feat: parse PostgreSQL DROP FOREIGN DATA WRAPPER and DROP USER MAPPING

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

@@ -85,6 +85,7 @@
 import net.sf.jsqlparser.statement.delete.Delete;
 import net.sf.jsqlparser.statement.drop.Drop;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.execute.Execute;
 import net.sf.jsqlparser.statement.export.Export;
 import net.sf.jsqlparser.statement.export.ExportDataStatement;
@@ -1365,6 +1366,11 @@ public <S> Void visit(AlterUserMapping statement, S context) {
         return schemaOnly();
     }
 
+    @Override
+    public <S> Void visit(DropUserMapping statement, S context) {
+        return schemaOnly();
+    }
+
     @Override
     public <S> Void visit(CreateRule statement, S context) {
         return schemaOnly();

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

@@ -27,6 +27,7 @@
 import net.sf.jsqlparser.statement.alter.AlterTrigger;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
 import net.sf.jsqlparser.statement.alter.AlterStatistics;
 import net.sf.jsqlparser.statement.alter.AlterRelation;
@@ -945,6 +946,14 @@ default void visit(AlterUserMapping statement) {
         visit(statement, null);
     }
 
+    default <S> T visit(DropUserMapping statement, S context) {
+        return null;
+    }
+
+    default void visit(DropUserMapping statement) {
+        visit(statement, null);
+    }
+
     default <S> T visit(CreateAccessMethod statement, S context) {
         return null;
     }

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

@@ -15,6 +15,7 @@
 import net.sf.jsqlparser.statement.alter.AlterRoutine;
 import net.sf.jsqlparser.statement.alter.AlterTrigger;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
 import net.sf.jsqlparser.statement.create.fdw.CreateForeignDataWrapper;
 import net.sf.jsqlparser.statement.alter.AlterForeignDataWrapper;
@@ -1087,6 +1088,11 @@ public <S> T visit(AlterUserMapping statement, S context) {
         return visitForeignDataStatement(statement, context);
     }
 
+    @Override
+    public <S> T visit(DropUserMapping statement, S context) {
+        return null;
+    }
+
     @Override
     public <S> T visit(CreateRule statement, S context) {
         statement.visitTables(table -> table.accept(fromItemVisitor, context));

src/main/java/net/sf/jsqlparser/statement/drop/Drop.java

@@ -31,7 +31,7 @@
 public class Drop implements Statement {
 
     public enum ObjectType {
-        DATABASE, EVENT, FUNCTION, INDEX, PROCEDURE, SCHEMA, SEQUENCE, SERVER, TABLE, TABLESPACE, TRIGGER, VIEW, FOREIGN_TABLE, AGGREGATE, DOMAIN, EVENT_TRIGGER, GROUP, OWNED, ROLE, ROUTINE, RULE, TYPE, USER, SYNONYM, OTHER;
+        DATABASE, EVENT, FUNCTION, INDEX, PROCEDURE, SCHEMA, SEQUENCE, SERVER, TABLE, TABLESPACE, TRIGGER, VIEW, FOREIGN_TABLE, FOREIGN_DATA_WRAPPER, AGGREGATE, DOMAIN, EVENT_TRIGGER, GROUP, OWNED, ROLE, ROUTINE, RULE, TYPE, USER, SYNONYM, OTHER;
 
         /** Targets are {@link RoutineReference}s, each with an optional argument signature. */
         public boolean hasRoutineTargets() {

src/main/java/net/sf/jsqlparser/statement/drop/DropUserMapping.java

@@ -0,0 +1,66 @@
+/*-
+ * #%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.drop;
+
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.StatementVisitor;
+
+/**
+ * PostgreSQL {@code DROP USER MAPPING [IF EXISTS] FOR user SERVER server}. A user mapping has no
+ * name of its own, so it is identified by the user and the server, as in
+ * {@link net.sf.jsqlparser.statement.create.usermapping.CreateUserMapping}.
+ */
+public class DropUserMapping implements Statement {
+    private String user;
+    private String server;
+    private boolean ifExists;
+
+    public String getUser() {
+        return user;
+    }
+
+    public void setUser(String value) {
+        user = value;
+    }
+
+    public String getServer() {
+        return server;
+    }
+
+    public void setServer(String value) {
+        server = value;
+    }
+
+    public boolean isIfExists() {
+        return ifExists;
+    }
+
+    public void setIfExists(boolean value) {
+        ifExists = value;
+    }
+
+    public StringBuilder appendTo(StringBuilder sql) {
+        sql.append("DROP USER MAPPING ");
+        if (ifExists) {
+            sql.append("IF EXISTS ");
+        }
+        return sql.append("FOR ").append(user).append(" SERVER ").append(server);
+    }
+
+    @Override
+    public String toString() {
+        return appendTo(new StringBuilder()).toString();
+    }
+
+    @Override
+    public <T, S> T accept(StatementVisitor<T> visitor, S context) {
+        return visitor.visit(this, context);
+    }
+}

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

@@ -176,6 +176,7 @@
 import net.sf.jsqlparser.statement.delete.ParenthesedDelete;
 import net.sf.jsqlparser.statement.drop.Drop;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.execute.Execute;
 import net.sf.jsqlparser.statement.execute.ExecuteArgument;
 import net.sf.jsqlparser.statement.export.Export;
@@ -3247,6 +3248,12 @@ public <S> Void visit(AlterUserMapping statement, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(DropUserMapping statement, S context) {
+        // User and server names do not refer to tables.
+        return null;
+    }
+
     @Override
     public <S> Void visit(CreateAccessMethod statement, S context) {
         return null;

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

@@ -27,6 +27,7 @@
 import net.sf.jsqlparser.statement.alter.AlterTrigger;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
 import net.sf.jsqlparser.statement.alter.AlterStatistics;
 import net.sf.jsqlparser.statement.alter.AlterRelation;
@@ -1003,6 +1004,11 @@ public <S> StringBuilder visit(AlterUserMapping statement, S context) {
                 expression -> expression.accept(expressionDeParser, context));
     }
 
+    @Override
+    public <S> StringBuilder visit(DropUserMapping statement, S context) {
+        return statement.appendTo(builder);
+    }
+
     @Override
     public <S> StringBuilder visit(CreateAccessMethod statement, S context) {
         return statement.appendTo(builder);

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

@@ -13,6 +13,7 @@
 import net.sf.jsqlparser.statement.alter.AlterTablespace;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
 
 import net.sf.jsqlparser.statement.create.accessmethod.CreateAccessMethod;
@@ -1292,6 +1293,12 @@ public <S> Void visit(AlterUserMapping statement, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(DropUserMapping statement, S context) {
+        validateFeature(Feature.drop);
+        return null;
+    }
+
     @Override
     public <S> Void visit(CreateAccessMethod statement, S context) {
         validateFeature(Feature.createAccessMethod);

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

@@ -4868,6 +4868,11 @@ Statement SingleStatement() :
             |
             LOOKAHEAD(<K_DROP> <K_POLICY>) stm = DropPolicy()
             |
+            LOOKAHEAD({ getToken(1).kind == K_DROP && getToken(2).kind == K_USER
+                    && "MAPPING".equalsIgnoreCase(getToken(3).image)
+                    && (getToken(4).kind == K_FOR || getToken(4).kind == K_IF) })
+            stm = DropUserMapping()
+            |
             stm = Drop()
             |
             LOOKAHEAD({ getToken(1).kind == K_REASSIGN && "OWNED".equalsIgnoreCase(getToken(2).image) })
@@ -19994,7 +19999,7 @@ Drop Drop():
     List<AlgorithmOrLockOption> indexOptions = new ArrayList<AlgorithmOrLockOption>();
     int indexOptionPosition = 0;
     boolean useTemporary = false;
-    boolean foreign = false;
+    String foreignType = null;
     boolean eventTrigger = false;
     CascadeBehavior behavior = null;
     String engine;
@@ -20003,7 +20008,11 @@ Drop Drop():
     <K_DROP>
     [ <K_MATERIALIZED> { drop.setMaterialized(true);} ]
     (
-        <K_FOREIGN> tk=<K_TABLE> { foreign = true; }
+        <K_FOREIGN> (
+            <K_TABLE> { foreignType = "FOREIGN TABLE"; }
+            |
+            <K_DATA> ContextualKeyword("WRAPPER") { foreignType = "FOREIGN DATA WRAPPER"; }
+        )
         |
         // PostgreSQL DROP OWNED BY role [, ...]
         LOOKAHEAD({ isKeywordAhead("OWNED") && getToken(2).kind == K_BY }) tk=<S_IDENTIFIER> <K_BY>
@@ -20051,7 +20060,7 @@ Drop Drop():
         |
         tk=<K_GROUP>
     )
-    { drop.setType(foreign ? "FOREIGN TABLE" : eventTrigger ? "EVENT TRIGGER" : tk.image); }
+    { drop.setType(foreignType != null ? foreignType : eventTrigger ? "EVENT TRIGGER" : tk.image); }
     [ LOOKAHEAD({ drop.getObjectType() == Drop.ObjectType.INDEX
             && getToken(1).kind == K_CONCURRENTLY })
         <K_CONCURRENTLY> { drop.setConcurrently(true); } ]
@@ -25252,6 +25261,18 @@ CreateUserMapping CreateUserMapping():
     { return statement; }
 }
 
+DropUserMapping DropUserMapping():
+{
+    DropUserMapping statement = new DropUserMapping(); String name;
+}
+{
+    <K_DROP> <K_USER> ContextualKeyword("MAPPING")
+    [ LOOKAHEAD(2) <K_IF> <K_EXISTS> { statement.setIfExists(true); } ]
+    <K_FOR> name=RelObjectName() { statement.setUser(name); }
+    ContextualKeyword("SERVER") name=RelObjectName() { statement.setServer(name); }
+    { return statement; }
+}
+
 AlterUserMapping AlterUserMapping():
 {
     AlterUserMapping statement = new AlterUserMapping(); String name; List<ForeignDataOption> options;

src/test/java/net/sf/jsqlparser/statement/create/PostgreSqlForeignDataObjectsTest.java

@@ -12,11 +12,14 @@
 import static org.junit.jupiter.api.Assertions.*;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.NullValue;
 import net.sf.jsqlparser.expression.StringValue;
 import net.sf.jsqlparser.parser.CCJSqlParserUtil;
+import net.sf.jsqlparser.schema.Table;
+import net.sf.jsqlparser.statement.CascadeBehavior;
 import net.sf.jsqlparser.statement.Statement;
 import net.sf.jsqlparser.statement.StatementVisitorAdapter;
 import net.sf.jsqlparser.statement.alter.AlterForeignDataWrapper;
@@ -27,6 +30,8 @@
 import net.sf.jsqlparser.statement.create.server.CreateServer;
 import net.sf.jsqlparser.statement.create.table.ForeignDataOption;
 import net.sf.jsqlparser.statement.create.usermapping.CreateUserMapping;
+import net.sf.jsqlparser.statement.drop.Drop;
+import net.sf.jsqlparser.statement.drop.DropUserMapping;
 import net.sf.jsqlparser.statement.foreign.ForeignDataStatement;
 import net.sf.jsqlparser.util.TablesNamesFinder;
 import net.sf.jsqlparser.util.deparser.StatementDeParser;
@@ -70,6 +75,50 @@ void foreignObjectsShareOptionsAndKeepBoundaries(String sql) throws JSQLParserEx
         assertFalse(new Validation(List.of(FeaturesAllowed.SELECT), sql).validate().isEmpty());
     }
 
+    @ParameterizedTest
+    @ValueSource(strings = {"DROP FOREIGN DATA WRAPPER w",
+            "DROP FOREIGN DATA WRAPPER IF EXISTS w1, w2 CASCADE",
+            "DROP FOREIGN DATA WRAPPER w RESTRICT",
+            "DROP USER MAPPING FOR CURRENT_USER SERVER s",
+            "DROP USER MAPPING IF EXISTS FOR PUBLIC SERVER s",
+            "DROP USER MAPPING FOR USER SERVER s",
+            "DROP USER MAPPING FOR \"user name\" SERVER \"server name\""})
+    void dropsForeignDataObjects(String sql) throws JSQLParserException {
+        Statement statement = CCJSqlParserUtil.parse(sql);
+        assertEquals(sql, statement.toString());
+        assertTrue(new TablesNamesFinder().getTables(statement).isEmpty());
+        roundTrip(statement);
+        assertEquals(2, CCJSqlParserUtil.parseStatements(sql + "; SELECT 1").size());
+        assertTrue(new Validation(List.of(FeaturesAllowed.DDL), sql).validate().isEmpty());
+        assertFalse(new Validation(List.of(FeaturesAllowed.SELECT), sql).validate().isEmpty());
+    }
+
+    @Test
+    void dropStatementsKeepObjectKindAndMappingKey() throws JSQLParserException {
+        Drop wrapper = (Drop) CCJSqlParserUtil.parse(
+                "DROP FOREIGN DATA WRAPPER IF EXISTS w1, w2 CASCADE");
+        assertEquals(Drop.ObjectType.FOREIGN_DATA_WRAPPER, wrapper.getObjectType());
+        assertEquals(List.of("w1", "w2"),
+                wrapper.getNames().stream().map(Table::getFullyQualifiedName)
+                        .collect(Collectors.toList()));
+        assertTrue(wrapper.isIfExists());
+        assertEquals(CascadeBehavior.CASCADE, wrapper.getBehavior());
+
+        DropUserMapping mapping = (DropUserMapping) CCJSqlParserUtil.parse(
+                "DROP USER MAPPING IF EXISTS FOR CURRENT_USER SERVER s");
+        assertTrue(mapping.isIfExists());
+        assertEquals("CURRENT_USER", mapping.getUser());
+        assertEquals("s", mapping.getServer());
+        mapping.setIfExists(false);
+        mapping.setServer("s2");
+        assertEquals("DROP USER MAPPING FOR CURRENT_USER SERVER s2", mapping.toString());
+        roundTrip(mapping);
+
+        // MAPPING followed by neither FOR nor IF is still a user name
+        Drop user = (Drop) CCJSqlParserUtil.parse("DROP USER mapping");
+        assertEquals(Drop.ObjectType.USER, user.getObjectType());
+    }
+
     @Test
     void omittedAndRemovedHandlersStayDistinct() throws JSQLParserException {
         CreateForeignDataWrapper create = (CreateForeignDataWrapper) CCJSqlParserUtil.parse(
@@ -210,7 +259,9 @@ public <S> String visit(CreateUserMapping statement, S context) {
             "ALTER SERVER s OPTIONS(SET x)", "ALTER SERVER s OPTIONS(DROP x 'y')",
             "ALTER SERVER s OPTIONS()", "ALTER SERVER s OPTIONS(host = 'localhost')",
             "CREATE SERVER s TYPE NULL FOREIGN DATA WRAPPER w", "ALTER SERVER s VERSION 18",
-            "ALTER SERVER s RENAME TO s2 OPTIONS(x 'y')"})
+            "ALTER SERVER s RENAME TO s2 OPTIONS(x 'y')",
+            "DROP USER MAPPING FOR u", "DROP USER MAPPING FOR u SERVER s CASCADE",
+            "DROP USER MAPPING IF EXISTS u SERVER s"})
     void rejectsWrongObjectAndOptionForms(String sql) {
         assertThrows(JSQLParserException.class, () -> CCJSqlParserUtil.parse(sql));
     }