[feat] Support for FOR READ ONLY/FOR FETCH ONLY (#2325)

* [feat] Support for FOR READ ONLY/FOR FETCH ONLY

* [chore] Spotless

Author: ANeumann82

src/main/java/net/sf/jsqlparser/statement/select/ForMode.java

@@ -20,7 +20,10 @@ public enum ForMode {
 
     NO_KEY_UPDATE("NO KEY UPDATE"),
 
-    KEY_SHARE("KEY SHARE");
+    KEY_SHARE("KEY SHARE"),
+
+    // https://www.ibm.com/docs/en/db2-for-zos/13.0.0?topic=statement-read-only-clause
+    READ_ONLY("READ ONLY"), FETCH_ONLY("FETCH ONLY");
 
     private final String value;
 

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

@@ -4248,6 +4248,8 @@ PlainSelect PlainSelect() #PlainSelect:
             | <K_SHARE> { plainSelect.setForMode(ForMode.SHARE); }
             | (<K_NO> <K_KEY> <K_UPDATE> { plainSelect.setForMode(ForMode.NO_KEY_UPDATE); })
             | (<K_KEY> <K_SHARE> { plainSelect.setForMode(ForMode.KEY_SHARE); })
+            | (<K_READ> <K_ONLY> { plainSelect.setForMode(ForMode.READ_ONLY); })
+            | (<K_FETCH> <K_ONLY> { plainSelect.setForMode(ForMode.FETCH_ONLY); })
             )
         [ LOOKAHEAD(2) <K_OF> updateTable = Table() { plainSelect.setForUpdateTable(updateTable); } ]
         [ LOOKAHEAD(<K_WAIT>) wait = Wait() { plainSelect.setWait(wait); } ]

src/test/java/net/sf/jsqlparser/statement/select/DB2Test.java

@@ -12,6 +12,8 @@
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.test.TestUtils;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 public class DB2Test {
     @Test
@@ -20,4 +22,16 @@ void testDB2SpecialRegister() throws JSQLParserException {
                 "SELECT * FROM TABLE1 where COL_WITH_TIMESTAMP <= CURRENT TIMESTAMP - CURRENT TIMEZONE";
         TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
     }
+
+    @ParameterizedTest
+    @ValueSource(strings = {
+            "SELECT * FROM table WITH UR",
+            "SELECT * FROM table WITH UR FOR READ ONLY",
+            "SELECT * FROM table FOR READ ONLY",
+            "SELECT * FROM table FOR FETCH ONLY",
+            "SELECT * FROM table FETCH FIRST 100 ROWS ONLY FOR READ ONLY"
+    })
+    void testWithIsolationLevelAndReadOnlyModes(String sqlStr) throws JSQLParserException {
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+    }
 }