feat: Support OFFSET for PostgreSQL (#71)

* refactor: remove excess condition

* feat: support offset for postgesql

* fix: remove offsetClauseLocation which broke tests

* fix: fix pipeline tests

* docs: actualise license annotations

src/parsing/parsers/postgresql/jison/select/limit_clause.jison

@@ -1,18 +1,13 @@
-// Licensed to Cloudera, Inc. under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  Cloudera, Inc. licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
+// Copyright 2023 YANDEX LLC
 //
-//     http://www.apache.org/licenses/LICENSE-2.0
+// Licensed under the Apache License, Version 2.0 (the "License")
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 //
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Unless required by applicable law or agreed to in writing, software distributed under
+// the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied. See the License for the specific language governing permissions
+// and limitations under the License.
 
 OptionalLimitClause
  :
@@ -21,7 +16,6 @@ OptionalLimitClause
 
 LimitClause
  : 'LIMIT' UnsignedNumericLiteral
- | 'LIMIT' 'VARIABLE_REFERENCE'
  ;
 
 LimitClause_EDIT

src/parsing/parsers/postgresql/jison/select/offset_clause.jison

@@ -0,0 +1,26 @@
+// Copyright 2023 YANDEX LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License")
+// You may not use this file except in compliance with the License.
+// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software distributed under
+// the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+// either express or implied. See the License for the specific language governing permissions
+// and limitations under the License.
+
+OptionalOffsetClause
+ :
+ | OffsetClause
+ ;
+
+OffsetClause
+ : 'OFFSET' ValueExpression
+ ;
+
+OffsetClause_EDIT
+ : 'OFFSET' 'CURSOR'
+   {
+     parser.suggestFunctions({ types: ['BIGINT'] });
+   }
+ ;

src/parsing/parsers/postgresql/jison/select/offset_clause.test.json

@@ -0,0 +1,42 @@
+[
+  {
+    "namePrefix": "should suggest OFFSET",
+    "beforeCursor": "SELECT * FROM testTable LIMIT 100 ",
+    "afterCursor": "",
+    "noErrors": true,
+    "containsKeywords": ["OFFSET"],
+    "expectedResult": {
+      "lowerCase": false
+    }
+  },
+  {
+    "namePrefix": "should not throw errors",
+    "beforeCursor": "SELECT * FROM testTable OFFSET 100;",
+    "afterCursor": "",
+    "noErrors": true,
+    "containsKeywords": ["SELECT"],
+    "expectedResult": {
+      "lowerCase": false
+    }
+  },
+  {
+    "namePrefix": "should not throw errors",
+    "beforeCursor": "SELECT * FROM testTable LIMIT 1 OFFSET 12; ",
+    "afterCursor": "",
+    "noErrors": true,
+    "containsKeywords": ["SELECT"],
+    "expectedResult": {
+      "lowerCase": false
+    }
+  },
+  {
+    "namePrefix": "should not throw errors",
+    "beforeCursor": "SELECT * FROM testTable LIMIT 1; ",
+    "afterCursor": "",
+    "noErrors": true,
+    "containsKeywords": ["SELECT"],
+    "expectedResult": {
+      "lowerCase": false
+    }
+  }
+]