// ?a == ?b -> [(a == b) && (a != null && b != null)] || (a == null && b == null))
//
// a | b | F1 = a == b | F2 = (a != null && b != null) | F3 = F1 && F2 |
// | | | | |
// 0 | 0 | 1 | 1 | 1 |
// 0 | 1 | 0 | 1 | 0 |
// 0 | N | N | 0 | 0 |
// 1 | 0 | 0 | 1 | 0 |
// 1 | 1 | 1 | 1 | 1 |
// 1 | N | N | 0 | 0 |
// N | 0 | N | 0 | 0 |
// N | 1 | N | 0 | 0 |
// N | N | N | 0 | 0 |
//
// a | b | F4 = (a == null && b == null) | Final = F3 OR F4 |
// | | | |
// 0 | 0 | 0 | 1 OR 0 = 1 |
// 0 | 1 | 0 | 0 OR 0 = 0 |
// 0 | N | 0 | 0 OR 0 = 0 |
// 1 | 0 | 0 | 0 OR 0 = 0 |
// 1 | 1 | 0 | 1 OR 0 = 1 |
// 1 | N | 0 | 0 OR 0 = 0 |
// N | 0 | 0 | 0 OR 0 = 0 |
// N | 1 | 0 | 0 OR 0 = 0 |
// N | N | 1 | 0 OR 1 = 1 |
private SqlBinaryExpression ExpandNullableEqualNullable(
SqlExpression left, SqlExpression right, SqlExpression leftIsNull, SqlExpression rightIsNull)
=> _sqlExpressionFactory.OrElse(
_sqlExpressionFactory.AndAlso(
_sqlExpressionFactory.Equal(left, right),
_sqlExpressionFactory.AndAlso(
_sqlExpressionFactory.Not(leftIsNull),
_sqlExpressionFactory.Not(rightIsNull))),
_sqlExpressionFactory.AndAlso(
leftIsNull,
rightIsNull));
private SqlExpression TranslateStartsEndsWith(SqlExpression instance, SqlExpression pattern, bool startsWith)
{
var stringTypeMapping = ExpressionExtensions.InferTypeMapping(instance, pattern);
instance = _sqlExpressionFactory.ApplyTypeMapping(instance, stringTypeMapping);
pattern = _sqlExpressionFactory.ApplyTypeMapping(pattern, stringTypeMapping);
if (pattern is SqlConstantExpression constantExpression)
{
// The pattern is constant. Aside from null or empty, we escape all special characters (%, _, \)
// in C# and send a simple LIKE
if (!(constantExpression.Value is string constantString))
{
return(_sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Constant(null, stringTypeMapping)));
}
return(constantString.Any(c => IsLikeWildChar(c))
? _sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Constant(
startsWith
? EscapeLikePattern(constantString) + '%'
: '%' + EscapeLikePattern(constantString)),
_sqlExpressionFactory.Constant(
LikeEscapeChar.ToString())) // SQL Server has no char mapping, avoid value conversion warning)
: _sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Constant(startsWith ? constantString + '%' : '%' + constantString)));
}
// The pattern is non-constant, we use LEFT or RIGHT to extract substring and compare.
// For StartsWith we also first run a LIKE to quickly filter out most non-matching results (sargable, but imprecise
// because of wildchars).
if (startsWith)
{
return(_sqlExpressionFactory.AndAlso(
_sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Add(
instance,
_sqlExpressionFactory.Constant("%"))),
_sqlExpressionFactory.Equal(
_sqlExpressionFactory.Function(
"LEFT",
new[] { instance, _sqlExpressionFactory.Function("LEN", new[] { pattern }, typeof(int)) },
typeof(string),
stringTypeMapping),
pattern)));
}
return(_sqlExpressionFactory.Equal(
_sqlExpressionFactory.Function(
"RIGHT",
new[] { instance, _sqlExpressionFactory.Function("LEN", new[] { pattern }, typeof(int)) },
typeof(string),
stringTypeMapping),
pattern));
}
private SqlBinaryExpression CreateJoinPredicate(
ShapedQueryExpression outer,
LambdaExpression outerKeySelector,
ShapedQueryExpression inner,
LambdaExpression innerKeySelector)
{
var outerKey = RemapLambdaBody(outer.ShaperExpression, outerKeySelector);
var innerKey = RemapLambdaBody(inner.ShaperExpression, innerKeySelector);
if (outerKey is NewExpression outerNew)
{
var innerNew = (NewExpression)innerKey;
SqlBinaryExpression result = null;
for (var i = 0; i < outerNew.Arguments.Count; i++)
{
result = result == null
? CreateJoinPredicate(outerNew.Arguments[i], innerNew.Arguments[i])
: _sqlExpressionFactory.AndAlso(
result,
CreateJoinPredicate(outerNew.Arguments[i], innerNew.Arguments[i]));
}
return(result);
}
return(CreateJoinPredicate(outerKey, innerKey));
}
SqlExpression TranslateStartsEndsWith(SqlExpression instance, SqlExpression pattern, bool startsWith)
{
var stringTypeMapping = ExpressionExtensions.InferTypeMapping(instance, pattern);
instance = _sqlExpressionFactory.ApplyTypeMapping(instance, stringTypeMapping);
pattern = _sqlExpressionFactory.ApplyTypeMapping(pattern, stringTypeMapping);
if (pattern is SqlConstantExpression constantExpression)
{
// The pattern is constant. Aside from null, we escape all special characters (%, _, \)
// in C# and send a simple LIKE
return(constantExpression.Value is string constantPattern
? _sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Constant(
startsWith
? EscapeLikePattern(constantPattern) + '%'
: '%' + EscapeLikePattern(constantPattern)))
: _sqlExpressionFactory.Like(instance, _sqlExpressionFactory.Constant(null, stringTypeMapping)));
}
// The pattern is non-constant, we use LEFT or RIGHT to extract substring and compare.
// For StartsWith we also first run a LIKE to quickly filter out most non-matching results (sargable, but imprecise
// because of wildchars).
SqlExpression leftRight = _sqlExpressionFactory.Function(
startsWith ? "LEFT" : "RIGHT",
new[]
{
instance,
_sqlExpressionFactory.Function("LENGTH", new[] { pattern }, typeof(int))
},
typeof(string),
stringTypeMapping);
// LEFT/RIGHT of a citext return a text, so for non-default text mappings we apply an explicit cast.
if (instance.TypeMapping != _textTypeMapping)
{
leftRight = _sqlExpressionFactory.Convert(leftRight, typeof(string), instance.TypeMapping);
}
// Also add an explicit cast on the pattern; this is only required because of
// The following is only needed because of https://github.com/aspnet/EntityFrameworkCore/issues/19120
var castPattern = pattern.TypeMapping == _textTypeMapping
? pattern
: _sqlExpressionFactory.Convert(pattern, typeof(string), pattern.TypeMapping);
return(startsWith
? _sqlExpressionFactory.AndAlso(
_sqlExpressionFactory.Like(
instance,
_sqlExpressionFactory.Add(
pattern,
_sqlExpressionFactory.Constant("%"))),
_sqlExpressionFactory.Equal(leftRight, castPattern))
: _sqlExpressionFactory.Equal(leftRight, castPattern));
}
public virtual SqlExpression Translate(SqlExpression instance, MemberInfo member, Type returnType)
{
if (_memberToFunctionName.TryGetValue(member, out var functionName))
{
Debug.Assert(instance.TypeMapping != null, "Instance must have typeMapping assigned.");
var storeType = instance.TypeMapping.StoreType;
var resultTypeMapping = typeof(Geometry).IsAssignableFrom(returnType)
? _typeMappingSource.FindMapping(returnType, storeType)
: _typeMappingSource.FindMapping(returnType);
// Emulate ST_IsRing if not supported.
var sqlExpression = functionName != "ST_IsRing" ||
_options.ServerVersion.SupportsSpatialIsRingFunction
? (SqlExpression)_sqlExpressionFactory.Function(
functionName,
new[] { instance },
returnType,
resultTypeMapping)
: _sqlExpressionFactory.AndAlso(
_sqlExpressionFactory.Function(
"ST_IsClosed",
new[] { instance },
returnType,
resultTypeMapping),
_sqlExpressionFactory.Function(
"ST_IsSimple",
new[] { instance },
returnType,
resultTypeMapping)
);
// ST_IsRing and others returns TRUE for a NULL value in MariaDB, which is inconsistent with NTS' implementation.
// We return the following instead:
// CASE
// WHEN instance IS NULL THEN NULL
// ELSE expression
// END
if (returnType == typeof(bool))
{
sqlExpression = _sqlExpressionFactory.Case(
new[]
{
new CaseWhenClause(
_sqlExpressionFactory.IsNull(instance),
_sqlExpressionFactory.Constant(null, RelationalTypeMapping.NullMapping))
},
sqlExpression);
}
return(sqlExpression);
}
return(null);
}
private SqlBinaryExpression CreateJoinPredicate(
IList <Expression> outerExpressions,
IList <Expression> innerExpressions)
{
SqlBinaryExpression result = null;
for (var i = 0; i < outerExpressions.Count; i++)
{
result = result == null
? CreateJoinPredicate(outerExpressions[i], innerExpressions[i])
: _sqlExpressionFactory.AndAlso(
result,
CreateJoinPredicate(outerExpressions[i], innerExpressions[i]));
}
return(result);
}
/// <inheritdoc/>
public virtual SqlExpression?Translate(
SqlExpression?instance,
MethodInfo method,
IReadOnlyList <SqlExpression> arguments,
IDiagnosticsLogger <DbLoggerCategory.Query> logger)
{
Check.NotNull(method, nameof(method));
Check.NotNull(arguments, nameof(arguments));
Check.NotNull(logger, nameof(logger));
if (_methodInfoDatePartMapping.TryGetValue(method, out var value))
{
var start = _sqlExpressionFactory.GreaterThanOrEqual(arguments[0], arguments[1]);
var end = _sqlExpressionFactory.LessThanOrEqual(arguments[0], arguments[2]);
return(_sqlExpressionFactory.AndAlso(start, end));
}
return(null);
}
public override Expression Visit(Expression expression)
{
if (expression is InExpression inExpression &&
inExpression.Values != null)
{
var inValues = new List <object>();
var hasNullValue = false;
RelationalTypeMapping typeMapping = null;
switch (inExpression.Values)
{
case SqlConstantExpression sqlConstant:
{
typeMapping = sqlConstant.TypeMapping;
var values = (IEnumerable)sqlConstant.Value;
foreach (var value in values)
{
if (value == null)
{
hasNullValue = true;
continue;
}
inValues.Add(value);
}
}
break;
case SqlParameterExpression sqlParameter:
{
typeMapping = sqlParameter.TypeMapping;
var values = (IEnumerable)_parametersValues[sqlParameter.Name];
foreach (var value in values)
{
if (value == null)
{
hasNullValue = true;
continue;
}
inValues.Add(value);
}
}
break;
}
var updatedInExpression = inValues.Count > 0
? _sqlExpressionFactory.In(
(SqlExpression)Visit(inExpression.Item),
_sqlExpressionFactory.Constant(inValues, typeMapping),
inExpression.Negated)
: null;
var nullCheckExpression = hasNullValue
? inExpression.Negated
? _sqlExpressionFactory.IsNotNull(inExpression.Item)
: _sqlExpressionFactory.IsNull(inExpression.Item)
: null;
if (updatedInExpression != null && nullCheckExpression != null)
{
return(inExpression.Negated
? _sqlExpressionFactory.AndAlso(updatedInExpression, nullCheckExpression)
: _sqlExpressionFactory.OrElse(updatedInExpression, nullCheckExpression));
}
if (updatedInExpression == null && nullCheckExpression == null)
{
return(_sqlExpressionFactory.Equal(_sqlExpressionFactory.Constant(true), _sqlExpressionFactory.Constant(inExpression.Negated)));
}
return((SqlExpression)updatedInExpression ?? nullCheckExpression);
}
return(base.Visit(expression));
}
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
public virtual SqlExpression?Translate(
SqlExpression?instance,
MethodInfo method,
IReadOnlyList <SqlExpression> arguments,
IDiagnosticsLogger <DbLoggerCategory.Query> logger)
{
if (instance != null)
{
if (MethodToFunctionName.TryGetValue(method, out var functionName))
{
var finalArguments = new[] { instance }.Concat(arguments);
if (method.ReturnType == typeof(bool))
{
var nullCheck = (SqlExpression)_sqlExpressionFactory.IsNotNull(instance);
foreach (var argument in arguments)
{
nullCheck = _sqlExpressionFactory.AndAlso(
nullCheck,
_sqlExpressionFactory.IsNotNull(argument));
}
return(_sqlExpressionFactory.Case(
new[]
{
new CaseWhenClause(
nullCheck,
_sqlExpressionFactory.Function(
functionName,
finalArguments,
nullable: false,
finalArguments.Select(a => false),
method.ReturnType))
},
null));
}
return(_sqlExpressionFactory.Function(
functionName,
finalArguments,
nullable: true,
finalArguments.Select(a => true),
method.ReturnType));
}
if (Equals(method, GetGeometryN))
{
return(_sqlExpressionFactory.Function(
"GeometryN",
new[]
{
instance,
_sqlExpressionFactory.Add(
arguments[0],
_sqlExpressionFactory.Constant(1))
},
nullable: true,
argumentsPropagateNullability: new[] { true, true },
method.ReturnType));
}
if (Equals(method, IsWithinDistance))
{
return(_sqlExpressionFactory.LessThanOrEqual(
_sqlExpressionFactory.Function(
"Distance",
new[] { instance, arguments[0] },
nullable: true,
argumentsPropagateNullability: new[] { true, true },
typeof(double)),
arguments[1]));
}
}
return(null);
}
private Expression VisitSqlUnaryExpression(SqlUnaryExpression sqlUnaryExpression)
{
// !(true) -> false
// !(false) -> true
if (sqlUnaryExpression.OperatorType == ExpressionType.Not &&
sqlUnaryExpression.Operand is SqlConstantExpression innerConstantBool &&
innerConstantBool.Value is bool value)
{
return(value
? _sqlExpressionFactory.Constant(false, sqlUnaryExpression.TypeMapping)
: _sqlExpressionFactory.Constant(true, sqlUnaryExpression.TypeMapping));
}
// NULL IS NULL -> true
// non_nullablee_constant IS NULL -> false
if (sqlUnaryExpression.OperatorType == ExpressionType.Equal &&
sqlUnaryExpression.Operand is SqlConstantExpression innerConstantNull1)
{
return(_sqlExpressionFactory.Constant(innerConstantNull1.Value == null, sqlUnaryExpression.TypeMapping));
}
// NULL IS NOT NULL -> false
// non_nullablee_constant IS NOT NULL -> true
if (sqlUnaryExpression.OperatorType == ExpressionType.NotEqual &&
sqlUnaryExpression.Operand is SqlConstantExpression innerConstantNull2)
{
return(_sqlExpressionFactory.Constant(innerConstantNull2.Value != null, sqlUnaryExpression.TypeMapping));
}
if (sqlUnaryExpression.Operand is SqlUnaryExpression innerUnary)
{
if (sqlUnaryExpression.OperatorType == ExpressionType.Not)
{
// !(!a) -> a
if (innerUnary.OperatorType == ExpressionType.Not)
{
return(Visit(innerUnary.Operand));
}
if (innerUnary.OperatorType == ExpressionType.Equal)
{
//!(a IS NULL) -> a IS NOT NULL
return(Visit(_sqlExpressionFactory.IsNotNull(innerUnary.Operand)));
}
//!(a IS NOT NULL) -> a IS NULL
if (innerUnary.OperatorType == ExpressionType.NotEqual)
{
return(Visit(_sqlExpressionFactory.IsNull(innerUnary.Operand)));
}
}
// (!a) IS NULL <==> a IS NULL
if (sqlUnaryExpression.OperatorType == ExpressionType.Equal &&
innerUnary.OperatorType == ExpressionType.Not)
{
return(Visit(_sqlExpressionFactory.IsNull(innerUnary.Operand)));
}
// (!a) IS NOT NULL <==> a IS NOT NULL
if (sqlUnaryExpression.OperatorType == ExpressionType.NotEqual &&
innerUnary.OperatorType == ExpressionType.Not)
{
return(Visit(_sqlExpressionFactory.IsNotNull(innerUnary.Operand)));
}
}
if (sqlUnaryExpression.Operand is SqlBinaryExpression innerBinary)
{
// De Morgan's
if (innerBinary.OperatorType == ExpressionType.AndAlso ||
innerBinary.OperatorType == ExpressionType.OrElse)
{
var newLeft = (SqlExpression)Visit(_sqlExpressionFactory.Not(innerBinary.Left));
var newRight = (SqlExpression)Visit(_sqlExpressionFactory.Not(innerBinary.Right));
return(innerBinary.OperatorType == ExpressionType.AndAlso
? _sqlExpressionFactory.OrElse(newLeft, newRight)
: _sqlExpressionFactory.AndAlso(newLeft, newRight));
}
// note that those optimizations are only valid in 2-value logic
// they are safe to do here because null semantics removes possibility of nulls in the tree
// however if we decide to do "partial" null semantics (that doesn't distinguish between NULL and FALSE, e.g. for predicates)
// we need to be extra careful here
if (TryNegate(innerBinary.OperatorType, out var negated))
{
return(Visit(
_sqlExpressionFactory.MakeBinary(
negated,
innerBinary.Left,
innerBinary.Right,
innerBinary.TypeMapping)));
}
}
var newOperand = (SqlExpression)Visit(sqlUnaryExpression.Operand);
return(sqlUnaryExpression.Update(newOperand));
}
protected override Expression VisitSqlBinary(SqlBinaryExpression sqlBinaryExpression)
{
Check.NotNull(sqlBinaryExpression, nameof(sqlBinaryExpression));
_isNullable = false;
var canOptimize = _canOptimize;
// for SqlServer we could also allow optimize on children of ExpressionType.Equal
// because they get converted to CASE blocks anyway, but for other providers it's incorrect
// once/if null semantics optimizations are provider-specific we can enable it
_canOptimize = _canOptimize && (sqlBinaryExpression.OperatorType == ExpressionType.AndAlso ||
sqlBinaryExpression.OperatorType == ExpressionType.OrElse);
var nonNullableColumns = new List <ColumnExpression>();
if (sqlBinaryExpression.OperatorType == ExpressionType.AndAlso)
{
nonNullableColumns = FindNonNullableColumns(sqlBinaryExpression.Left);
}
var newLeft = (SqlExpression)Visit(sqlBinaryExpression.Left);
var leftNullable = _isNullable;
_isNullable = false;
if (nonNullableColumns.Count > 0)
{
_nonNullableColumns.AddRange(nonNullableColumns);
}
var newRight = (SqlExpression)Visit(sqlBinaryExpression.Right);
var rightNullable = _isNullable;
foreach (var nonNullableColumn in nonNullableColumns)
{
_nonNullableColumns.Remove(nonNullableColumn);
}
if (sqlBinaryExpression.OperatorType == ExpressionType.Coalesce)
{
_isNullable = leftNullable && rightNullable;
_canOptimize = canOptimize;
return(sqlBinaryExpression.Update(newLeft, newRight));
}
if (sqlBinaryExpression.OperatorType == ExpressionType.Add &&
sqlBinaryExpression.Type == typeof(string))
{
if (leftNullable)
{
newLeft = newLeft is SqlConstantExpression
? _sqlExpressionFactory.Constant(string.Empty)
: newLeft is ColumnExpression || newLeft is SqlParameterExpression
? _sqlExpressionFactory.Coalesce(newLeft, _sqlExpressionFactory.Constant(string.Empty))
: newLeft;
}
if (rightNullable)
{
newRight = newRight is SqlConstantExpression
? _sqlExpressionFactory.Constant(string.Empty)
: newRight is ColumnExpression || newRight is SqlParameterExpression
? _sqlExpressionFactory.Coalesce(newRight, _sqlExpressionFactory.Constant(string.Empty))
: newRight;
}
return(sqlBinaryExpression.Update(newLeft, newRight));
}
if (sqlBinaryExpression.OperatorType == ExpressionType.Equal ||
sqlBinaryExpression.OperatorType == ExpressionType.NotEqual)
{
var leftConstantNull = newLeft is SqlConstantExpression leftConstant && leftConstant.Value == null;
var rightConstantNull = newRight is SqlConstantExpression rightConstant && rightConstant.Value == null;
// a == null -> a IS NULL
// a != null -> a IS NOT NULL
if (rightConstantNull)
{
_isNullable = false;
_canOptimize = canOptimize;
return(sqlBinaryExpression.OperatorType == ExpressionType.Equal
? _sqlExpressionFactory.IsNull(newLeft)
: _sqlExpressionFactory.IsNotNull(newLeft));
}
// null == a -> a IS NULL
// null != a -> a IS NOT NULL
if (leftConstantNull)
{
_isNullable = false;
_canOptimize = canOptimize;
return(sqlBinaryExpression.OperatorType == ExpressionType.Equal
? _sqlExpressionFactory.IsNull(newRight)
: _sqlExpressionFactory.IsNotNull(newRight));
}
var leftUnary = newLeft as SqlUnaryExpression;
var rightUnary = newRight as SqlUnaryExpression;
var leftNegated = leftUnary?.IsLogicalNot() == true;
var rightNegated = rightUnary?.IsLogicalNot() == true;
if (leftNegated)
{
newLeft = leftUnary.Operand;
}
if (rightNegated)
{
newRight = rightUnary.Operand;
}
var leftIsNull = _sqlExpressionFactory.IsNull(newLeft);
var rightIsNull = _sqlExpressionFactory.IsNull(newRight);
// optimized expansion which doesn't distinguish between null and false
if (canOptimize &&
sqlBinaryExpression.OperatorType == ExpressionType.Equal &&
!leftNegated &&
!rightNegated)
{
// when we use optimized form, the result can still be nullable
if (leftNullable && rightNullable)
{
_isNullable = true;
_canOptimize = canOptimize;
return(_sqlExpressionFactory.OrElse(
_sqlExpressionFactory.Equal(newLeft, newRight),
_sqlExpressionFactory.AndAlso(leftIsNull, rightIsNull)));
}
if ((leftNullable && !rightNullable) ||
(!leftNullable && rightNullable))
{
_isNullable = true;
_canOptimize = canOptimize;
return(_sqlExpressionFactory.Equal(newLeft, newRight));
}
}
// doing a full null semantics rewrite - removing all nulls from truth table
// this will NOT be correct once we introduce simplified null semantics
_isNullable = false;
_canOptimize = canOptimize;
if (sqlBinaryExpression.OperatorType == ExpressionType.Equal)
{
if (!leftNullable &&
!rightNullable)
{
// a == b <=> !a == !b -> a == b
// !a == b <=> a == !b -> a != b
return(leftNegated == rightNegated
? _sqlExpressionFactory.Equal(newLeft, newRight)
: _sqlExpressionFactory.NotEqual(newLeft, newRight));
}
if (leftNullable && rightNullable)
{
// ?a == ?b <=> !(?a) == !(?b) -> [(a == b) && (a != null && b != null)] || (a == null && b == null))
// !(?a) == ?b <=> ?a == !(?b) -> [(a != b) && (a != null && b != null)] || (a == null && b == null)
return(leftNegated == rightNegated
? ExpandNullableEqualNullable(newLeft, newRight, leftIsNull, rightIsNull)
: ExpandNegatedNullableEqualNullable(newLeft, newRight, leftIsNull, rightIsNull));
}
if (leftNullable && !rightNullable)
{
// ?a == b <=> !(?a) == !b -> (a == b) && (a != null)
// !(?a) == b <=> ?a == !b -> (a != b) && (a != null)
return(leftNegated == rightNegated
? ExpandNullableEqualNonNullable(newLeft, newRight, leftIsNull)
: ExpandNegatedNullableEqualNonNullable(newLeft, newRight, leftIsNull));
}
if (rightNullable && !leftNullable)
{
// a == ?b <=> !a == !(?b) -> (a == b) && (b != null)
// !a == ?b <=> a == !(?b) -> (a != b) && (b != null)
return(leftNegated == rightNegated
? ExpandNullableEqualNonNullable(newLeft, newRight, rightIsNull)
: ExpandNegatedNullableEqualNonNullable(newLeft, newRight, rightIsNull));
}
}
if (sqlBinaryExpression.OperatorType == ExpressionType.NotEqual)
{
if (!leftNullable &&
!rightNullable)
{
// a != b <=> !a != !b -> a != b
// !a != b <=> a != !b -> a == b
return(leftNegated == rightNegated
? _sqlExpressionFactory.NotEqual(newLeft, newRight)
: _sqlExpressionFactory.Equal(newLeft, newRight));
}
if (leftNullable && rightNullable)
{
// ?a != ?b <=> !(?a) != !(?b) -> [(a != b) || (a == null || b == null)] && (a != null || b != null)
// !(?a) != ?b <=> ?a != !(?b) -> [(a == b) || (a == null || b == null)] && (a != null || b != null)
return(leftNegated == rightNegated
? ExpandNullableNotEqualNullable(newLeft, newRight, leftIsNull, rightIsNull)
: ExpandNegatedNullableNotEqualNullable(newLeft, newRight, leftIsNull, rightIsNull));
}
if (leftNullable)
{
// ?a != b <=> !(?a) != !b -> (a != b) || (a == null)
// !(?a) != b <=> ?a != !b -> (a == b) || (a == null)
return(leftNegated == rightNegated
? ExpandNullableNotEqualNonNullable(newLeft, newRight, leftIsNull)
: ExpandNegatedNullableNotEqualNonNullable(newLeft, newRight, leftIsNull));
}
if (rightNullable)
{
// a != ?b <=> !a != !(?b) -> (a != b) || (b == null)
// !a != ?b <=> a != !(?b) -> (a == b) || (b == null)
return(leftNegated == rightNegated
? ExpandNullableNotEqualNonNullable(newLeft, newRight, rightIsNull)
: ExpandNegatedNullableNotEqualNonNullable(newLeft, newRight, rightIsNull));
}
}
}
_isNullable = leftNullable || rightNullable;
_canOptimize = canOptimize;
return(sqlBinaryExpression.Update(newLeft, newRight));
}
public virtual SqlExpression Translate(SqlExpression instance, MethodInfo method, IReadOnlyList <SqlExpression> arguments)
{
Check.NotNull(method, nameof(method));
Check.NotNull(arguments, nameof(arguments));
if (_methodToFunctionName.TryGetValue(method, out var functionName))
{
var finalArguments = new[] { instance }.Concat(arguments);
if (method.ReturnType == typeof(bool))
{
var nullCheck = (SqlExpression)_sqlExpressionFactory.IsNotNull(instance);
foreach (var argument in arguments)
{
nullCheck = _sqlExpressionFactory.AndAlso(
nullCheck,
_sqlExpressionFactory.IsNotNull(argument));
}
return(_sqlExpressionFactory.Case(
new[]
{
new CaseWhenClause(
nullCheck,
_sqlExpressionFactory.Function(
functionName,
finalArguments,
nullResultAllowed: false,
finalArguments.Select(a => false),
method.ReturnType))
},
null));
}
return(_sqlExpressionFactory.Function(
functionName,
finalArguments,
nullResultAllowed: true,
finalArguments.Select(a => true),
method.ReturnType));
}
if (Equals(method, _getGeometryN))
{
return(_sqlExpressionFactory.Function(
"GeometryN",
new[]
{
instance,
_sqlExpressionFactory.Add(
arguments[0],
_sqlExpressionFactory.Constant(1))
},
nullResultAllowed: true,
argumentsPropagateNullability: new[] { true, true },
method.ReturnType));
}
if (Equals(method, _isWithinDistance))
{
return(_sqlExpressionFactory.LessThanOrEqual(
_sqlExpressionFactory.Function(
"Distance",
new[] { instance, arguments[0] },
nullResultAllowed: true,
argumentsPropagateNullability: new[] { true, true },
typeof(double)),
arguments[1]));
}
return(null);
}
private static SqlExpression GetAndoyerDistance(
SqlExpression left,
SqlExpression right,
Type resultType,
ISqlExpressionFactory sqlExpressionFactory)
{
SqlExpression toDegrees(SqlExpression coord)
=> sqlExpressionFactory.Divide(
sqlExpressionFactory.Multiply(
coord,
sqlExpressionFactory.Function(
"PI",
Array.Empty <SqlExpression>(),
resultType)),
sqlExpressionFactory.Constant(180.0));
SqlExpression xCoord(SqlExpression point)
=> sqlExpressionFactory.Function(
"ST_X",
new[] { point },
resultType);
SqlExpression yCoord(SqlExpression point)
=> sqlExpressionFactory.Function(
"ST_Y",
new[] { point },
resultType);
var c0 = sqlExpressionFactory.Constant(0.0);
var c1 = sqlExpressionFactory.Constant(1.0);
var c2 = sqlExpressionFactory.Constant(2.0);
var c3 = sqlExpressionFactory.Constant(3.0);
var c2Int = sqlExpressionFactory.Constant(2);
var lon1 = toDegrees(xCoord(left));
var lat1 = toDegrees(yCoord(left));
var lon2 = toDegrees(xCoord(right));
var lat2 = toDegrees(yCoord(right));
var g = sqlExpressionFactory.Divide(
sqlExpressionFactory.Subtract(
lat1,
lat2),
c2);
var lambda = sqlExpressionFactory.Divide(
sqlExpressionFactory.Subtract(
lon1,
lon2),
c2);
var f = sqlExpressionFactory.Divide(
sqlExpressionFactory.Add(
lat1,
lat2),
c2);
var sinG2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"SIN",
new[] { g },
resultType),
c2Int
},
resultType);
var cosG2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"COS",
new[] { g },
resultType),
c2Int
},
resultType);
var sinF2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"SIN",
new[] { f },
resultType),
c2Int
},
resultType);
var cosF2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"COS",
new[] { f },
resultType),
c2Int
},
resultType);
var sinL2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"SIN",
new[] { lambda },
resultType),
c2Int
},
resultType);
var cosL2 = sqlExpressionFactory.Function(
"POWER",
new SqlExpression[]
{
sqlExpressionFactory.Function(
"COS",
new[] { lambda },
resultType),
c2Int
},
resultType);
var s = sqlExpressionFactory.Add(
sqlExpressionFactory.Multiply(sinG2, cosL2),
sqlExpressionFactory.Multiply(cosF2, sinL2));
var c = sqlExpressionFactory.Add(
sqlExpressionFactory.Multiply(cosG2, cosL2),
sqlExpressionFactory.Multiply(sinF2, sinL2));
var radiusA = sqlExpressionFactory.Constant(6378137.0);
var radiusB = sqlExpressionFactory.Constant(6356752.3142451793);
var flattening = sqlExpressionFactory.Divide(
sqlExpressionFactory.Subtract(radiusA, radiusB),
radiusA);
var omega = sqlExpressionFactory.Function(
"ATAN",
new[]
{
sqlExpressionFactory.Function(
"SQRT",
new[] { sqlExpressionFactory.Divide(s, c) },
resultType)
},
resultType);
var r3 = sqlExpressionFactory.Divide(
sqlExpressionFactory.Multiply(
c3,
sqlExpressionFactory.Function(
"SQRT",
new[] { sqlExpressionFactory.Multiply(s, c) },
resultType)),
omega);
var d = sqlExpressionFactory.Multiply(
sqlExpressionFactory.Multiply(c2, omega),
radiusA);
var h1 = sqlExpressionFactory.Divide(
sqlExpressionFactory.Subtract(r3, c1),
sqlExpressionFactory.Multiply(c2, c));
var h2 = sqlExpressionFactory.Divide(
sqlExpressionFactory.Add(r3, c1),
sqlExpressionFactory.Multiply(c2, s));
var andoyer = sqlExpressionFactory.Multiply(
d,
sqlExpressionFactory.Add(
c1,
sqlExpressionFactory.Multiply(
flattening,
sqlExpressionFactory.Subtract(
sqlExpressionFactory.Multiply(
sqlExpressionFactory.Multiply(
h1,
sinF2),
cosG2),
sqlExpressionFactory.Multiply(
sqlExpressionFactory.Multiply(
h2,
cosF2),
sinG2)))));
return(sqlExpressionFactory.Case(
new[]
{
new CaseWhenClause(
sqlExpressionFactory.OrElse(
sqlExpressionFactory.OrElse(
sqlExpressionFactory.AndAlso(
sqlExpressionFactory.Equal(lambda, c0),
sqlExpressionFactory.Equal(g, c0)),
sqlExpressionFactory.Equal(s, c0)),
sqlExpressionFactory.Equal(c, c0)),
c0),
},
andoyer));
}