types: fix compare float64 with float64 in json (#21709)

Signed-off-by: lzmhhh123 <lzmhhh123@gmail.com>
pingcap · Dec 15, 2020 · b0d9934 · b0d9934
1 parent 8935ad1
commit b0d9934
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -4404,6 +4404,13 @@ func (s *testIntegrationSuite) TestFuncJSON(c *C) {
 
 	// #16267
 	tk.MustQuery(`select json_array(922337203685477580) =  json_array(922337203685477581);`).Check(testkit.Rows("0"))
+
+	// #10461
+	tk.MustExec("drop table if exists tx1")
+	tk.MustExec("create table tx1(id int key, a double, b double, c double, d double)")
+	tk.MustExec("insert into tx1 values (1, 0.1, 0.2, 0.3, 0.0)")
+	tk.MustQuery("select a+b, c from tx1").Check(testkit.Rows("0.30000000000000004 0.3"))
+	tk.MustQuery("select json_array(a+b) = json_array(c) from tx1").Check(testkit.Rows("0"))
 }
 
 func (s *testIntegrationSuite) TestColumnInfoModified(c *C) {

diff --git a/types/json/binary_functions.go b/types/json/binary_functions.go
@@ -647,6 +647,16 @@ func compareInt64(x int64, y int64) int {
 	return 1
 }
 
+func compareFloat64(x float64, y float64) int {
+	if x < y {
+		return -1
+	} else if x == y {
+		return 0
+	}
+
+	return 1
+}
+
 func compareUint64(x uint64, y uint64) int {
 	if x < y {
 		return -1
@@ -712,7 +722,7 @@ func CompareBinary(left, right BinaryJSON) int {
 			case TypeCodeUint64:
 				cmp = compareFloat64Uint64(left.GetFloat64(), right.GetUint64())
 			case TypeCodeFloat64:
-				cmp = compareFloat64PrecisionLoss(left.GetFloat64(), right.GetFloat64())
+				cmp = compareFloat64(left.GetFloat64(), right.GetFloat64())
 			}
 		case TypeCodeString:
 			cmp = bytes.Compare(left.GetString(), right.GetString())