new ArgumentException("Argument must be of numeric type");
}
return(new BinaryRestDbExpression(RestDbExpressionType.Div, ColumnType.Decimal, left, right));
}
public static BinaryRestDbExpression NotIn(RestDbExpression left, RestDbExpression right)
{
if (right.ReturnColumnType != ColumnType.Array && left.ReturnColumnType != right.ReturnColumnType)
{
throw new ArgumentException($"Expression type [{right.ReturnColumnType}] does not match [{left.ReturnColumnType}]", nameof(right));
}
return(new BinaryRestDbExpression(RestDbExpressionType.NotIn, ColumnType.Boolean, left, right));
}
public static UnaryRestDbExpression Not(RestDbExpression expression)
{
if (expression.ReturnColumnType != ColumnType.Boolean)
{
throw new ArgumentException("NOT parameter expression must be of type boolean");
}
return(new UnaryRestDbExpression(RestDbExpressionType.Not, ColumnType.Boolean, expression));
}
public static BinaryRestDbExpression LessThanOrEqual(RestDbExpression left, RestDbExpression right)
{
if (left.ReturnColumnType != right.ReturnColumnType)
{
throw new ArgumentException($"Expression type [{right.ReturnColumnType}] does not match [{left.ReturnColumnType}]", nameof(right));
}
return(new BinaryRestDbExpression(RestDbExpressionType.LessThanOrEqual, ColumnType.Boolean, left, right));
}
public static RestDbExpression ToRestDbExpression(this ExpressionNode expressionNode, Dictionary <string, ColumnDefinition> columns)
{
// variadic expressions
if (expressionNode.Children.Count >= 2)
{
switch (expressionNode.Name.ToLower())
{
case "add":
return(RestDbExpression.Add(expressionNode.Children.Select(n => n.ToRestDbExpression(columns))));
case "mul":
return(RestDbExpression.Mul(expressionNode.Children.Select(n => n.ToRestDbExpression(columns))));
case "and":
return(RestDbExpression.And(expressionNode.Children.Select(n => n.ToRestDbExpression(columns))));
case "or":
return(RestDbExpression.Or(expressionNode.Children.Select(n => n.ToRestDbExpression(columns))));
}
}
// binary expressions
if (expressionNode.Children.Count == 2)
{
switch (expressionNode.Name.ToLower())
{
case "eq":
return(RestDbExpression.Equal(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "ne":
return(RestDbExpression.NotEqual(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "gt":
return(RestDbExpression.GreaterThan(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "gte":
return(RestDbExpression.GreaterThanOrEqual(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "lt":
return(RestDbExpression.LessThan(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "lte":
return(RestDbExpression.LessThanOrEqual(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "in":
return(RestDbExpression.In(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
case "nin":
return(RestDbExpression.NotIn(expressionNode.Children[0].ToRestDbExpression(columns), expressionNode.Children[1].ToRestDbExpression(columns)));
}
}
// unary expressions
if (expressionNode.Children.Count == 1)
{
switch (expressionNode.Name.ToLower())
{
case "not":
return(RestDbExpression.Not(expressionNode.Children[0].ToRestDbExpression(columns)));
default:
if (!expressionNode.Children[0].Children.Any() &&
Enum.TryParse <ColumnType>(expressionNode.Name, true, out var columnType))
{
var value = expressionNode.Children[0].Name.ConvertTo(columnType);
return(RestDbExpression.Constant(value));
}
break;
}
}
// array
if (expressionNode.Children.Count > 0 && expressionNode.Name == "")
{
return(RestDbExpression.Array(expressionNode.Children.Select(n => n.ToRestDbExpression(columns))));
}
// columns or values
if (expressionNode.Children.Count == 0)
{
if (expressionNode.Name.StartsWith("@"))
{
var columnName = expressionNode.Name.Substring(1);
var column = columns.GetValueOrDefault(columnName);
if (column == null)
{
throw new ArgumentException($"Column [{columnName}] does not exists", nameof(expressionNode));
}
return(RestDbExpression.Column(column.ColumnType, columnName));
}
return(RestDbExpression.Constant(expressionNode.Name.ToColumnValue()));
}
throw new ArgumentException($"Operation {expressionNode.Name}({string.Join(",", expressionNode.Children.Select(c => c.Name))}) not supported", nameof(expressionNode));
}
public static string ToSql(this RestDbExpression expression, Dictionary <string, object> parameters)
{
switch (expression)
{
case VariadicRestDbExpression {
NodeType: RestDbExpressionType.Add
} expr:
return("(" + string.Join(" + ", expr.Expressions.Select(e => e.ToSql(parameters))) + ")");
case VariadicRestDbExpression {
NodeType: RestDbExpressionType.Mul
} expr:
return("(" + string.Join(" * ", expr.Expressions.Select(e => e.ToSql(parameters))) + ")");
case VariadicRestDbExpression {
NodeType: RestDbExpressionType.And
} expr:
return("(" + string.Join(" AND ", expr.Expressions.Select(e => e.ToSql(parameters))) + ")");
case VariadicRestDbExpression {
NodeType: RestDbExpressionType.Or
} expr:
return("(" + string.Join(" OR ", expr.Expressions.Select(e => e.ToSql(parameters))) + ")");
case UnaryRestDbExpression {
NodeType: RestDbExpressionType.Not
} expr:
return($"NOT({expr.Expression.ToSql(parameters)})");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.Equal
} expr:
return($"{expr.Left.ToSql(parameters)}={expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.NotEqual
} expr:
return($"{expr.Left.ToSql(parameters)}!={expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.GreaterThan
} expr:
return($"{expr.Left.ToSql(parameters)}>{expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.GreaterThanOrEqual
} expr:
return($"{expr.Left.ToSql(parameters)}>={expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.LessThan
} expr:
return($"{expr.Left.ToSql(parameters)}<{expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.LessThanOrEqual
} expr:
return($"{expr.Left.ToSql(parameters)}<={expr.Right.ToSql(parameters)}");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.In
} expr:
return($"{expr.Left.ToSql(parameters)} IN ({expr.Right.ToSql(parameters)})");
case BinaryRestDbExpression {
NodeType: RestDbExpressionType.NotIn
} expr:
return($"{expr.Left.ToSql(parameters)} NOT IN ({expr.Right.ToSql(parameters)})");
case ArrayRestDbExpression {
NodeType: RestDbExpressionType.Array
} expr:
return(string.Join(",", expr.Expressions.Select(e => e.ToSql(parameters))));
case ColumnRestDbExpression {
NodeType: RestDbExpressionType.Column
} expr:
return(expr.ColumnName);
case ConstantRestDbExpression {
NodeType: RestDbExpressionType.Constant
} expr:
{
var parameterName = $"p{parameters.Count}";
parameters[parameterName] = expr.Value;
return($"@{parameterName}");
}
}
throw new NotSupportedException($"Unsupported expression {expression.NodeType}");
}
public BinaryRestDbExpression(RestDbExpressionType nodeType, ColumnType returnColumnType,
RestDbExpression left, RestDbExpression right) : base(nodeType, returnColumnType)
{
Left = left;
Right = right;
}
public UnaryRestDbExpression(RestDbExpressionType restDbExpressionType, ColumnType returnColumnType, RestDbExpression expression) : base(restDbExpressionType, returnColumnType)
{
Expression = expression;
}