Implement Oracle's Alter System

src/main/java/net/sf/jsqlparser/statement/StatementVisitor.java

@@ -11,6 +11,7 @@
 
 import net.sf.jsqlparser.statement.alter.Alter;
 import net.sf.jsqlparser.statement.alter.AlterSession;
+import net.sf.jsqlparser.statement.alter.AlterSystemStatement;
 import net.sf.jsqlparser.statement.alter.RenameTableStatement;
 import net.sf.jsqlparser.statement.alter.sequence.AlterSequence;
 import net.sf.jsqlparser.statement.comment.Comment;
@@ -116,4 +117,6 @@ public interface StatementVisitor {
     void visit(RenameTableStatement renameTableStatement);
 
     void visit(PurgeStatement purgeStatement);
+
+    void visit(AlterSystemStatement alterSystemStatement);
 }

src/main/java/net/sf/jsqlparser/statement/StatementVisitorAdapter.java

@@ -11,6 +11,7 @@
 
 import net.sf.jsqlparser.statement.alter.Alter;
 import net.sf.jsqlparser.statement.alter.AlterSession;
+import net.sf.jsqlparser.statement.alter.AlterSystemStatement;
 import net.sf.jsqlparser.statement.alter.RenameTableStatement;
 import net.sf.jsqlparser.statement.alter.sequence.AlterSequence;
 import net.sf.jsqlparser.statement.comment.Comment;
@@ -216,6 +217,11 @@ public void visit(AlterSession alterSession) {
     public void visit(RenameTableStatement renameTableStatement) {
     }
 
+    @Override
     public void visit(PurgeStatement purgeStatement) {
     }
+
+    @Override
+    public void visit(AlterSystemStatement alterSystemStatement) {
+    }
 }

src/main/java/net/sf/jsqlparser/statement/alter/AlterSystemOperation.java

@@ -0,0 +1,68 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2021 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+/*
+ * Copyright (C) 2021 JSQLParser.
+ *
+ * This library is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU Lesser General Public License as published by the Free Software Foundation; either version
+ * 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
+ * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with this library;
+ * if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+package net.sf.jsqlparser.statement.alter;
+
+/**
+ *
+ * @author <a href="mailto:andreas@manticore-projects.com">Andreas Reichel</a>
+ * @see  <a href="https://docs.oracle.com/cd/B12037_01/server.101/b10759/statements_2013.htm">ALTER SESSION</a>
+ */
+
+public enum AlterSystemOperation {
+    ARCHIVE_LOG("ARCHIVE LOG")
+    , CHECKPOINT("CHECKPOINT")
+    , CHECK_DATAFILES("CHECK DATAFILES")
+    , DUMP_ACTIVE_SESSION_HISTORY("DUMP ACTIVE SESSION HISTORY")
+    , ENABLE_DISTRIBUTED_RECOVERY("ENABLE DISTRIBUTED RECOVERY")
+    , DISABLE_DISTRIBUTED_RECOVERY("DISABLE DISTRIBUTED RECOVERY")
+    , ENABLE_RESTRICTED_SESSION("ENABLE RESTRICTED SESSION")
+    , DISABLE_RESTRICTED_SESSION("DISABLE RESTRICTED SESSION")
+    , FLUSH("FLUSH")
+    , DISCONNECT_SESSION("DISCONNECT SESSION")
+    , KILL_SESSION("KILL SESSION")
+    , SWITCH("SWITCH")
+    , SUSPEND("SUSPEND")
+    , RESUME("RESUME")
+    , QUIESCE("QUIESCE RESTRICTED")
+    , UNQUIESCE("UNQUIESCE")
+    , SHUTDOWN("SHUTDOWN")
+    , REGISTER("REGISTER")
+    , SET("SET")
+    , RESET("RESET");
+
+    private final String label;
+
+    AlterSystemOperation(String label) {
+        this.label = label;
+    }
+
+    @Override
+    public String toString() {
+        return label;
+    }
+
+
+}

src/main/java/net/sf/jsqlparser/statement/alter/AlterSystemStatement.java

@@ -0,0 +1,62 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2021 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement.alter;
+
+import java.util.List;
+import java.util.Objects;
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.StatementVisitor;
+
+/**
+ *
+ * @author <a href="mailto:andreas@manticore-projects.com">Andreas Reichel</a>
+ * @see  <a href="https://docs.oracle.com/cd/B12037_01/server.101/b10759/statements_2013.htm">ALTER SESSION</a>
+ */
+
+public class AlterSystemStatement implements Statement {
+    private final AlterSystemOperation operation;
+    private final List<String> parameters;
+
+    public AlterSystemStatement(AlterSystemOperation operation, List<String> parameters) {
+        this.operation = Objects.requireNonNull(operation, "The ALTER SYSTEM Operation must not be Null");
+        this.parameters = Objects.requireNonNull(parameters, "The PARAMETERS List must not be null although it can be empty.");
+    }
+
+    public AlterSystemOperation getOperation() {
+        return operation;
+    }
+
+    public List<String> getParameters() {
+        return parameters;
+    }
+
+    @Override
+    public void accept(StatementVisitor statementVisitor) {
+        statementVisitor.visit(this);
+      }
+
+    private static void appendParameters(StringBuilder builder, List<String> parameters) {
+        for (String s: parameters) {
+            builder.append(" ").append(s);
+        }
+    }
+
+    public StringBuilder appendTo(StringBuilder builder) {
+        builder.append("ALTER SYSTEM ").append(operation);
+        appendParameters(builder, parameters);
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
+
+}

src/main/java/net/sf/jsqlparser/util/TablesNamesFinder.java

@@ -69,6 +69,7 @@
 import net.sf.jsqlparser.statement.*;
 import net.sf.jsqlparser.statement.alter.Alter;
 import net.sf.jsqlparser.statement.alter.AlterSession;
+import net.sf.jsqlparser.statement.alter.AlterSystemStatement;
 import net.sf.jsqlparser.statement.alter.RenameTableStatement;
 import net.sf.jsqlparser.statement.alter.sequence.AlterSequence;
 import net.sf.jsqlparser.statement.comment.Comment;
@@ -1041,4 +1042,9 @@ public void visit(PurgeStatement purgeStatement) {
             ((Table) purgeStatement.getObject()).accept(this);
         }
     }
+
+    @Override
+    public void visit(AlterSystemStatement alterSystemStatement) {
+        // no tables involved in this statement
+    }
 }

src/main/java/net/sf/jsqlparser/util/deparser/StatementDeParser.java

@@ -31,6 +31,7 @@
 import net.sf.jsqlparser.statement.UseStatement;
 import net.sf.jsqlparser.statement.alter.Alter;
 import net.sf.jsqlparser.statement.alter.AlterSession;
+import net.sf.jsqlparser.statement.alter.AlterSystemStatement;
 import net.sf.jsqlparser.statement.alter.RenameTableStatement;
 import net.sf.jsqlparser.statement.alter.sequence.AlterSequence;
 import net.sf.jsqlparser.statement.comment.Comment;
@@ -361,4 +362,9 @@ public void visit(RenameTableStatement renameTableStatement) {
     public void visit(PurgeStatement purgeStatement) {
         purgeStatement.appendTo(buffer);
     }
+
+    @Override
+    public void visit(AlterSystemStatement alterSystemStatement) {
+        alterSystemStatement.appendTo(buffer);
+    }
 }

src/main/java/net/sf/jsqlparser/util/validation/validator/StatementValidator.java

@@ -29,6 +29,7 @@
 import net.sf.jsqlparser.statement.UseStatement;
 import net.sf.jsqlparser.statement.alter.Alter;
 import net.sf.jsqlparser.statement.alter.AlterSession;
+import net.sf.jsqlparser.statement.alter.AlterSystemStatement;
 import net.sf.jsqlparser.statement.alter.RenameTableStatement;
 import net.sf.jsqlparser.statement.alter.sequence.AlterSequence;
 import net.sf.jsqlparser.statement.comment.Comment;
@@ -289,4 +290,9 @@ public void visit(RenameTableStatement renameTableStatement) {
     public void visit(PurgeStatement purgeStatement) {
         //TODO: not yet implemented
     }
+
+    @Override
+    public void visit(AlterSystemStatement alterSystemStatement) {
+        //TODO: not yet implemented
+    }
 }