should be it

external/duckdb/extension/json/json_functions/json_exists.cpp

@@ -0,0 +1,32 @@
+#include "json_executors.hpp"
+
+namespace duckdb {
+
+static inline bool JSONExists(yyjson_val *val, yyjson_alc *, Vector &, ValidityMask &, idx_t) {
+	return val;
+}
+
+static void BinaryExistsFunction(DataChunk &args, ExpressionState &state, Vector &result) {
+	JSONExecutors::BinaryExecute<bool, false>(args, state, result, JSONExists);
+}
+
+static void ManyExistsFunction(DataChunk &args, ExpressionState &state, Vector &result) {
+	JSONExecutors::ExecuteMany<bool, false>(args, state, result, JSONExists);
+}
+
+static void GetExistsFunctionsInternal(ScalarFunctionSet &set, const LogicalType &input_type) {
+	set.AddFunction(ScalarFunction({input_type, LogicalType::VARCHAR}, LogicalType::BOOLEAN, BinaryExistsFunction,
+	                               JSONReadFunctionData::Bind, nullptr, nullptr, JSONFunctionLocalState::Init));
+	set.AddFunction(ScalarFunction({input_type, LogicalType::LIST(LogicalType::VARCHAR)},
+	                               LogicalType::LIST(LogicalType::BOOLEAN), ManyExistsFunction,
+	                               JSONReadManyFunctionData::Bind, nullptr, nullptr, JSONFunctionLocalState::Init));
+}
+
+ScalarFunctionSet JSONFunctions::GetExistsFunction() {
+	ScalarFunctionSet set("json_exists");
+	GetExistsFunctionsInternal(set, LogicalType::VARCHAR);
+	GetExistsFunctionsInternal(set, LogicalType::JSON());
+	return set;
+}
+
+} // namespace duckdb