protected override Expression VisitBinary(BinaryExpression binaryExpression)
{
if (binaryExpression.NodeType == ExpressionType.ArrayIndex)
{
if (TranslationFailed(binaryExpression.Left, Visit(TryRemoveImplicitConvert(binaryExpression.Left)), out var sqlLeft) ||
TranslationFailed(binaryExpression.Right, Visit(TryRemoveImplicitConvert(binaryExpression.Right)), out var sqlRight))
{
return(null);
}
// Try translating ArrayIndex inside json column
return(_jsonPocoTranslator.TranslateMemberAccess(
sqlLeft,
_sqlExpressionFactory.JsonArrayIndex(sqlRight),
binaryExpression.Type));
}
var visitedExpression = (SqlExpression)base.VisitBinary(binaryExpression);
if (visitedExpression == null)
{
return(null);
}
if (visitedExpression is SqlBinaryExpression visitedBinaryExpression)
{
// Returning null forces client projection.
// CHECK: Is this still true in .NET Core 3.0?
switch (visitedBinaryExpression.OperatorType)
{
case ExpressionType.Add:
case ExpressionType.Subtract:
case ExpressionType.Multiply:
case ExpressionType.Divide:
case ExpressionType.Modulo:
return(IsDateTimeBasedOperation(visitedBinaryExpression)
? null
: visitedBinaryExpression);
}
// The following section might not be needed. Lets keep it for a bit, until we are sure.
/*
* // When comparing a JSON value to some string value or when assigning a string value
* // to a JSON column, convert the string value to JSON first.
* // Also explicitly convert parameter instances to JSON.
* if (visitedBinaryExpression.Left.TypeMapping?.StoreType == "json" &&
* visitedBinaryExpression.Right.TypeMapping?.StoreType != "json" &&
* visitedBinaryExpression.Right.TypeMapping?.ClrType == typeof(string))
* {
* visitedExpression = _sqlExpressionFactory.MakeBinary(
* visitedBinaryExpression.OperatorType,
* visitedBinaryExpression.Left,
* _sqlExpressionFactory.Convert(
* visitedBinaryExpression.Right,
* visitedBinaryExpression.Right.Type,
* _jsonTypeMapping),
* _jsonTypeMapping);
* }
* else if (visitedBinaryExpression.Right.TypeMapping?.StoreType == "json" &&
* visitedBinaryExpression.Left.TypeMapping?.StoreType != "json" &&
* visitedBinaryExpression.Left.TypeMapping?.ClrType == typeof(string) &&
* visitedBinaryExpression.OperatorType != ExpressionType.Assign)
* {
* visitedExpression = _sqlExpressionFactory.MakeBinary(
* visitedBinaryExpression.OperatorType,
* _sqlExpressionFactory.Convert(
* visitedBinaryExpression.Left,
* visitedBinaryExpression.Left.Type,
* _jsonTypeMapping),
* visitedBinaryExpression.Right,
* _jsonTypeMapping);
* }
*/
}
return(visitedExpression);
}
public SqlExpression Translate(SqlExpression instance, MethodInfo method, IReadOnlyList <SqlExpression> arguments, IDiagnosticsLogger <DbLoggerCategory.Query> logger)
{
if (instance != null && instance.Type.IsGenericList() && method.Name == "get_Item" && arguments.Count == 1)
{
// Try translating indexing inside json column
return(_jsonPocoTranslator.TranslateMemberAccess(instance, arguments[0], method.ReturnType));
}
// Predicate-less Any - translate to a simple length check.
if (method.IsClosedFormOf(_enumerableAnyWithoutPredicate) &&
arguments.Count == 1 &&
arguments[0].Type.TryGetElementType(out _) &&
arguments[0].TypeMapping is MySqlJsonTypeMapping)
{
return(_sqlExpressionFactory.GreaterThan(
_jsonPocoTranslator.TranslateArrayLength(arguments[0]),
_sqlExpressionFactory.Constant(0)));
}
if (method.DeclaringType != typeof(JsonElement) ||
!(instance.TypeMapping is MySqlJsonTypeMapping mapping))
{
return(null);
}
// The root of the JSON expression is a ColumnExpression. We wrap that with an empty traversal
// expression (col->'$'); subsequent traversals will gradually append the path into that.
// Note that it's possible to call methods such as GetString() directly on the root, and the
// empty traversal is necessary to properly convert it to a text.
instance = instance is ColumnExpression columnExpression
? _sqlExpressionFactory.JsonTraversal(
columnExpression, returnsText : false, typeof(string), mapping)
: instance;
if (method == _getProperty)
{
return(instance is MySqlJsonTraversalExpression prevPathTraversal
? prevPathTraversal.Append(
ApplyPathLocationTypeMapping(arguments[0]),
typeof(JsonElement),
_typeMappingSource.FindMapping(typeof(JsonElement)))
: null);
}
if (method == _arrayIndexer)
{
return(instance is MySqlJsonTraversalExpression prevPathTraversal
? prevPathTraversal.Append(
_sqlExpressionFactory.JsonArrayIndex(ApplyPathLocationTypeMapping(arguments[0])),
typeof(JsonElement),
_typeMappingSource.FindMapping(typeof(JsonElement)))
: null);
}
if (_getMethods.Contains(method.Name) &&
arguments.Count == 0 &&
instance is MySqlJsonTraversalExpression traversal)
{
return(ConvertFromJsonExtract(
traversal.Clone(
method.Name == nameof(JsonElement.GetString),
method.ReturnType,
_typeMappingSource.FindMapping(method.ReturnType)
),
method.ReturnType));
}
if (method == _getArrayLength)
{
// Could return NULL if the path is not found, but we would be alright to throw then.
return(_sqlExpressionFactory.NullableFunction(
"JSON_LENGTH",
new[] { instance },
typeof(int),
false));
}
if (method.Name.StartsWith("TryGet") && arguments.Count == 0)
{
throw new InvalidOperationException($"The TryGet* methods on {nameof(JsonElement)} aren't translated yet, use Get* instead.'");
}
return(null);
}
public virtual SqlExpression Translate(SqlExpression instance, MethodInfo method, IReadOnlyList <SqlExpression> arguments)
{
var traversal = GetTraversalExpression(instance, arguments);
if (traversal == null)
{
return(null);
}
if (typeof(JToken).IsAssignableFrom(method.DeclaringType) &&
method.Name == "get_Item" &&
arguments.Count == 1)
{
var indexExpression = _sqlExpressionFactory.ApplyDefaultTypeMapping(arguments[0]);
if (method.DeclaringType == typeof(JArray) ||
indexExpression.Type == typeof(int))
{
// Try translating indexing inside json column.
return(_jsonPocoTranslator.TranslateMemberAccess(
traversal,
_sqlExpressionFactory.JsonArrayIndex(indexExpression),
method.ReturnType));
}
return(traversal.Append(
ApplyPathLocationTypeMapping(arguments[0]),
method.DeclaringType,
_typeMappingSource.FindMapping(method.DeclaringType)));
}
// Support for .Value<T>() and .Value<U, T>():
if (instance == null &&
method.Name == nameof(global::Newtonsoft.Json.Linq.Extensions.Value) &&
method.DeclaringType == typeof(global::Newtonsoft.Json.Linq.Extensions) &&
method.IsGenericMethod &&
method.GetParameters().Length == 1 &&
arguments.Count == 1)
{
return(ConvertFromJsonExtract(
traversal.Clone(
method.ReturnType == typeof(string),
method.ReturnType,
_typeMappingSource.FindMapping(method.ReturnType)
),
method.ReturnType));
}
// Support for Count()
if (instance == null &&
method.Name == nameof(Enumerable.Count) &&
method.DeclaringType == typeof(Enumerable) &&
method.IsGenericMethod &&
method.GetParameters().Length == 1 &&
arguments.Count == 1)
{
return(_jsonPocoTranslator.TranslateArrayLength(traversal));
}
// Predicate-less Any - translate to a simple length check.
if (method.IsClosedFormOf(_enumerableAnyWithoutPredicate) &&
arguments.Count == 1 &&
arguments[0].Type.TryGetElementType(out _) &&
arguments[0].TypeMapping is MySqlJsonTypeMapping)
{
return(_sqlExpressionFactory.GreaterThan(
_jsonPocoTranslator.TranslateArrayLength(arguments[0]),
_sqlExpressionFactory.Constant(0)));
}
return(null);
}