Merge pull request #15855 from hexiaoting/dev_fetch

Add Support for OFFSET_FETCH_CLAUSE

src/Common/ErrorCodes.cpp

@@ -507,6 +507,8 @@ namespace ErrorCodes
     extern const int CANNOT_CREATE_RABBITMQ_QUEUE_BINDING = 541;
     extern const int CANNOT_REMOVE_RABBITMQ_EXCHANGE = 542;
     extern const int UNKNOWN_MYSQL_DATATYPES_SUPPORT_LEVEL = 543;
+    extern const int ROW_AND_ROWS_TOGETHER = 544;
+    extern const int FIRST_AND_NEXT_TOGETHER = 545;
 
     extern const int KEEPER_EXCEPTION = 999;
     extern const int POCO_EXCEPTION = 1000;

src/Parsers/ParserSelectQuery.cpp

@@ -19,6 +19,8 @@ namespace ErrorCodes
     extern const int TOP_AND_LIMIT_TOGETHER;
     extern const int WITH_TIES_WITHOUT_ORDER_BY;
     extern const int LIMIT_BY_WITH_TIES_IS_NOT_SUPPORTED;
+    extern const int ROW_AND_ROWS_TOGETHER;
+    extern const int FIRST_AND_NEXT_TOGETHER;
 }
 
 
@@ -45,6 +47,12 @@ bool ParserSelectQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserKeyword s_top("TOP");
     ParserKeyword s_with_ties("WITH TIES");
     ParserKeyword s_offset("OFFSET");
+    ParserKeyword s_fetch("FETCH");
+    ParserKeyword s_only("ONLY");
+    ParserKeyword s_row("ROW");
+    ParserKeyword s_rows("ROWS");
+    ParserKeyword s_first("FIRST");
+    ParserKeyword s_next("NEXT");
 
     ParserNotEmptyExpressionList exp_list(false);
     ParserNotEmptyExpressionList exp_list_for_with_clause(false);
@@ -247,8 +255,61 @@ bool ParserSelectQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     }
     else if (s_offset.ignore(pos, expected))
     {
+        /// OFFSET offset_row_count {ROW | ROWS} FETCH {FIRST | NEXT} fetch_row_count {ROW | ROWS} {ONLY | WITH TIES}
+        bool offset_with_fetch_maybe = false;
+
         if (!exp_elem.parse(pos, limit_offset, expected))
             return false;
+
+        if (s_row.ignore(pos, expected))
+        {
+            if (s_rows.ignore(pos, expected))
+                throw Exception("Can not use ROW and ROWS together", ErrorCodes::ROW_AND_ROWS_TOGETHER);
+            offset_with_fetch_maybe = true;
+        }
+        else if (s_rows.ignore(pos, expected))
+        {
+            offset_with_fetch_maybe = true;
+        }
+
+        if (offset_with_fetch_maybe && s_fetch.ignore(pos, expected))
+        {
+            /// OFFSET FETCH clause must exists with "ORDER BY"
+            if (!order_expression_list)
+                return false;
+
+            if (s_first.ignore(pos, expected))
+            {
+                if (s_next.ignore(pos, expected))
+                    throw Exception("Can not use FIRST and NEXT together", ErrorCodes::FIRST_AND_NEXT_TOGETHER);
+            }
+            else if (!s_next.ignore(pos, expected))
+                return false;
+
+            if (!exp_elem.parse(pos, limit_length, expected))
+                return false;
+
+            if (s_row.ignore(pos, expected))
+            {
+                if (s_rows.ignore(pos, expected))
+                    throw Exception("Can not use ROW and ROWS together", ErrorCodes::ROW_AND_ROWS_TOGETHER);
+            }
+            else if (!s_rows.ignore(pos, expected))
+                return false;
+
+            if (s_with_ties.ignore(pos, expected))
+            {
+                select_query->limit_with_ties = true;
+            }
+            else if (s_only.ignore(pos, expected))
+            {
+                select_query->limit_with_ties = false;
+            }
+            else
+            {
+                return false;
+            }
+        }
     }
 
     /// Because TOP n in totally equals LIMIT n

tests/queries/0_stateless/01525_select_with_offset_fetch_clause.reference

+7
+6
+5
+1	1
+2	1
+3	4
+1	1
+2	1
+3	4
+3	3

tests/queries/0_stateless/01525_select_with_offset_fetch_clause.sql

+SELECT number FROM numbers(10) ORDER BY number DESC OFFSET 2 ROWS FETCH NEXT 3 ROWS WITH TIES;
+
+DROP TABLE IF EXISTS test_fetch;
+CREATE TABLE test_fetch(a Int32, b Int32) Engine = Memory;
+INSERT INTO test_fetch VALUES(1, 1), (2, 1), (3, 4), (3, 3), (5, 4), (0, 6), (5, 7);
+SELECT * FROM test_fetch ORDER BY a OFFSET 1 ROW FETCH FIRST 3 ROWS ONLY;
+SELECT * FROM test_fetch ORDER BY a OFFSET 1 ROW FETCH FIRST 3 ROWS WITH TIES;
+DROP TABLE test_fetch;