Add Day_Of_Week Function As An Alias Of DayOfWeek

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

@@ -326,8 +326,9 @@ public static FunctionExpression dayofmonth(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.DAYOFMONTH, expressions);
   }
 
-  public static FunctionExpression dayofweek(Expression... expressions) {
-    return compile(FunctionProperties.None, BuiltinFunctionName.DAYOFWEEK, expressions);
+  public static FunctionExpression dayofweek(
+      FunctionProperties functionProperties, Expression... expressions) {
+    return compile(functionProperties, BuiltinFunctionName.DAYOFWEEK, expressions);
   }
 
   public static FunctionExpression dayofyear(Expression... expressions) {
@@ -338,6 +339,11 @@ public static FunctionExpression day_of_year(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.DAY_OF_YEAR, expressions);
   }
 
+  public static FunctionExpression day_of_week(
+      FunctionProperties functionProperties, Expression... expressions) {
+    return compile(functionProperties, BuiltinFunctionName.DAY_OF_WEEK, expressions);
+  }
+
   public static FunctionExpression from_days(Expression... expressions) {
     return compile(FunctionProperties.None, BuiltinFunctionName.FROM_DAYS, expressions);
   }

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

@@ -20,6 +20,7 @@
 import static org.opensearch.sql.expression.function.FunctionDSL.impl;
 import static org.opensearch.sql.expression.function.FunctionDSL.implWithProperties;
 import static org.opensearch.sql.expression.function.FunctionDSL.nullMissingHandling;
+import static org.opensearch.sql.expression.function.FunctionDSL.nullMissingHandlingWithProperties;
 import static org.opensearch.sql.utils.DateTimeFormatters.DATE_FORMATTER_LONG_YEAR;
 import static org.opensearch.sql.utils.DateTimeFormatters.DATE_FORMATTER_SHORT_YEAR;
 import static org.opensearch.sql.utils.DateTimeFormatters.DATE_TIME_FORMATTER_LONG_YEAR;
@@ -101,7 +102,8 @@ public void register(BuiltinFunctionRepository repository) {
     repository.register(day());
     repository.register(dayName());
     repository.register(dayOfMonth());
-    repository.register(dayOfWeek());
+    repository.register(dayOfWeek(BuiltinFunctionName.DAYOFWEEK.getName()));
+    repository.register(dayOfWeek(BuiltinFunctionName.DAY_OF_WEEK.getName()));
     repository.register(dayOfYear(BuiltinFunctionName.DAYOFYEAR));
     repository.register(dayOfYear(BuiltinFunctionName.DAY_OF_YEAR));
     repository.register(from_days());
@@ -346,11 +348,14 @@ private DefaultFunctionResolver dayOfMonth() {
   }
 
   /**
-   * DAYOFWEEK(STRING/DATE/DATETIME/TIMESTAMP).
+   * DAYOFWEEK(STRING/DATE/DATETIME/TIME/TIMESTAMP).
    * return the weekday index for date (1 = Sunday, 2 = Monday, …, 7 = Saturday).
    */
-  private DefaultFunctionResolver dayOfWeek() {
-    return define(BuiltinFunctionName.DAYOFWEEK.getName(),
+  private DefaultFunctionResolver dayOfWeek(FunctionName name) {
+    return define(name,
+        implWithProperties(nullMissingHandlingWithProperties(
+            (functionProperties, arg) -> DateTimeFunction.dayOfWeekToday(
+                functionProperties.getQueryStartClock())), INTEGER, TIME),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfWeek), INTEGER, DATE),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfWeek), INTEGER, DATETIME),
         impl(nullMissingHandling(DateTimeFunction::exprDayOfWeek), INTEGER, TIMESTAMP),
@@ -615,6 +620,16 @@ private DefaultFunctionResolver date_format() {
     );
   }
 
+  /**
+   * Day of Week implementation for ExprValue when passing in an arguemt of type TIME.
+   *
+   * @param clock Current clock taken from function properties
+   * @return ExprValue.
+   */
+  private ExprValue dayOfWeekToday(Clock clock) {
+    return new ExprIntegerValue((formatNow(clock).getDayOfWeek().getValue() % 7) + 1);
+  }
+
   /**
    * ADDDATE function implementation for ExprValue.
    *
@@ -771,7 +786,7 @@ private ExprValue exprDayOfMonth(ExprValue date) {
   /**
    * Day of Week implementation for ExprValue.
    *
-   * @param date ExprValue of Date/String type.
+   * @param date ExprValue of Date/Datetime/String/Timstamp type.
    * @return ExprValue.
    */
   private ExprValue exprDayOfWeek(ExprValue date) {

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

@@ -69,6 +69,7 @@ public enum BuiltinFunctionName {
   DAYOFMONTH(FunctionName.of("dayofmonth")),
   DAYOFWEEK(FunctionName.of("dayofweek")),
   DAYOFYEAR(FunctionName.of("dayofyear")),
+  DAY_OF_WEEK(FunctionName.of("day_of_week")),
   DAY_OF_YEAR(FunctionName.of("day_of_year")),
   FROM_DAYS(FunctionName.of("from_days")),
   FROM_UNIXTIME(FunctionName.of("from_unixtime")),

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

@@ -430,32 +430,150 @@ public void dayOfMonth() {
     assertEquals(integerValue(8), eval(expression));
   }
 
+  private void dayOfWeekQuery(
+      FunctionExpression dateExpression,
+      int dayOfWeek,
+      String testExpr) {
+    assertEquals(INTEGER, dateExpression.type());
+    assertEquals(integerValue(dayOfWeek), eval(dateExpression));
+    assertEquals(testExpr, dateExpression.toString());
+  }
+
   @Test
   public void dayOfWeek() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+
+    FunctionExpression expression1 = DSL.dayofweek(
+        functionProperties,
+        DSL.literal(new ExprDateValue("2020-08-07")));
+    FunctionExpression expression2 = DSL.dayofweek(
+        functionProperties,
+        DSL.literal(new ExprDateValue("2020-08-09")));
+    FunctionExpression expression3 = DSL.dayofweek(
+        functionProperties,
+        DSL.literal("2020-08-09"));
+    FunctionExpression expression4 = DSL.dayofweek(
+        functionProperties,
+        DSL.literal("2020-08-09 01:02:03"));
+
+    assertAll(
+        () -> dayOfWeekQuery(expression1, 6, "dayofweek(DATE '2020-08-07')"),
+
+        () -> dayOfWeekQuery(expression2, 1, "dayofweek(DATE '2020-08-09')"),
+
+        () -> dayOfWeekQuery(expression3, 1, "dayofweek(\"2020-08-09\")"),
+
+        () -> dayOfWeekQuery(expression4, 1, "dayofweek(\"2020-08-09 01:02:03\")")
+    );
+  }
+
+  private void dayOfWeekWithUnderscoresQuery(
+      FunctionExpression dateExpression,
+      int dayOfWeek,
+      String testExpr) {
+    assertEquals(INTEGER, dateExpression.type());
+    assertEquals(integerValue(dayOfWeek), eval(dateExpression));
+    assertEquals(testExpr, dateExpression.toString());
+  }
+
+  @Test
+  public void dayOfWeekWithUnderscores() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+
+    FunctionExpression expression1 = DSL.day_of_week(
+        functionProperties,
+        DSL.literal(new ExprDateValue("2020-08-07")));
+    FunctionExpression expression2 = DSL.day_of_week(
+        functionProperties,
+        DSL.literal(new ExprDateValue("2020-08-09")));
+    FunctionExpression expression3 = DSL.day_of_week(
+        functionProperties,
+        DSL.literal("2020-08-09"));
+    FunctionExpression expression4 = DSL.day_of_week(
+        functionProperties,
+        DSL.literal("2020-08-09 01:02:03"));
+
+    assertAll(
+        () -> dayOfWeekWithUnderscoresQuery(expression1, 6, "day_of_week(DATE '2020-08-07')"),
+
+        () -> dayOfWeekWithUnderscoresQuery(expression2, 1, "day_of_week(DATE '2020-08-09')"),
+
+        () -> dayOfWeekWithUnderscoresQuery(expression3, 1, "day_of_week(\"2020-08-09\")"),
+
+        () -> dayOfWeekWithUnderscoresQuery(
+            expression4, 1, "day_of_week(\"2020-08-09 01:02:03\")")
+    );
+  }
+
+  @Test
+  public void testDayOfWeekWithTimeType() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+    FunctionExpression expression = DSL.day_of_week(
+        functionProperties, DSL.literal(new ExprTimeValue("12:23:34")));
+
+    assertAll(
+        () -> assertEquals(INTEGER, eval(expression).type()),
+        () -> assertEquals((
+            LocalDate.now(
+                functionProperties.getQueryStartClock()).getDayOfWeek().getValue() % 7) + 1,
+            eval(expression).integerValue()),
+        () -> assertEquals("day_of_week(TIME '12:23:34')", expression.toString())
+    );
+  }
+
+  private void testInvalidDayOfWeek(String date) {
+    FunctionExpression expression = DSL.day_of_week(
+        functionProperties, DSL.literal(new ExprDateValue(date)));
+    eval(expression);
+  }
+
+  @Test
+  public void dayOfWeekWithUnderscoresLeapYear() {
+    lenient().when(nullRef.valueOf(env)).thenReturn(nullValue());
+    lenient().when(missingRef.valueOf(env)).thenReturn(missingValue());
+
+    assertAll(
+        //Feb. 29 of a leap year
+        () -> dayOfWeekWithUnderscoresQuery(DSL.day_of_week(
+            functionProperties,
+            DSL.literal("2020-02-29")), 7, "day_of_week(\"2020-02-29\")"),
+        //day after Feb. 29 of a leap year
+        () -> dayOfWeekWithUnderscoresQuery(DSL.day_of_week(
+            functionProperties,
+            DSL.literal("2020-03-01")), 1, "day_of_week(\"2020-03-01\")"),
+        //Feb. 28 of a non-leap year
+        () -> dayOfWeekWithUnderscoresQuery(DSL.day_of_week(
+            functionProperties,
+            DSL.literal("2021-02-28")), 1, "day_of_week(\"2021-02-28\")"),
+        //Feb. 29 of a non-leap year
+        () -> assertThrows(
+            SemanticCheckException.class, () ->  testInvalidDayOfWeek("2021-02-29"))
+    );
+  }
+
+  @Test
+  public void dayOfWeekWithUnderscoresInvalidArgument() {
     when(nullRef.type()).thenReturn(DATE);
     when(missingRef.type()).thenReturn(DATE);
-    assertEquals(nullValue(), eval(DSL.dayofweek(nullRef)));
-    assertEquals(missingValue(), eval(DSL.dayofweek(missingRef)));
+    assertEquals(nullValue(), eval(DSL.day_of_week(functionProperties, nullRef)));
+    assertEquals(missingValue(), eval(DSL.day_of_week(functionProperties, missingRef)));
 
-    FunctionExpression expression = DSL.dayofweek(DSL.literal(new ExprDateValue("2020-08-07")));
-    assertEquals(INTEGER, expression.type());
-    assertEquals("dayofweek(DATE '2020-08-07')", expression.toString());
-    assertEquals(integerValue(6), eval(expression));
-
-    expression = DSL.dayofweek(DSL.literal(new ExprDateValue("2020-08-09")));
-    assertEquals(INTEGER, expression.type());
-    assertEquals("dayofweek(DATE '2020-08-09')", expression.toString());
-    assertEquals(integerValue(1), eval(expression));
+    assertAll(
+        //40th day of the month
+        () -> assertThrows(SemanticCheckException.class,
+            () ->  testInvalidDayOfWeek("2021-02-40")),
 
-    expression = DSL.dayofweek(DSL.literal("2020-08-09"));
-    assertEquals(INTEGER, expression.type());
-    assertEquals("dayofweek(\"2020-08-09\")", expression.toString());
-    assertEquals(integerValue(1), eval(expression));
+        //13th month of the year
+        () -> assertThrows(SemanticCheckException.class,
+            () ->  testInvalidDayOfWeek("2021-13-29")),
 
-    expression = DSL.dayofweek(DSL.literal("2020-08-09 01:02:03"));
-    assertEquals(INTEGER, expression.type());
-    assertEquals("dayofweek(\"2020-08-09 01:02:03\")", expression.toString());
-    assertEquals(integerValue(1), eval(expression));
+        //incorrect format
+        () -> assertThrows(SemanticCheckException.class,
+            () ->  testInvalidDayOfWeek("asdfasdf"))
+    );
   }
 
   @Test
@@ -481,7 +599,7 @@ public void dayOfYear() {
     assertEquals(integerValue(220), eval(expression));
   }
 
-  public void testDayOfYearWithUnderscores(String date, int dayOfYear) {
+  private void testDayOfYearWithUnderscores(String date, int dayOfYear) {
     FunctionExpression expression = DSL.day_of_year(DSL.literal(new ExprDateValue(date)));
     assertEquals(INTEGER, expression.type());
     assertEquals(integerValue(dayOfYear), eval(expression));
@@ -548,7 +666,7 @@ public void dayOfYearWithUnderscoresLeapYear() {
     );
   }
 
-  public void testInvalidDayOfYear(String date) {
+  private void testInvalidDayOfYear(String date) {
     FunctionExpression expression = DSL.day_of_year(DSL.literal(new ExprDateValue(date)));
     eval(expression);
   }
@@ -714,7 +832,7 @@ public void month() {
     assertEquals(integerValue(8), eval(expression));
   }
 
-  public void testInvalidDates(String date) throws SemanticCheckException {
+  private void testInvalidDates(String date) throws SemanticCheckException {
     FunctionExpression expression = DSL.month_of_year(DSL.literal(new ExprDateValue(date)));
     eval(expression);
   }

docs/user/dql/functions.rst

@@ -1434,20 +1434,21 @@ Description
 
 Usage: dayofweek(date) returns the weekday index for date (1 = Sunday, 2 = Monday, …, 7 = Saturday).
 
+The `day_of_week` function is also provided as an alias.
+
 Argument type: STRING/DATE/DATETIME/TIMESTAMP
 
 Return type: INTEGER
 
 Example::
 
-    os> SELECT DAYOFWEEK(DATE('2020-08-26'))
+    os> SELECT DAYOFWEEK('2020-08-26'), DAY_OF_WEEK('2020-08-26')
     fetched rows / total rows = 1/1
-    +---------------------------------+
-    | DAYOFWEEK(DATE('2020-08-26'))   |
-    |---------------------------------|
-    | 4                               |
-    +---------------------------------+
-
+    +---------------------------+-----------------------------+
+    | DAYOFWEEK('2020-08-26')   | DAY_OF_WEEK('2020-08-26')   |
+    |---------------------------+-----------------------------|
+    | 4                         | 4                           |
+    +---------------------------+-----------------------------+
 
 
 DAYOFYEAR

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

@@ -217,6 +217,49 @@ public void testDayOfWeek() throws IOException {
     verifyDataRows(result, rows(4));
   }
 
+  @Test
+  public void testDayOfWeekWithUnderscores() throws IOException {
+    JSONObject result = executeQuery("select day_of_week(date('2020-09-16'))");
+    verifySchema(result, schema("day_of_week(date('2020-09-16'))", null, "integer"));
+    verifyDataRows(result, rows(4));
+
+    result = executeQuery("select day_of_week('2020-09-16')");
+    verifySchema(result, schema("day_of_week('2020-09-16')", null, "integer"));
+    verifyDataRows(result, rows(4));
+  }
+
+  @Test
+  public void testDayOfWeekAliasesReturnTheSameResults() throws IOException {
+    JSONObject result1 = executeQuery("SELECT dayofweek(date('2022-11-22'))");
+    JSONObject result2 = executeQuery("SELECT day_of_week(date('2022-11-22'))");
+    verifyDataRows(result1, rows(3));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofweek(CAST(date0 AS date)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_week(CAST(date0 AS date)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofweek(datetime(CAST(time0 AS STRING))) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_week(datetime(CAST(time0 AS STRING))) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofweek(CAST(time0 AS STRING)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_week(CAST(time0 AS STRING)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+
+    result1 = executeQuery(String.format(
+        "SELECT dayofweek(CAST(datetime0 AS timestamp)) FROM %s", TEST_INDEX_CALCS));
+    result2 = executeQuery(String.format(
+        "SELECT day_of_week(CAST(datetime0 AS timestamp)) FROM %s", TEST_INDEX_CALCS));
+    result1.getJSONArray("datarows").similar(result2.getJSONArray("datarows"));
+  }
+
   @Test
   public void testDayOfYear() throws IOException {
     JSONObject result = executeQuery("select dayofyear(date('2020-09-16'))");

sql/src/main/antlr/OpenSearchSQLParser.g4

@@ -426,6 +426,7 @@ dateTimeFunctionName
     | DAYOFMONTH
     | DAYOFWEEK
     | DAYOFYEAR
+    | DAY_OF_WEEK
     | FROM_DAYS
     | FROM_UNIXTIME
     | HOUR

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_day_of_week_functions() {
+    assertNotNull(parser.parse("SELECT dayofweek('2022-11-18')"));
+    assertNotNull(parser.parse("SELECT day_of_week('2022-11-18')"));
+  }
+
   @Test
   public void can_parse_dayofyear_functions() {
     assertNotNull(parser.parse("SELECT dayofyear('2022-11-18')"));