Fix divide function with a UDF

Signed-off-by: Yuanchun Shen <yuanchu@amazon.com>

Author: yuancu

core/src/main/java/org/opensearch/sql/calcite/udf/mathUDF/DivideFunction.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.calcite.udf.mathUDF;
+
+import org.opensearch.sql.calcite.udf.UserDefinedFunction;
+
+public class DivideFunction implements UserDefinedFunction {
+
+  @Override
+  public Object eval(Object... args) {
+    double dividend = ((Number) args[0]).doubleValue();
+    double divisor = ((Number) args[1]).doubleValue();
+    return dividend / divisor;
+  }
+}

core/src/main/java/org/opensearch/sql/calcite/utils/BuiltinFunctionUtils.java

@@ -90,6 +90,7 @@
 import org.opensearch.sql.calcite.udf.datetimeUDF.YearWeekFunction;
 import org.opensearch.sql.calcite.udf.mathUDF.CRC32Function;
 import org.opensearch.sql.calcite.udf.mathUDF.ConvFunction;
+import org.opensearch.sql.calcite.udf.mathUDF.DivideFunction;
 import org.opensearch.sql.calcite.udf.mathUDF.EulerFunction;
 import org.opensearch.sql.calcite.udf.mathUDF.ModFunction;
 import org.opensearch.sql.calcite.udf.mathUDF.SqrtFunction;
@@ -138,7 +139,7 @@ static SqlOperator translate(String op) {
       case "*":
         return SqlStdOperatorTable.MULTIPLY;
       case "/":
-        return SqlStdOperatorTable.DIVIDE;
+        return TransferUserDefinedFunction(DivideFunction.class, "/", ReturnTypes.DOUBLE);
         // Built-in String Functions
       case "ASCII":
         return SqlStdOperatorTable.ASCII;

integ-test/src/test/java/org/opensearch/sql/calcite/standalone/CalcitePPLBuiltinFunctionIT.java

@@ -377,4 +377,14 @@ public void testSignAndRound() {
         actual, schema("name", "string"), schema("age", "integer"), schema("thirty_one", "double"));
     verifyDataRows(actual, rows("Hello", 30, 31));
   }
+
+  @Test
+  public void testDivide() {
+    JSONObject actual =
+        executeQuery(
+            String.format(
+                "source=%s | where name = 'Hello' | eval res1 = 22 / 7, res2 = age / 11 | fields res1", TEST_INDEX_STATE_COUNTRY));
+    verifySchema(actual, schema("res1", "double"));
+    verifyDataRows(actual, closeTo(3.142857142857143, 2.727272727272727));
+  }
 }