Fix ifnull/nvl expr result wrong precision

src/sql/engine/expr/ob_expr_ifnull.cpp

@@ -80,9 +80,15 @@ int ObExprIfNull::calc_result_type2(ObExprResType &type,
     } else {
       type.set_scale(-1);
     }
-    if (lib::is_mysql_mode() && ob_is_real_type(type.get_type()) &&
+    if (lib::is_mysql_mode() && SCALE_UNKNOWN_YET != type.get_scale()) {
-         SCALE_UNKNOWN_YET != type.get_scale()) {
+      if (ob_is_real_type(type.get_type())) {
-      type.set_precision(static_cast<ObPrecision>(ObMySQLUtil::float_length(type.get_scale())));
+        type.set_precision(static_cast<ObPrecision>(ObMySQLUtil::float_length(type.get_scale())));
+      } else if (ob_is_number_tc(type.get_type())) { // TODO:@zuojiao.hzj add decimal_int here
+        const int16_t intd1 = type1.get_precision() - type1.get_scale();
+        const int16_t intd2 = type2.get_precision() - type2.get_scale();
+        const int16_t prec = MAX(type.get_precision(), MAX(intd1, intd2) + type.get_scale());
+        type.set_precision(static_cast<ObPrecision>(prec));
+      }
     }
     type.set_length(MAX(type1.get_length(), type2.get_length()));
     type1.set_calc_meta(type.get_obj_meta());

src/sql/engine/expr/ob_expr_nvl.cpp

@@ -112,6 +112,16 @@ int ObExprNvl::calc_result_type2(ObExprResType &type,
     } else {
       type.set_scale(-1);
     }
+    if (lib::is_mysql_mode() && SCALE_UNKNOWN_YET != type.get_scale()) {
+      if (ob_is_real_type(type.get_type())) {
+        type.set_precision(static_cast<ObPrecision>(ObMySQLUtil::float_length(type.get_scale())));
+      } else if (ob_is_number_tc(type.get_type())) { // TODO:@zuojiao.hzj add decimal_int here
+        const int16_t intd1 = type1.get_precision() - type1.get_scale();
+        const int16_t intd2 = type2.get_precision() - type2.get_scale();
+        const int16_t prec = MAX(type.get_precision(), MAX(intd1, intd2) + type.get_scale());
+        type.set_precision(static_cast<ObPrecision>(prec));
+      }
+    }
     type.set_length(MAX(type1.get_length(), type2.get_length()));
     //对于 int 和uint64的混合类型，需要提升类型至decimal
     if (lib::is_mysql_mode()

tools/deploy/mysql_test/test_suite/meta_info/r/mysql/meta_func.result

@@ -87,7 +87,7 @@ INSERT INTO t2 VALUES (0.0), (9.0);
 SELECT IFNULL(t2.EMPNUM,t1.EMPNUM) AS CEMPNUM
 FROM t1 LEFT JOIN t2 ON t1.EMPNUM=t2.EMPNUM;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def					CEMPNUM	246	6	4	Y	32768	2	63
+def					CEMPNUM	246	15	4	Y	32768	2	63
 CEMPNUM
 0.00
 2.00
@@ -100,7 +100,7 @@ ifnull(0, 0.0)
 insert into t3 values(0, 2.4, "123");
 select ifnull(a, b), ifnull(a, c) from t3;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
-def					ifnull(a, b)	246	11	1	Y	32768	0	63
+def					ifnull(a, b)	246	12	1	Y	32768	0	63
 def					ifnull(a, c)	253	44	1	Y	0	0	45
 ifnull(a, b)	ifnull(a, c)
 0	0

tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_nvl.result

@@ -731,7 +731,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c1, DECIMAL(10, 0)), t1.c17)]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c1, DECIMAL(11, 0)), t1.c17)]), filter(nil), rowset=256
       access([t1.c1], [t1.c17]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -772,7 +772,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c1, DECIMAL(10, 0)), cast(t1.c18, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c1, DECIMAL(11, 0)), cast(t1.c18, DECIMAL(11, 0)))]), filter(nil), rowset=256
       access([t1.c1], [t1.c18]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -7947,7 +7947,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c9, DECIMAL(10, 0)), t1.c17)]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c9, DECIMAL(11, 0)), t1.c17)]), filter(nil), rowset=256
       access([t1.c9], [t1.c17]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -7988,7 +7988,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c9, DECIMAL(10, 0)), cast(t1.c18, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c9, DECIMAL(11, 0)), cast(t1.c18, DECIMAL(11, 0)))]), filter(nil), rowset=256
       access([t1.c9], [t1.c18]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -9751,7 +9751,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c11, DECIMAL(10, 0)), t1.c17)]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c11, DECIMAL(20, 0)), t1.c17)]), filter(nil), rowset=256
       access([t1.c11], [t1.c17]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -9792,7 +9792,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c11, DECIMAL(10, 0)), cast(t1.c18, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c11, DECIMAL(20, 0)), cast(t1.c18, DECIMAL(20, 0)))]), filter(nil), rowset=256
       access([t1.c11], [t1.c18]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -10653,7 +10653,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c12, DECIMAL(10, 0)), t1.c17)]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c12, DECIMAL(20, 0)), t1.c17)]), filter(nil), rowset=256
       access([t1.c12], [t1.c17]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -10694,7 +10694,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c12, DECIMAL(10, 0)), cast(t1.c18, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c12, DECIMAL(20, 0)), cast(t1.c18, DECIMAL(20, 0)))]), filter(nil), rowset=256
       access([t1.c12], [t1.c18]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -14507,7 +14507,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(t1.c17, cast(t1.c1, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(t1.c17, cast(t1.c1, DECIMAL(11, 0)))]), filter(nil), rowset=256
       access([t1.c17], [t1.c1]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -14835,7 +14835,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(t1.c17, cast(t1.c9, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(t1.c17, cast(t1.c9, DECIMAL(11, 0)))]), filter(nil), rowset=256
       access([t1.c17], [t1.c9]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -14917,7 +14917,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(t1.c17, cast(t1.c11, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(t1.c17, cast(t1.c11, DECIMAL(20, 0)))]), filter(nil), rowset=256
       access([t1.c17], [t1.c11]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -14958,7 +14958,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(t1.c17, cast(t1.c12, DECIMAL(10, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(t1.c17, cast(t1.c12, DECIMAL(20, 0)))]), filter(nil), rowset=256
       access([t1.c17], [t1.c12]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15491,7 +15491,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(4, 0)), cast(t1.c3, DECIMAL(4, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c3, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c3]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15532,7 +15532,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(3, 0)), cast(t1.c4, DECIMAL(3, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c4, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c4]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15573,7 +15573,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(6, 0)), cast(t1.c5, DECIMAL(6, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c5, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c5]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15614,7 +15614,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(5, 0)), cast(t1.c6, DECIMAL(5, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c6, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c6]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15655,7 +15655,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(9, 0)), cast(t1.c7, DECIMAL(9, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c7, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c7]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -15696,7 +15696,7 @@ Query Plan
 ===============================================
 Outputs & filters:
 -------------------------------------
-  0 - output([nvl(cast(t1.c18, DECIMAL(8, 0)), cast(t1.c8, DECIMAL(8, 0)))]), filter(nil), rowset=256
+  0 - output([nvl(cast(t1.c18, DECIMAL(10, 0)), cast(t1.c8, DECIMAL(10, 0)))]), filter(nil), rowset=256
       access([t1.c18], [t1.c8]), partitions(p0)
       is_index_back=false, is_global_index=false,
       range_key([t1.__pk_increment]), range(MIN ; MAX)always true
@@ -19933,3 +19933,19 @@ select nvl(null,b) from t1;
 | 2020-09-13 20:26:40.000 |
 +-------------------------+
 drop table t1;
+
+#bug:
+create table t1 as select nvl(cast(1 as decimal(10, 7)), cast(2 as decimal(12, 5))) as c from dual;
+desc t1;
++-------+---------------+------+-----+---------+-------+
+| Field | Type          | Null | Key | Default | Extra |
++-------+---------------+------+-----+---------+-------+
+| c     | decimal(14,7) | NO   |     | NULL    |       |
++-------+---------------+------+-----+---------+-------+
+select * from t1;
++-----------+
+| c         |
++-----------+
+| 1.0000000 |
++-----------+
+drop table t1;

tools/deploy/mysql_test/test_suite/static_engine/t/expr_nvl.test

@@ -84,3 +84,9 @@ insert into t1 values(1, now());
 insert into t1 values(2, now(6));
 select nvl(null,b) from t1;
 drop table t1;
+
+--echo #bug:
+create table t1 as select nvl(cast(1 as decimal(10, 7)), cast(2 as decimal(12, 5))) as c from dual;
+desc t1;
+select * from t1;
+drop table t1;