Merge pull request #19960 from ClickHouse/json-extract-inaccurate-conversion-from-double-to-float

Allow inaccurate conversion from double to float in function JSONExtract beacuse the users want that

src/Functions/FunctionsJSON.h

@@ -25,6 +25,7 @@
 #include <DataTypes/DataTypeTuple.h>
 #include <Interpreters/Context.h>
 #include <ext/range.h>
+#include <type_traits>
 #include <boost/tti/has_member_function.hpp>
 
 #if !defined(ARCADIA_BUILD)
@@ -507,11 +508,20 @@ public:
         }
         else if (element.isDouble())
         {
-            if (!accurate::convertNumeric(element.getDouble(), value))
+            if constexpr (std::is_floating_point_v<NumberType>)
+            {
+                /// We permit inaccurate conversion of double to float.
+                /// Example: double 0.1 from JSON is not representable in float.
+                /// But it will be more convenient for user to perform conversion.
+                value = element.getDouble();
+            }
+            else if (!accurate::convertNumeric(element.getDouble(), value))
                 return false;
         }
         else if (element.isBool() && is_integer_v<NumberType> && convert_bool_to_integer)
+        {
             value = static_cast<NumberType>(element.getBool());
+        }
         else
             return false;
 

tests/queries/0_stateless/01685_json_extract_double_as_float.reference

+1.1	1.1	1.1	1.1
+0.01	0.01	0.01	0.01
+0
+\N
+-1e300
+-inf
+0
+0
+0
+0

tests/queries/0_stateless/01685_json_extract_double_as_float.sql

+WITH '{ "v":1.1}' AS raw
+SELECT
+    JSONExtract(raw, 'v', 'float') AS float32_1,
+    JSONExtract(raw, 'v', 'Float32') AS float32_2,
+    JSONExtractFloat(raw, 'v') AS float64_1,
+    JSONExtract(raw, 'v', 'double') AS float64_2;
+
+WITH '{ "v":1E-2}' AS raw
+SELECT
+    JSONExtract(raw, 'v', 'float') AS float32_1,
+    JSONExtract(raw, 'v', 'Float32') AS float32_2,
+    JSONExtractFloat(raw, 'v') AS float64_1,
+    JSONExtract(raw, 'v', 'double') AS float64_2;
+
+SELECT JSONExtract('{"v":1.1}', 'v', 'UInt64');
+SELECT JSONExtract('{"v":1.1}', 'v', 'Nullable(UInt64)');
+
+SELECT JSONExtract('{"v":-1e300}', 'v', 'Float64');
+SELECT JSONExtract('{"v":-1e300}', 'v', 'Float32');
+
+SELECT JSONExtract('{"v":-1e300}', 'v', 'UInt64');
+SELECT JSONExtract('{"v":-1e300}', 'v', 'Int64');
+SELECT JSONExtract('{"v":-1e300}', 'v', 'UInt8');
+SELECT JSONExtract('{"v":-1e300}', 'v', 'Int8');