Support DuckDB 2.0 CONNECT and DISCONNECT statements

Adds CONNECT target [AS alias] and DISCONNECT [name], which route a
session's queries to a remote database. Oracle's CONNECT BY is
unaffected.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EqinwHBKuAtPEmtXr3b5P2

Author: hayssams

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

@@ -0,0 +1,69 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2026 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement;
+
+/**
+ * DuckDB's {@code CONNECT target [AS alias]}, which routes the session's queries to a remote
+ * database.
+ */
+public class ConnectStatement implements Statement {
+    private String target;
+    private String alias;
+
+    public ConnectStatement() {}
+
+    public ConnectStatement(String target) {
+        this.target = target;
+    }
+
+    public String getTarget() {
+        return target;
+    }
+
+    public void setTarget(String target) {
+        this.target = target;
+    }
+
+    public ConnectStatement withTarget(String target) {
+        setTarget(target);
+        return this;
+    }
+
+    public String getAlias() {
+        return alias;
+    }
+
+    public void setAlias(String alias) {
+        this.alias = alias;
+    }
+
+    public ConnectStatement withAlias(String alias) {
+        setAlias(alias);
+        return this;
+    }
+
+    public StringBuilder appendTo(StringBuilder builder) {
+        builder.append("CONNECT ").append(target);
+        if (alias != null) {
+            builder.append(" AS ").append(alias);
+        }
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
+
+    @Override
+    public <T, S> T accept(StatementVisitor<T> statementVisitor, S context) {
+        return statementVisitor.visit(this, context);
+    }
+}

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

@@ -0,0 +1,54 @@
+/*-
+ * #%L
+ * JSQLParser library
+ * %%
+ * Copyright (C) 2004 - 2026 JSQLParser
+ * %%
+ * Dual licensed under GNU LGPL 2.1 or Apache License 2.0
+ * #L%
+ */
+package net.sf.jsqlparser.statement;
+
+/**
+ * DuckDB's {@code DISCONNECT [name]}, the counterpart of {@link ConnectStatement}.
+ */
+public class DisconnectStatement implements Statement {
+    private String name;
+
+    public DisconnectStatement() {}
+
+    public DisconnectStatement(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public DisconnectStatement withName(String name) {
+        setName(name);
+        return this;
+    }
+
+    public StringBuilder appendTo(StringBuilder builder) {
+        builder.append("DISCONNECT");
+        if (name != null) {
+            builder.append(" ").append(name);
+        }
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
+
+    @Override
+    public <T, S> T accept(StatementVisitor<T> statementVisitor, S context) {
+        return statementVisitor.visit(this, context);
+    }
+}

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

@@ -549,6 +549,20 @@ public <S> Void visit(DetachStatement detachStatement, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(ConnectStatement connectStatement, S context) {
+        analysis.claimTopLevel();
+        analysis.certain(StmtFeature.MODIFIES_SESSION);
+        return null;
+    }
+
+    @Override
+    public <S> Void visit(DisconnectStatement disconnectStatement, S context) {
+        analysis.claimTopLevel();
+        analysis.certain(StmtFeature.MODIFIES_SESSION);
+        return null;
+    }
+
     @Override
     public <S> Void visit(PurgeStatement purgeStatement, S context) {
         analysis.claimTopLevel();

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

@@ -395,6 +395,18 @@ default void visit(DetachStatement detachStatement) {
         this.visit(detachStatement, null);
     }
 
+    <S> T visit(ConnectStatement connectStatement, S context);
+
+    default void visit(ConnectStatement connectStatement) {
+        this.visit(connectStatement, null);
+    }
+
+    <S> T visit(DisconnectStatement disconnectStatement, S context);
+
+    default void visit(DisconnectStatement disconnectStatement) {
+        this.visit(disconnectStatement, null);
+    }
+
     <S> T visit(PurgeStatement purgeStatement, S context);
 
     default void visit(PurgeStatement purgeStatement) {

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

@@ -638,6 +638,16 @@ public <S> T visit(DetachStatement detachStatement, S context) {
         return null;
     }
 
+    @Override
+    public <S> T visit(ConnectStatement connectStatement, S context) {
+        return null;
+    }
+
+    @Override
+    public <S> T visit(DisconnectStatement disconnectStatement, S context) {
+        return null;
+    }
+
     @Override
     public <S> T visit(PurgeStatement purgeStatement, S context) {
         return null;

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

@@ -213,6 +213,8 @@
 import net.sf.jsqlparser.statement.ExtensionStatement;
 import net.sf.jsqlparser.statement.AttachStatement;
 import net.sf.jsqlparser.statement.DetachStatement;
+import net.sf.jsqlparser.statement.ConnectStatement;
+import net.sf.jsqlparser.statement.DisconnectStatement;
 
 
 /**
@@ -2516,6 +2518,28 @@ public void visit(DetachStatement detachStatement) {
         StatementVisitor.super.visit(detachStatement);
     }
 
+    @Override
+    public <S> Void visit(ConnectStatement connectStatement, S context) {
+        // no tables involved in this statement
+        return null;
+    }
+
+    @Override
+    public void visit(ConnectStatement connectStatement) {
+        StatementVisitor.super.visit(connectStatement);
+    }
+
+    @Override
+    public <S> Void visit(DisconnectStatement disconnectStatement, S context) {
+        // no tables involved in this statement
+        return null;
+    }
+
+    @Override
+    public void visit(DisconnectStatement disconnectStatement) {
+        StatementVisitor.super.visit(disconnectStatement);
+    }
+
     @Override
     public <S> Void visit(PurgeStatement purgeStatement, S context) {
         if (purgeStatement.getPurgeObjectType() == PurgeObjectType.TABLE) {

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

@@ -101,6 +101,8 @@
 import net.sf.jsqlparser.statement.ExtensionStatement;
 import net.sf.jsqlparser.statement.AttachStatement;
 import net.sf.jsqlparser.statement.DetachStatement;
+import net.sf.jsqlparser.statement.ConnectStatement;
+import net.sf.jsqlparser.statement.DisconnectStatement;
 
 public class StatementDeParser extends AbstractDeParser<Statement>
         implements StatementVisitor<StringBuilder> {
@@ -584,6 +586,18 @@ public <S> StringBuilder visit(DetachStatement detachStatement, S context) {
         return builder;
     }
 
+    @Override
+    public <S> StringBuilder visit(ConnectStatement connectStatement, S context) {
+        connectStatement.appendTo(builder);
+        return builder;
+    }
+
+    @Override
+    public <S> StringBuilder visit(DisconnectStatement disconnectStatement, S context) {
+        disconnectStatement.appendTo(builder);
+        return builder;
+    }
+
     @Override
     public <S> StringBuilder visit(PurgeStatement purgeStatement, S context) {
         purgeStatement.appendTo(builder);

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

@@ -103,6 +103,8 @@
 import net.sf.jsqlparser.statement.ExtensionStatement;
 import net.sf.jsqlparser.statement.AttachStatement;
 import net.sf.jsqlparser.statement.DetachStatement;
+import net.sf.jsqlparser.statement.ConnectStatement;
+import net.sf.jsqlparser.statement.DisconnectStatement;
 
 /**
  * @author gitmotte
@@ -505,6 +507,18 @@ public <S> Void visit(DetachStatement detachStatement, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(ConnectStatement connectStatement, S context) {
+        // TODO: not yet implemented
+        return null;
+    }
+
+    @Override
+    public <S> Void visit(DisconnectStatement disconnectStatement, S context) {
+        // TODO: not yet implemented
+        return null;
+    }
+
     @Override
     public <S> Void visit(PurgeStatement purgeStatement, S context) {
         // TODO: not yet implemented
@@ -737,6 +751,14 @@ public void visit(DetachStatement detachStatement) {
         visit(detachStatement, null);
     }
 
+    public void visit(ConnectStatement connectStatement) {
+        visit(connectStatement, null);
+    }
+
+    public void visit(DisconnectStatement disconnectStatement) {
+        visit(disconnectStatement, null);
+    }
+
     public void visit(PurgeStatement purgeStatement) {
         visit(purgeStatement, null);
     }

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

@@ -2952,6 +2952,12 @@ Statement SingleStatement() :
             |
             LOOKAHEAD({ getToken(1).kind == K_DETACH }) stm = DetachStatement()
             |
+            LOOKAHEAD({ getToken(1).kind == K_CONNECT && getToken(2).kind != K_BY })
+            stm = ConnectStatement()
+            |
+            LOOKAHEAD({ getToken(1).kind == K_DISCONNECT && getToken(2).kind != K_SESSION })
+            stm = DisconnectStatement()
+            |
             stm = PurgeStatement()
             |
             stm = SessionStatement()
@@ -4353,6 +4359,43 @@ RenameTableStatement RenameTableStatement(): {
     }
 }
 
+/**
+ * DuckDB's CONNECT target [AS alias], routing the session to a remote database.
+ */
+ConnectStatement ConnectStatement() #ConnectStatement:
+{
+    ConnectStatement connectStatement = new ConnectStatement();
+    ObjectNames name;
+    Token token;
+}
+{
+    <K_CONNECT>
+    (
+        token=<S_CHAR_LITERAL> { connectStatement.setTarget(token.image); }
+        |
+        name=RelObjectNames() { connectStatement.setTarget(String.join(".", name.getNames())); }
+    )
+    [ <K_AS> name=RelObjectNames() { connectStatement.setAlias(String.join(".", name.getNames())); } ]
+    { return connectStatement; }
+}
+
+/**
+ * DuckDB's DISCONNECT [name].
+ */
+DisconnectStatement DisconnectStatement() #DisconnectStatement:
+{
+    DisconnectStatement disconnectStatement = new DisconnectStatement();
+    ObjectNames name;
+}
+{
+    <K_DISCONNECT>
+    [
+        LOOKAHEAD(2)
+        name=RelObjectNames() { disconnectStatement.setName(String.join(".", name.getNames())); }
+    ]
+    { return disconnectStatement; }
+}
+
 /**
  * DuckDB's ATTACH [DATABASE] [IF NOT EXISTS] path [AS alias] [(options)].
  */