[CALCITE-6021] Add CURRENT_DATETIME function (enabled in BigQuery lib…

…rary)
apache · Oct 10, 2023 · a5f3926 · a5f3926
1 parent a67d089
commit a5f3926
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Showing 5 changed files with 63 additions and 24 deletions.
diff --git a/babel/src/test/resources/sql/big-query.iq b/babel/src/test/resources/sql/big-query.iq
@@ -148,23 +148,25 @@ SELECT current_date() AS the_date, t.current_date FROM t;
 #
 # Returns DATETIME
 
-!if (false) {
-SELECT CURRENT_DATETIME() as now;
-+----------------------------+
-| now                        |
-+----------------------------+
-| 2016-05-19T10:38:47.046465 |
-+----------------------------+
+SELECT CURRENT_DATETIME() > DATETIME '2008-12-25 15:30:00' as now;
++------+
+| now  |
++------+
+| true |
++------+
+(1 row)
+
 !ok
 
-SELECT CURRENT_DATETIME as now;
-+----------------------------+
-| now                        |
-+----------------------------+
-| 2016-05-19T10:38:47.046465 |
-+----------------------------+
+SELECT CURRENT_DATETIME > DATETIME '2008-12-25 15:30:00' as now;
++------+
+| now  |
++------+
+| true |
++------+
+(1 row)
+
 !ok
-!}
 
 # When a column named current_datetime is present, the column name and
 # the function call without parentheses are ambiguous. To ensure the
@@ -173,16 +175,26 @@ SELECT CURRENT_DATETIME as now;
 # select the function in the now column and the table column in the
 # current_datetime column.
 
-!if (false) {
 WITH t AS (SELECT 'column value' AS `current_datetime`)
-SELECT current_datetime() as now, t.current_datetime FROM t;
-+----------------------------+------------------+
-| now                        | current_datetime |
-+----------------------------+------------------+
-| 2016-05-19T10:38:47.046465 | column value     |
-+----------------------------+------------------+
+SELECT current_datetime() > DATETIME '2008-12-25 15:30:00' as now, t.current_datetime FROM t;
++------+------------------+
+| now  | current_datetime |
++------+------------------+
+| true | column value     |
++------+------------------+
+(1 row)
+
+!ok
+
+SELECT CURRENT_DATETIME('UTC') > DATETIME '2008-12-25 15:30:00';
++--------+
+| EXPR$0 |
++--------+
+| true   |
++--------+
+(1 row)
+
 !ok
-!}
 
 #####################################################################
 # CURRENT_TIME

diff --git a/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java b/core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java
@@ -162,6 +162,7 @@
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.COTH;
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.CSC;
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.CSCH;
+import static org.apache.calcite.sql.fun.SqlLibraryOperators.CURRENT_DATETIME;
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.DATE;
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.DATEADD;
 import static org.apache.calcite.sql.fun.SqlLibraryOperators.DATETIME;
@@ -996,6 +997,7 @@ Builder populate3() {
       map.put(CURRENT_TIME, systemFunctionImplementor);
       map.put(CURRENT_TIMESTAMP, systemFunctionImplementor);
       map.put(CURRENT_DATE, systemFunctionImplementor);
+      map.put(CURRENT_DATETIME, systemFunctionImplementor);
       map.put(LOCALTIME, systemFunctionImplementor);
       map.put(LOCALTIMESTAMP, systemFunctionImplementor);
 
@@ -3476,6 +3478,12 @@ private static class SystemFunctionImplementor
         return Expressions.call(BuiltInMethod.CURRENT_TIME.method, root);
       } else if (op == CURRENT_DATE) {
         return Expressions.call(BuiltInMethod.CURRENT_DATE.method, root);
+      } else if (op == CURRENT_DATETIME) {
+				if (call.getOperands().size() == 0) {
+	        return Expressions.call(BuiltInMethod.CURRENT_DATETIME.method, root);
+				} else {
+	        return Expressions.call(BuiltInMethod.CURRENT_DATETIME2.method, argValueList.get(0), root);
+				}
       } else if (op == LOCALTIMESTAMP) {
         return Expressions.call(BuiltInMethod.LOCAL_TIMESTAMP.method, root);
       } else if (op == LOCALTIME) {

diff --git a/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java b/core/src/main/java/org/apache/calcite/runtime/SqlFunctions.java
@@ -4653,7 +4653,22 @@ public static int currentDate(DataContext root) {
     return date;
   }
 
-  /** SQL {@code LOCAL_TIMESTAMP} function. */
+	/** SQL {@code CURRENT_DATETIME} function. */
+	@NonDeterministic
+	public static Long currentDatetime(DataContext root) {
+		final long timestamp = DataContext.Variable.CURRENT_TIMESTAMP.get(root);
+		return datetime(timestamp);
+	}
+
+	/** SQL {@code CURRENT_DATETIME} function with a specified timezone. */
+	@NonDeterministic
+	public static @Nullable Long currentDatetime(@Nullable String timezone, DataContext root) {
+		if (timezone == null) { return null; }
+		final long timestamp = DataContext.Variable.UTC_TIMESTAMP.get(root);
+		return datetime(timestamp, timezone);
+	}	
+
+	/** SQL {@code LOCAL_TIMESTAMP} function. */
   @NonDeterministic
   public static long localTimestamp(DataContext root) {
     return DataContext.Variable.LOCAL_TIMESTAMP.get(root);

diff --git a/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java b/core/src/main/java/org/apache/calcite/sql/fun/SqlLibraryOperators.java
@@ -795,7 +795,7 @@ static RelDataType deriveTypeSplit(SqlOperatorBinding operatorBinding,
   @LibraryOperator(libraries = {BIG_QUERY})
   public static final SqlFunction CURRENT_DATETIME =
       SqlBasicFunction.create("CURRENT_DATETIME",
-          ReturnTypes.TIMESTAMP.andThen(SqlTypeTransforms.TO_NULLABLE),
+          ReturnTypes.TIMESTAMP_NULLABLE,
           OperandTypes.NILADIC.or(OperandTypes.STRING),
           SqlFunctionCategory.TIMEDATE)
           .withSyntax(SqlSyntax.FUNCTION_ID);

diff --git a/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java b/core/src/main/java/org/apache/calcite/util/BuiltInMethod.java
@@ -682,6 +682,10 @@ public enum BuiltInMethod {
   CURRENT_TIMESTAMP(SqlFunctions.class, "currentTimestamp", DataContext.class),
   CURRENT_TIME(SqlFunctions.class, "currentTime", DataContext.class),
   CURRENT_DATE(SqlFunctions.class, "currentDate", DataContext.class),
+  CURRENT_DATETIME(SqlFunctions.class, "currentDatetime", DataContext.class),
+  CURRENT_DATETIME2(SqlFunctions.class, "currentDatetime", String.class, 
+  		DataContext.class),
+
   LOCAL_TIMESTAMP(SqlFunctions.class, "localTimestamp", DataContext.class),
   LOCAL_TIME(SqlFunctions.class, "localTime", DataContext.class),
   TIME_ZONE(SqlFunctions.class, "timeZone", DataContext.class),