public void Can_Where_using_constant_filter()
{
object left = null;
var right = new PartialSqlString("null");
System.Linq.Expressions.Expression <Func <TestType, bool> > filter = x => left == right;
var q = Db.From <TestType>().Where(filter);//todo: here Where: null is NULL. May be need to change to 1=1 ?
var target = Db.Select(q);
Assert.That(target.Count, Is.EqualTo(4));
}
protected override string SubstringStatement(PartialSqlString columnName, int startIndex, int length)
{
if (length >= 0)
{
return(string.Format("substring({0} FROM {1} FOR {2})", columnName, CreateParam(startIndex), CreateParam(length)));
}
else
{
return(string.Format("substring({0} FROM {1})", columnName, CreateParam(startIndex)));
}
}
protected override string SubstringStatement(PartialSqlString columnName, int startIndex, int length)
{
// Substring function doesn't work with parameters
if (length >= 0)
{
return(string.Format("substring({0} FROM {1} FOR {2})", columnName, startIndex, length));
}
else
{
return(string.Format("substring({0} FROM {1})", columnName, startIndex));
}
}
/// <summary>Visit binary.</summary>
/// <param name="b">The BinaryExpression to process.</param>
/// <returns>An object.</returns>
protected override object VisitBinary(BinaryExpression b)
{
object left, right;
var operand = BindOperant(b.NodeType); //sep= " " ??
if (operand == "AND" || operand == "OR")
{
var m = b.Left as MemberExpression;
if (m != null && m.Expression != null &&
m.Expression.NodeType == ExpressionType.Parameter)
{
left = new PartialSqlString(string.Format("{0}={1}", VisitMemberAccess(m), GetQuotedTrueValue()));
}
else
{
left = Visit(b.Left);
}
m = b.Right as MemberExpression;
if (m != null && m.Expression != null &&
m.Expression.NodeType == ExpressionType.Parameter)
{
right = new PartialSqlString(string.Format("{0}={1}", VisitMemberAccess(m), GetQuotedTrueValue()));
}
else
{
right = Visit(b.Right);
}
if (left as PartialSqlString == null && right as PartialSqlString == null)
{
var result = Expression.Lambda(b).Compile().DynamicInvoke();
return(new PartialSqlString(OrmLiteConfig.DialectProvider.GetQuotedValue(result, result.GetType())));
}
if (left as PartialSqlString == null)
{
left = ((bool)left) ? GetTrueExpression() : GetFalseExpression();
}
if (right as PartialSqlString == null)
{
right = ((bool)right) ? GetTrueExpression() : GetFalseExpression();
}
}
else
{
left = Visit(b.Left);
right = Visit(b.Right);
if (left as EnumMemberAccess != null)
{
var enumType = ((EnumMemberAccess)left).EnumType;
//enum value was returned by Visit(b.Right)
long numvericVal;
if (Int64.TryParse(right.ToString(), out numvericVal))
{
right = OrmLiteConfig.DialectProvider.GetQuotedValue(Enum.ToObject(enumType, numvericVal).ToString(),
typeof(string));
}
else
{
right = OrmLiteConfig.DialectProvider.GetQuotedValue(right, right.GetType());
}
}
else if (right as EnumMemberAccess != null)
{
var enumType = ((EnumMemberAccess)right).EnumType;
//enum value was returned by Visit(b.Left)
long numvericVal;
if (Int64.TryParse(left.ToString(), out numvericVal))
{
left = OrmLiteConfig.DialectProvider.GetQuotedValue(Enum.ToObject(enumType, numvericVal).ToString(),
typeof(string));
}
else
{
left = OrmLiteConfig.DialectProvider.GetQuotedValue(left, left.GetType());
}
}
else if (left as PartialSqlString == null && right as PartialSqlString == null)
{
var result = Expression.Lambda(b).Compile().DynamicInvoke();
return(result);
}
else if (left as PartialSqlString == null)
{
left = OrmLiteConfig.DialectProvider.GetQuotedValue(left, left != null ? left.GetType() : null);
}
else if (right as PartialSqlString == null)
{
right = OrmLiteConfig.DialectProvider.GetQuotedValue(right, right != null ? right.GetType() : null);
}
}
if (operand == "=" && right.ToString() == "null")
{
operand = "is";
}
else if (operand == "<>" && right.ToString() == "null")
{
operand = "is not";
}
else if (operand == "=" || operand == "<>")
{
if (IsTrueExpression(right))
{
right = GetQuotedTrueValue();
}
else if (IsFalseExpression(right))
{
right = GetQuotedFalseValue();
}
if (IsTrueExpression(left))
{
left = GetQuotedTrueValue();
}
else if (IsFalseExpression(left))
{
left = GetQuotedFalseValue();
}
}
switch (operand)
{
case "MOD":
case "COALESCE":
return(new PartialSqlString(string.Format("{0}({1},{2})", operand, left, right)));
default:
return(new PartialSqlString("(" + left + Sep + operand + Sep + right + ")"));
}
}
protected override object VisitBinary(BinaryExpression b)
{
object left, right;
var operand = BindOperant(b.NodeType); //sep= " " ??
if (operand == "AND" || operand == "OR")
{
var m = b.Left as MemberExpression;
if (m != null && m.Expression != null &&
m.Expression.NodeType == ExpressionType.Parameter)
{
left = new PartialSqlString(string.Format("{0}={1}", VisitMemberAccess(m), GetQuotedTrueValue()));
}
else
{
left = Visit(b.Left);
}
m = b.Right as MemberExpression;
if (m != null && m.Expression != null &&
m.Expression.NodeType == ExpressionType.Parameter)
{
right = new PartialSqlString(string.Format("{0}={1}", VisitMemberAccess(m), GetQuotedTrueValue()));
}
else
{
right = Visit(b.Right);
}
if (left as PartialSqlString == null && right as PartialSqlString == null)
{
var result = Expression.Lambda(b).Compile().DynamicInvoke();
return(new PartialSqlString(base.DialectProvider.GetQuotedValue(result, result.GetType())));
}
if (left as PartialSqlString == null)
{
left = ((bool)left) ? GetTrueExpression() : GetFalseExpression();
}
if (right as PartialSqlString == null)
{
right = ((bool)right) ? GetTrueExpression() : GetFalseExpression();
}
}
else
{
left = Visit(b.Left);
right = Visit(b.Right);
var leftEnum = left as EnumMemberAccess;
var rightEnum = right as EnumMemberAccess;
var rightNeedsCoercing = leftEnum != null && rightEnum == null;
var leftNeedsCoercing = rightEnum != null && leftEnum == null;
if (rightNeedsCoercing)
{
var rightPartialSql = right as PartialSqlString;
if (rightPartialSql == null)
{
right = GetValue(right, leftEnum.EnumType);
}
}
else if (leftNeedsCoercing)
{
var leftPartialSql = left as PartialSqlString;
if (leftPartialSql == null)
{
left = DialectProvider.GetQuotedValue(left, rightEnum.EnumType);
}
}
else if (left as PartialSqlString == null && right as PartialSqlString == null)
{
var result = Expression.Lambda(b).Compile().DynamicInvoke();
return(result);
}
else if (left as PartialSqlString == null)
{
left = DialectProvider.GetQuotedValue(left, left != null ? left.GetType() : null);
}
else if (right as PartialSqlString == null)
{
right = GetValue(right, right != null ? right.GetType() : null);
}
}
if (operand == "=" && right.ToString().EqualsIgnoreCase("null"))
{
operand = "is";
}
else if (operand == "<>" && right.ToString().EqualsIgnoreCase("null"))
{
operand = "is not";
}
else if (operand == "=" || operand == "<>")
{
if (IsTrueExpression(right))
{
right = GetQuotedTrueValue();
}
else if (IsFalseExpression(right))
{
right = GetQuotedFalseValue();
}
if (IsTrueExpression(left))
{
left = GetQuotedTrueValue();
}
else if (IsFalseExpression(left))
{
left = GetQuotedFalseValue();
}
}
switch (operand)
{
case "MOD":
case "COALESCE":
return(new PartialSqlString(string.Format("{0}({1},{2})", operand, left, right)));
default:
return(new PartialSqlString("(" + left + Sep + operand + Sep + right + ")"));
}
}
protected override string TrimStatement(PartialSqlString expression)
{
return(string.Format("ltrim(rtrim({0}))", expression));
}
public void Can_Where_using_constant_filter()
{
object left = null;
var right = new PartialSqlString("null");
System.Linq.Expressions.Expression<Func<TestType, bool>> filter = x => left == right;
var q = Db.From<TestType>().Where(filter);//todo: here Where: null is NULL. May be need to change to 1=1 ?
var target = Db.Select(q);
Assert.That(target.Count, Is.EqualTo(4));
}
protected virtual object VisitBinary(BinaryExpression b)
{
object originalLeft = null, originalRight = null, left, right;
var operand = BindOperant(b.NodeType); //sep= " " ??
if (operand == "AND" || operand == "OR")
{
if (IsBooleanComparison(b.Left))
{
left = VisitMemberAccess((MemberExpression)b.Left);
if (left is PartialSqlString)
{
left = new PartialSqlString($"{left}={GetQuotedTrueValue()}");
}
}
else
{
left = Visit(b.Left);
}
if (IsBooleanComparison(b.Right))
{
right = VisitMemberAccess((MemberExpression)b.Right);
if (right is PartialSqlString)
{
right = new PartialSqlString($"{right}={GetQuotedTrueValue()}");
}
}
else
{
right = Visit(b.Right);
}
if (!(left is PartialSqlString) && !(right is PartialSqlString))
{
var result = PreEvaluateBinary(b, left, right);
return(result);
}
if (!(left is PartialSqlString))
{
left = ((bool)left) ? GetTrueExpression() : GetFalseExpression();
}
if (!(right is PartialSqlString))
{
right = ((bool)right) ? GetTrueExpression() : GetFalseExpression();
}
}
else if ((operand == "=" || operand == "<>") && b.Left is MethodCallExpression && ((MethodCallExpression)b.Left).Method.Name == "CompareString")
{
//Handle VB.NET converting (x => x.Name == "Foo") into (x => CompareString(x.Name, "Foo", False)
var methodExpr = (MethodCallExpression)b.Left;
var args = this.VisitExpressionList(methodExpr.Arguments);
right = GetValue(args[1], typeof(string));
ConvertToPlaceholderAndParameter(ref right);
return(new PartialSqlString($"({args[0]} {operand} {right})"));
}
else
{
originalLeft = left = Visit(b.Left);
originalRight = right = Visit(b.Right);
// Handle "expr = true/false", including with the constant on the left
if (operand == "=" || operand == "<>")
{
if (left is bool)
{
Swap(ref left, ref right); // Should be safe to swap for equality/inequality checks
}
if (right is bool && !IsFieldName(left)) // Don't change anything when "expr" is a column name - then we really want "ColName = 1"
{
if (operand == "=")
{
return((bool)right ? left : GetNotValue(left)); // "expr == true" becomes "expr", "expr == false" becomes "not (expr)"
}
if (operand == "<>")
{
return((bool)right ? GetNotValue(left) : left); // "expr != true" becomes "not (expr)", "expr != false" becomes "expr"
}
}
}
var leftEnum = left as EnumMemberAccess;
var rightEnum = right as EnumMemberAccess;
var rightNeedsCoercing = leftEnum != null && rightEnum == null;
var leftNeedsCoercing = rightEnum != null && leftEnum == null;
if (rightNeedsCoercing)
{
var rightPartialSql = right as PartialSqlString;
if (rightPartialSql == null)
{
right = GetValue(right, leftEnum.EnumType);
}
}
else if (leftNeedsCoercing)
{
var leftPartialSql = left as PartialSqlString;
if (leftPartialSql == null)
{
left = GetQuotedValue(left, rightEnum.EnumType);
}
}
else if (!(left is PartialSqlString) && !(right is PartialSqlString))
{
var evaluatedValue = PreEvaluateBinary(b, left, right);
var result = VisitConstant(Expression.Constant(evaluatedValue));
return(result);
}
else if (!(left is PartialSqlString))
{
left = GetQuotedValue(left, left?.GetType());
}
else if (!(right is PartialSqlString))
{
right = GetValue(right, right?.GetType());
}
}
if (left.ToString().Equals("null", StringComparison.OrdinalIgnoreCase))
{
Swap(ref left, ref right); // "null is x" will not work, so swap the operands
}
var separator = " "; //sep;
if (right.ToString().Equals("null", StringComparison.OrdinalIgnoreCase))
{
if (operand == "=")
{
operand = "is";
}
else if (operand == "<>")
{
operand = "is not";
}
separator = " ";
}
if (operand == "+" && b.Left.Type == typeof(string) && b.Right.Type == typeof(string))
{
return(BuildConcatExpression(new List <object> {
left, right
}));
}
VisitFilter(operand, originalLeft, originalRight, ref left, ref right);
switch (operand)
{
case "MOD":
case "COALESCE":
return(new PartialSqlString($"{operand}({left},{right})"));
default:
return(new PartialSqlString("(" + left + separator + operand + separator + right + ")"));
}
}
