[BUG] Cast int type to date type

fe/fe-core/src/main/java/org/apache/doris/catalog/Type.java

@@ -979,6 +979,10 @@ public static Type getCmpType(Type t1, Type t2) {
 
         PrimitiveType t1ResultType = t1.getResultType().getPrimitiveType();
         PrimitiveType t2ResultType = t2.getResultType().getPrimitiveType();
+        if (canCompareDate(t1.getPrimitiveType(), t2.getPrimitiveType())) {
+            return Type.DATETIME;
+        }
+
         // Following logical is compatible with MySQL.
         if ((t1ResultType == PrimitiveType.VARCHAR && t2ResultType == PrimitiveType.VARCHAR)) {
             return Type.VARCHAR; 
@@ -1007,6 +1011,22 @@ public static Type getCmpType(Type t1, Type t2) {
         return Type.DOUBLE;
     }
 
+    public static boolean canCompareDate(PrimitiveType t1, PrimitiveType t2) {
+        if (t1.isDateType()) {
+            if (t2.isDateType() || t2.isStringType() || t2.isIntegerType()) {
+                return true;
+            }
+            return false;
+        } else if (t2.isDateType()) {
+            if (t1.isStringType() || t1.isIntegerType()) {
+                return true;
+            }
+            return false;
+        } else {
+            return false;
+        }
+    }
+
     public Type getMaxResolutionType() {
         Preconditions.checkState(true, "must implemented");
         return null;

fe/fe-core/src/test/java/org/apache/doris/planner/QueryPlanTest.java

@@ -388,6 +388,19 @@ public static void beforeClass() throws Exception {
                 "\"driver\" = \"Oracle Driver\",\n" +
                 "\"odbc_type\" = \"mysql\"\n" +
                 ");");
+
+        createTable("create table test.tbl_int_date (" +
+                "`date` datetime NULL," +
+                "`day` date NULL," +
+                "`site_id` int(11) NULL )" +
+                " ENGINE=OLAP " +
+                "DUPLICATE KEY(`date`, `day`, `site_id`)" +
+                "DISTRIBUTED BY HASH(`site_id`) BUCKETS 10 " +
+                "PROPERTIES (\n" +
+                "\"replication_num\" = \"1\",\n" +
+                "\"in_memory\" = \"false\",\n" +
+                "\"storage_format\" = \"V2\"\n" +
+                ");");
     }
 
     @AfterClass
@@ -1318,7 +1331,6 @@ public void testAggregateSatisfyOlapTableDistribution() throws Exception {
         Assert.assertTrue(explainString.contains("AGGREGATE (update finalize)"));
     }
 
-    @Test
     public void testLeadAndLagFunction() throws Exception {
         connectContext.setDatabase("default_cluster:test");
 
@@ -1338,6 +1350,37 @@ public void testLeadAndLagFunction() throws Exception {
         explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, queryStr);
         Assert.assertTrue(explainString.contains("lag(`query_time`, 1, 2)"));
     }
+
+    @Test
+    public void testIntDateTime() throws Exception {
+        connectContext.setDatabase("default_cluster:test");
+        //valid date
+        String sql = "select day from tbl_int_date where day in ('2020-10-30')";
+        String explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `day` IN ('2020-10-30 00:00:00')"));
+        //valid date
+        sql = "select day from tbl_int_date where day in ('2020-10-30','2020-10-29')";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `day` IN ('2020-10-30 00:00:00', '2020-10-29 00:00:00')"));
+
+        //valid datetime
+        sql = "select day from tbl_int_date where date in ('2020-10-30 12:12:30')";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `date` IN ('2020-10-30 12:12:30')"));
+        //valid datetime
+        sql = "select day from tbl_int_date where date in ('2020-10-30')";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `date` IN ('2020-10-30 00:00:00')"));
+
+        //int date
+        sql = "select day from tbl_int_date where day in (20201030)";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `day` IN ('2020-10-30 00:00:00')"));
+        //int datetime
+        sql = "select day from tbl_int_date where date in (20201030)";
+        explainString = UtFrameUtils.getSQLPlanOrErrorMsg(connectContext, "EXPLAIN " + sql);
+        Assert.assertTrue(explainString.contains("PREDICATES: `date` IN ('2020-10-30 00:00:00')"));
+    }
 }