fix error if json value is negative float

src/client/src/tscUtil.c

@@ -5560,7 +5560,7 @@ end:
 int8_t jsonType2DbType(double data, int jsonType){
   switch(jsonType){
     case cJSON_Number:
-      if (data - (int64_t)data > 0) return TSDB_DATA_TYPE_DOUBLE; else return TSDB_DATA_TYPE_BIGINT;
+      if (data - (int64_t)data == 0) return TSDB_DATA_TYPE_BIGINT; else return TSDB_DATA_TYPE_DOUBLE;
     case cJSON_String:
       return TSDB_DATA_TYPE_NCHAR;
     case cJSON_NULL:

tests/develop-test/0-management/3-tag/json_tag.py

@@ -16,6 +16,7 @@ import taos
 from util.log import tdLog
 from util.cases import tdCases
 from util.sql import tdSql
+import json
 
 
 class TDTestCase:
@@ -505,6 +506,11 @@ class TDTestCase:
         tdSql.query("select round(dataint) from jsons1 where jtag->'tag1'>1")
         tdSql.checkRows(3)
 
+        #test TD-12077
+        tdSql.execute("insert into jsons1_16 using jsons1 tags('{\"tag1\":\"收到货\",\"tag2\":\"\",\"tag3\":-2.111}') values(1591062628000, 2, NULL, '你就会', 'dws')")
+        tdSql.query("select jtag->'tag3' from jsons1_16")
+        tdSql.checkData(0, 0, '-2.111000000')
+
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)