Add Day_Of_Month Function As An Alias Of DayOfMonth

core/src/main/java/org/opensearch/sql/expression/DSL.java

@@ -334,6 +334,10 @@ public static FunctionExpression dayofyear(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.DAYOFYEAR, expressions);
   }
 
+  public static FunctionExpression day_of_month(Expression... expressions) {
+    return compile(FunctionProperties.None, BuiltinFunctionName.DAY_OF_MONTH, expressions);
+  }
+
   public static FunctionExpression day_of_year(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.DAY_OF_YEAR, expressions);
   }

core/src/main/java/org/opensearch/sql/expression/datetime/DateTimeFunction.java

@@ -57,7 +57,6 @@
 import org.opensearch.sql.data.model.ExprValue;
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.exception.ExpressionEvaluationException;
-import org.opensearch.sql.exception.SemanticCheckException;
 import org.opensearch.sql.expression.function.BuiltinFunctionName;
 import org.opensearch.sql.expression.function.BuiltinFunctionRepository;
 import org.opensearch.sql.expression.function.DefaultFunctionResolver;
@@ -100,7 +99,8 @@ public void register(BuiltinFunctionRepository repository) {
     repository.register(date_sub());
     repository.register(day());
     repository.register(dayName());
-    repository.register(dayOfMonth());
+    repository.register(dayOfMonth(BuiltinFunctionName.DAYOFMONTH));
+    repository.register(dayOfMonth(BuiltinFunctionName.DAY_OF_MONTH));
     repository.register(dayOfWeek());
     repository.register(dayOfYear(BuiltinFunctionName.DAYOFYEAR));
     repository.register(dayOfYear(BuiltinFunctionName.DAY_OF_YEAR));
@@ -336,8 +336,8 @@ private DefaultFunctionResolver dayName() {
   /**
    * DAYOFMONTH(STRING/DATE/DATETIME/TIMESTAMP). return the day of the month (1-31).
    */
-  private DefaultFunctionResolver dayOfMonth() {
-    return define(BuiltinFunctionName.DAYOFMONTH.getName(),
+  private DefaultFunctionResolver dayOfMonth(BuiltinFunctionName name) {
+    return define(name.getName(),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfMonth), INTEGER, DATE),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfMonth), INTEGER, DATETIME),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfMonth), INTEGER, TIMESTAMP),

core/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java

@@ -67,6 +67,7 @@ public enum BuiltinFunctionName {
   DAY(FunctionName.of("day")),
   DAYNAME(FunctionName.of("dayname")),
   DAYOFMONTH(FunctionName.of("dayofmonth")),
+  DAY_OF_MONTH(FunctionName.of("day_of_month")),
   DAYOFWEEK(FunctionName.of("dayofweek")),
   DAYOFYEAR(FunctionName.of("dayofyear")),
   DAY_OF_YEAR(FunctionName.of("day_of_year")),

core/src/test/java/org/opensearch/sql/expression/datetime/DateTimeFunctionTest.java

@@ -430,6 +430,64 @@ public void dayOfMonth() {
     assertEquals(integerValue(8), eval(expression));
   }
 
+  private void testDayOfMonthWithUnderscores(FunctionExpression dateExpression, int dayOfMonth) {
+    assertEquals(INTEGER, dateExpression.type());
+    assertEquals(integerValue(dayOfMonth), eval(dateExpression));
+  }
+
+  @Test
+  public void dayOfMonthWithUnderscores() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+
+
+    FunctionExpression expression1 = DSL.dayofmonth(DSL.literal(new ExprDateValue("2020-08-07")));
+    FunctionExpression expression2 = DSL.dayofmonth(DSL.literal("2020-07-08"));
+
+    assertAll(
+        () -> testDayOfMonthWithUnderscores(expression1, 7),
+        () -> assertEquals("dayofmonth(DATE '2020-08-07')", expression1.toString()),
+
+        () -> testDayOfMonthWithUnderscores(expression2, 8),
+        () -> assertEquals("dayofmonth(\"2020-07-08\")", expression2.toString())
+
+    );
+  }
+
+  private void testInvalidDayOfMonth(String date) {
+    FunctionExpression expression = DSL.day_of_month(DSL.literal(new ExprDateValue(date)));
+    eval(expression);
+  }
+
+  @Test
+  public void dayOfMonthWithUnderscoresLeapYear() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+
+    //Feb. 29 of a leap year
+    testDayOfMonthWithUnderscores(DSL.day_of_month(DSL.literal("2020-02-29")), 29);
+
+    //Feb. 29 of a non-leap year
+    assertThrows(SemanticCheckException.class, () -> testInvalidDayOfMonth("2021-02-29"));
+  }
+
+  @Test
+  public void dayOfMonthWithUnderscoresInvalidArguments() {
+    lenient().when(nullRef.type()).thenReturn(DATE);
+    lenient().when(missingRef.type()).thenReturn(DATE);
+    assertEquals(nullValue(), eval(DSL.day_of_month(nullRef)));
+    assertEquals(missingValue(), eval(DSL.day_of_month(missingRef)));
+
+    //40th day of the month
+    assertThrows(SemanticCheckException.class, () -> testInvalidDayOfMonth("2021-02-40"));
+
+    //13th month of the year
+    assertThrows(SemanticCheckException.class, () -> testInvalidDayOfMonth("2021-13-40"));
+
+    //incorrect format
+    assertThrows(SemanticCheckException.class, () -> testInvalidDayOfMonth("asdfasdfasdf"));
+  }
+
   @Test
   public void dayOfWeek() {
     when(nullRef.type()).thenReturn(DATE);

docs/user/dql/functions.rst

@@ -1359,13 +1359,13 @@ DAY
 Description
 >>>>>>>>>>>
 
-Usage: day(date) extracts the day of the month for date, in the range 1 to 31. The dates with value 0 such as '0000-00-00' or '2008-00-00' are invalid.
+Usage: day(date) extracts the day of the month for date, in the range 1 to 31.
 
 Argument type: STRING/DATE/DATETIME/TIMESTAMP
 
 Return type: INTEGER
 
-Synonyms: DAYOFMONTH
+Synonyms: `DAYOFMONTH`_, `DAY_OF_MONTH`_
 
 Example::
 
@@ -1407,13 +1407,13 @@ DAYOFMONTH
 Description
 >>>>>>>>>>>
 
-Usage: dayofmonth(date) extracts the day of the month for date, in the range 1 to 31. The dates with value 0 such as '0000-00-00' or '2008-00-00' are invalid.
+Usage: dayofmonth(date) extracts the day of the month for date, in the range 1 to 31.
 
 Argument type: STRING/DATE/DATETIME/TIMESTAMP
 
 Return type: INTEGER
 
-Synonyms: DAY
+Synonyms: `DAY`_, `DAY_OF_MONTH`_
 
 Example::
 
@@ -1425,6 +1425,29 @@ Example::
     | 26                               |
     +----------------------------------+
 
+DAY_OF_MONTH
+----------
+
+Description
+>>>>>>>>>>>
+
+Usage: day_of_month(date) extracts the day of the month for date, in the range 1 to 31.
+
+Argument type: STRING/DATE/DATETIME/TIMESTAMP
+
+Return type: INTEGER
+
+Synonyms: `DAY`_, `DAYOFMONTH`_
+
+Example::
+
+    os> SELECT DAY_OF_MONTH('2020-08-26')
+    fetched rows / total rows = 1/1
+    +------------------------------+
+    | DAY_OF_MONTH('2020-08-26')   |
+    |------------------------------|
+    | 26                           |
+    +------------------------------+
 
 DAYOFWEEK
 ---------

integ-test/src/test/java/org/opensearch/sql/sql/DateTimeFunctionIT.java

@@ -206,6 +206,48 @@ public void testDayOfMonth() throws IOException {
     verifyDataRows(result, rows(16));
   }
 
+  @Test
+  public void testDayOfMonthWithUnderscores() throws IOException {
+    JSONObject result = executeQuery("select day_of_month(date('2020-09-16'))");
+    verifySchema(result, schema("day_of_month(date('2020-09-16'))", null, "integer"));
+    verifyDataRows(result, rows(16));
+
+    result = executeQuery("select day_of_month('2020-09-16')");
+    verifySchema(result, schema("day_of_month('2020-09-16')", null, "integer"));
+    verifyDataRows(result, rows(16));
+  }
+
+  @Test
+  public void testDayOfMonthAliasesReturnTheSameResults() throws IOException {
+    JSONObject result1 = executeQuery("SELECT dayofmonth(date('2022-11-22'))");
+    JSONObject result2 = executeQuery("SELECT day_of_month(date('2022-11-22'))");
+    verifyDataRows(result1, rows(22));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofmonth(CAST(date0 AS date)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_month(CAST(date0 AS date)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofmonth(datetime(CAST(time0 AS STRING))) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_month(datetime(CAST(time0 AS STRING))) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofmonth(CAST(time0 AS STRING)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_month(CAST(time0 AS STRING)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofmonth(CAST(datetime0 AS timestamp)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_month(CAST(datetime0 AS timestamp)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+  }
   @Test
   public void testDayOfWeek() throws IOException {
     JSONObject result = executeQuery("select dayofweek(date('2020-09-16'))");

sql/src/main/antlr/OpenSearchSQLParser.g4

@@ -426,6 +426,7 @@ dateTimeFunctionName
     | DAY
     | DAYNAME
     | DAYOFMONTH
+    | DAY_OF_MONTH
     | DAYOFWEEK
     | DAYOFYEAR
     | FROM_DAYS

sql/src/test/java/org/opensearch/sql/sql/antlr/SQLSyntaxParserTest.java

@@ -197,6 +197,12 @@ public void can_parse_week_of_year_functions() {
     assertNotNull(parser.parse("SELECT week_of_year('2022-11-18')"));
   }
 
+  @Test
+  public void can_parse_dayofmonth_functions() {
+    assertNotNull(parser.parse("SELECT dayofmonth('2022-11-18')"));
+    assertNotNull(parser.parse("SELECT day_of_month('2022-11-18')"));
+  }
+
   @Test
   public void can_parse_dayofyear_functions() {
     assertNotNull(parser.parse("SELECT dayofyear('2022-11-18')"));