fix(engine): MCOL-5778: if function fixed with handling temporal times and null values

datatypes/mcs_datatype.h

@@ -313,6 +313,18 @@ class SystemCatalog
       }
     }
 
+    bool isTemporal() const
+    {
+      switch (colDataType)
+      {
+        case datatypes::SystemCatalog::DATE:
+        case datatypes::SystemCatalog::DATETIME:
+        case datatypes::SystemCatalog::TIMESTAMP:
+        case datatypes::SystemCatalog::TIME: return true;
+        default: return false;
+      }
+    }
+
     bool isSignedInteger() const
     {
       switch (colDataType)

mysql-test/columnstore/basic/r/mcol-5963.result

@@ -0,0 +1,130 @@
+DROP DATABASE IF EXISTS mcol5963;
+CREATE DATABASE mcol5963;
+USE mcol5963;
+create table FOO(foo datetime) engine = columnstore;
+insert into FOO(foo) values ('2025-08-27 15:26:25');
+select if(0 = 1, '2025-08-27 15:26:25', foo) from FOO;
+if(0 = 1, '2025-08-27 15:26:25', foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, foo) from FOO;
+if(0 = 1, null, foo)
+2025-08-27 15:26:25
+select if(0 = 1, true, foo) from FOO;
+if(0 = 1, true, foo)
+2025-08-27 15:26:25
+select if(0 = 1, 5, foo) from FOO;
+if(0 = 1, 5, foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, "text");
+if(0 = 1, null, "text")
+text
+drop table FOO;
+create table FOO(foo datetime) engine = innodb;
+insert into FOO(foo) values ('2025-08-27 15:26:25');
+select if(0 = 1, '2025-08-27 15:26:25', foo) from FOO;
+if(0 = 1, '2025-08-27 15:26:25', foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, foo) from FOO;
+if(0 = 1, null, foo)
+2025-08-27 15:26:25
+select if(0 = 1, true, foo) from FOO;
+if(0 = 1, true, foo)
+2025-08-27 15:26:25
+select if(0 = 1, 5, foo) from FOO;
+if(0 = 1, 5, foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, "text");
+if(0 = 1, null, "text")
+text
+drop table FOO;
+create table FOO_DATE(foo date) engine = columnstore;
+insert into FOO_DATE(foo) values ('2025-08-27');
+select if(0 = 1, true, foo) from FOO_DATE;
+if(0 = 1, true, foo)
+2025-08-27
+select if(0 = 1, 5, foo) from FOO_DATE;
+if(0 = 1, 5, foo)
+2025-08-27
+select if(0 = 1, null, foo) from FOO_DATE;
+if(0 = 1, null, foo)
+2025-08-27
+drop table FOO_DATE;
+create table FOO_DATE(foo date) engine = innodb;
+insert into FOO_DATE(foo) values ('2025-08-27');
+select if(0 = 1, true, foo) from FOO_DATE;
+if(0 = 1, true, foo)
+2025-08-27
+select if(0 = 1, 5, foo) from FOO_DATE;
+if(0 = 1, 5, foo)
+2025-08-27
+select if(0 = 1, null, foo) from FOO_DATE;
+if(0 = 1, null, foo)
+2025-08-27
+drop table FOO_DATE;
+create table FOO_TIME(foo time) engine = columnstore;
+insert into FOO_TIME(foo) values ('15:26:25');
+select if(0 = 1, true, foo) from FOO_TIME;
+if(0 = 1, true, foo)
+15:26:25
+select if(0 = 1, 5, foo) from FOO_TIME;
+if(0 = 1, 5, foo)
+15:26:25
+select if(0 = 1, null, foo) from FOO_TIME;
+if(0 = 1, null, foo)
+15:26:25
+drop table FOO_TIME;
+create table FOO_TIME(foo time) engine = innodb;
+insert into FOO_TIME(foo) values ('15:26:25');
+select if(0 = 1, true, foo) from FOO_TIME;
+if(0 = 1, true, foo)
+15:26:25
+select if(0 = 1, 5, foo) from FOO_TIME;
+if(0 = 1, 5, foo)
+15:26:25
+select if(0 = 1, null, foo) from FOO_TIME;
+if(0 = 1, null, foo)
+15:26:25
+drop table FOO_TIME;
+create table FOO_TS(foo timestamp) engine = columnstore;
+insert into FOO_TS(foo) values ('2025-08-27 15:26:25');
+select if(0 = 1, true, foo) from FOO_TS;
+if(0 = 1, true, foo)
+2025-08-27 15:26:25
+select if(0 = 1, 5, foo) from FOO_TS;
+if(0 = 1, 5, foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, foo) from FOO_TS;
+if(0 = 1, null, foo)
+2025-08-27 15:26:25
+drop table FOO_TS;
+create table FOO_TS(foo timestamp) engine = innodb;
+insert into FOO_TS(foo) values ('2025-08-27 15:26:25');
+select if(0 = 1, true, foo) from FOO_TS;
+if(0 = 1, true, foo)
+2025-08-27 15:26:25
+select if(0 = 1, 5, foo) from FOO_TS;
+if(0 = 1, 5, foo)
+2025-08-27 15:26:25
+select if(0 = 1, null, foo) from FOO_TS;
+if(0 = 1, null, foo)
+2025-08-27 15:26:25
+drop table FOO_TS;
+create table FOO(foo varchar(30)) engine = columnstore;
+insert into FOO(foo) values ("text1");
+select if(0 = 1, true, foo) from FOO;
+if(0 = 1, true, foo)
+text1
+select if(0 = 1, NULL, foo) from FOO;
+if(0 = 1, NULL, foo)
+text1
+drop table FOO;
+create table FOO(foo int) engine = columnstore;
+insert into FOO(foo) values (123);
+select if(0 = 1, true, foo) from FOO;
+if(0 = 1, true, foo)
+123
+select if(0 = 1, NULL, foo) from FOO;
+if(0 = 1, NULL, foo)
+123
+drop table FOO;
+DROP DATABASE mcol5963;

mysql-test/columnstore/basic/t/mcol-5963.test

@@ -0,0 +1,110 @@
+-- source ../include/have_columnstore.inc
+-- source include/have_innodb.inc
+
+--disable_warnings
+DROP DATABASE IF EXISTS mcol5963;
+--enable_warnings
+
+CREATE DATABASE mcol5963;
+
+USE mcol5963;
+
+create table FOO(foo datetime) engine = columnstore;
+insert into FOO(foo) values ('2025-08-27 15:26:25');
+ 
+select if(0 = 1, '2025-08-27 15:26:25', foo) from FOO;
+select if(0 = 1, null, foo) from FOO;
+select if(0 = 1, true, foo) from FOO;
+select if(0 = 1, 5, foo) from FOO;
+select if(0 = 1, null, "text");
+
+drop table FOO;
+
+# InnoDB comparison for DATETIME
+create table FOO(foo datetime) engine = innodb;
+insert into FOO(foo) values ('2025-08-27 15:26:25');
+
+select if(0 = 1, '2025-08-27 15:26:25', foo) from FOO;
+select if(0 = 1, null, foo) from FOO;
+select if(0 = 1, true, foo) from FOO;
+select if(0 = 1, 5, foo) from FOO;
+select if(0 = 1, null, "text");
+
+drop table FOO;
+
+# Additional temporal types: DATE
+create table FOO_DATE(foo date) engine = columnstore;
+insert into FOO_DATE(foo) values ('2025-08-27');
+
+select if(0 = 1, true, foo) from FOO_DATE;
+select if(0 = 1, 5, foo) from FOO_DATE;
+select if(0 = 1, null, foo) from FOO_DATE;
+
+drop table FOO_DATE;
+
+# InnoDB comparison for DATE
+create table FOO_DATE(foo date) engine = innodb;
+insert into FOO_DATE(foo) values ('2025-08-27');
+
+select if(0 = 1, true, foo) from FOO_DATE;
+select if(0 = 1, 5, foo) from FOO_DATE;
+select if(0 = 1, null, foo) from FOO_DATE;
+
+drop table FOO_DATE;
+
+# Additional temporal types: TIME
+
+create table FOO_TIME(foo time) engine = columnstore;
+insert into FOO_TIME(foo) values ('15:26:25');
+
+select if(0 = 1, true, foo) from FOO_TIME;
+select if(0 = 1, 5, foo) from FOO_TIME;
+select if(0 = 1, null, foo) from FOO_TIME;
+drop table FOO_TIME;
+
+# InnoDB comparison for TIME
+create table FOO_TIME(foo time) engine = innodb;
+insert into FOO_TIME(foo) values ('15:26:25');
+
+select if(0 = 1, true, foo) from FOO_TIME;
+select if(0 = 1, 5, foo) from FOO_TIME;
+select if(0 = 1, null, foo) from FOO_TIME;
+
+drop table FOO_TIME;
+
+# Additional temporal types: TIMESTAMP
+create table FOO_TS(foo timestamp) engine = columnstore;
+
+insert into FOO_TS(foo) values ('2025-08-27 15:26:25');
+select if(0 = 1, true, foo) from FOO_TS;
+select if(0 = 1, 5, foo) from FOO_TS;
+select if(0 = 1, null, foo) from FOO_TS;
+
+drop table FOO_TS;
+
+# InnoDB comparison for TIMESTAMP
+create table FOO_TS(foo timestamp) engine = innodb;
+insert into FOO_TS(foo) values ('2025-08-27 15:26:25');
+
+select if(0 = 1, true, foo) from FOO_TS;
+select if(0 = 1, 5, foo) from FOO_TS;
+select if(0 = 1, null, foo) from FOO_TS;
+
+drop table FOO_TS;
+
+create table FOO(foo varchar(30)) engine = columnstore;
+insert into FOO(foo) values ("text1");
+
+select if(0 = 1, true, foo) from FOO;
+select if(0 = 1, NULL, foo) from FOO;
+
+drop table FOO;
+
+create table FOO(foo int) engine = columnstore;
+insert into FOO(foo) values (123);
+
+select if(0 = 1, true, foo) from FOO;
+select if(0 = 1, NULL, foo) from FOO;
+
+drop table FOO;
+DROP DATABASE mcol5963;

utils/funcexp/func_if.cpp

@@ -28,6 +28,7 @@ using namespace std;
 #include "functor_all.h"
 #include "functioncolumn.h"
 #include "predicateoperator.h"
+#include "constantcolumn.h"
 using namespace execplan;
 
 #include "rowgroup.h"
@@ -124,9 +125,58 @@ CalpontSystemCatalog::ColType Func_if::operationType(FunctionParm& fp,
     return ct;
   }
 
-  CalpontSystemCatalog::ColType ct = fp[1]->data()->resultType();
+  // Special handling: if one branch is a NULL constant and the other is a temporal type,
+  // the result type must be that temporal type. Otherwise PredicateOperator might promote
+  // to a non-temporal type causing zero-date conversions.
+  auto chooseTemporalIfOtherIsNull = [](const CalpontSystemCatalog::ColType& other,
+                                        bool maybeNullIsNullConst,
+                                        CalpontSystemCatalog::ColType& out) -> bool {
+    if (!maybeNullIsNullConst)
+      return false;
+    out = other;
+    return other.isTemporal();
+  };
+
+  bool isNullConst1 = false, isNullConst2 = false;
+  if (auto cc1 = dynamic_cast<execplan::ConstantColumn*>(fp[1]->data()))
+  {
+    isNullConst1 = cc1->isNull();
+  }
+  if (auto cc2 = dynamic_cast<execplan::ConstantColumn*>(fp[2]->data()))
+  {
+    isNullConst2 = cc2->isNull();
+  }
+
+  auto rt1 = fp[1]->data()->resultType();
+  auto rt2 = fp[2]->data()->resultType();
+
+  CalpontSystemCatalog::ColType chosen;
+  if (chooseTemporalIfOtherIsNull(rt2, isNullConst1, chosen))
+  {
+    resultType = chosen;
+    return chosen;
+  }
+  if (chooseTemporalIfOtherIsNull(rt1, isNullConst2, chosen))
+  {
+    resultType = chosen;
+    return chosen;
+  }
+
+  // If exactly one side is temporal and the other side is not string, prefer temporal type.
+  if (rt1.isTemporal() && !rt2.isTemporal() && !datatypes::isCharType(rt2.colDataType))
+  {
+    resultType = rt1;
+    return rt1;
+  }
+  if (rt2.isTemporal() && !rt1.isTemporal() && !datatypes::isCharType(rt1.colDataType))
+  {
+    resultType = rt2;
+    return rt2;
+  }
+
   PredicateOperator op;
-  op.setOpType(ct, fp[2]->data()->resultType());
+  op.setOpType(rt1, rt2);
+  CalpontSystemCatalog::ColType ct;
   ct = op.operationType();
   resultType = ct;
   return ct;