feat: Allow OUTER keyword as function parameter name (#2021)

* feat: Allow OUTER keyword as function parameter name

* chore: Spotless

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -4619,15 +4619,16 @@ JdbcNamedParameter JdbcNamedParameter() : {
 }
 
 OracleNamedFunctionParameter OracleNamedFunctionParameter() : {
- String name;
+ Token token = null;
+ String name = null;
  Expression expression;
 }
 {
- name=RelObjectNameExt2()
+ ( name=RelObjectNameExt2() | token=<K_OUTER> )
  <K_ORACLE_NAMED_PARAMETER_ASSIGNMENT>
  expression=Expression()
  {
- return new OracleNamedFunctionParameter(name, expression);
+ return new OracleNamedFunctionParameter(name != null ? name : token.image, expression);
  }
 }
 

src/test/java/net/sf/jsqlparser/statement/select/TableFunctionTest.java

@@ -31,4 +31,20 @@ void testLateralFlat() throws JSQLParserException {
  TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
  }
 
+ /**
+ * The SQL keyword "OUTER" is a valid parameter name for Snowflake's FLATTEN table function.
+ */
+ @Test
+ void testTableFunctionWithNamedParameterWhereNameIsOuterKeyword() throws JSQLParserException {
+ String sqlStr =
+ "INSERT INTO db.schema.target\n" +
+ " (Name, FriendParent)\n" +
+ " SELECT\n" +
+ " i.DATA_VALUE:Name AS Name,\n" +
+ " f1.Value:Parent:Name AS FriendParent\n" +
+ " FROM\n" +
+ " db.schema.source AS i,\n" +
+ " lateral flatten(input => i.DATA_VALUE:Friends, outer => true) AS f1;";
+ TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+ }
 }