Support PostgreSQL CREATE and ALTER COLLATION

src/main/java/net/sf/jsqlparser/parser/feature/Feature.java

@@ -580,6 +580,8 @@ public enum Feature {
      */
     createSequence,
     /** Publication and subscription definitions. */
+    createCollation, alterCollation,
+
     createPublication, alterPublication, createSubscription, alterSubscription,
     /**
      * Structured type, domain and extension statements.

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

@@ -9,6 +9,8 @@
  */
 package net.sf.jsqlparser.statement;
 
+import net.sf.jsqlparser.statement.create.collation.CreateCollation;
+import net.sf.jsqlparser.statement.alter.AlterCollation;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
@@ -733,4 +735,20 @@ default <S> T visit(AlterStatistics statement, S context) {
     default void visit(AlterStatistics statement) {
         visit(statement, null);
     }
+
+    default <S> T visit(CreateCollation statement, S context) {
+        return null;
+    }
+
+    default void visit(CreateCollation statement) {
+        visit(statement, null);
+    }
+
+    default <S> T visit(AlterCollation statement, S context) {
+        return null;
+    }
+
+    default void visit(AlterCollation statement) {
+        visit(statement, null);
+    }
 }

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

@@ -0,0 +1,96 @@
+/*-
+ * #%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.alter;
+
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.StatementVisitor;
+
+public class AlterCollation implements Statement {
+    public enum Action {
+        REFRESH_VERSION, RENAME, OWNER, SET_SCHEMA
+    }
+
+    private String name;
+    private Action action;
+    private String newName;
+    private String owner;
+    private String schemaName;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String value) {
+        name = value;
+    }
+
+    public Action getAction() {
+        return action;
+    }
+
+    public void setAction(Action value) {
+        action = value;
+    }
+
+    public String getNewName() {
+        return newName;
+    }
+
+    public void setNewName(String value) {
+        newName = value;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public void setOwner(String value) {
+        owner = value;
+    }
+
+    public String getSchemaName() {
+        return schemaName;
+    }
+
+    public void setSchemaName(String value) {
+        schemaName = value;
+    }
+
+    public StringBuilder appendTo(StringBuilder sql) {
+        sql.append("ALTER COLLATION ").append(name);
+        switch (action) {
+            case REFRESH_VERSION:
+                sql.append(" REFRESH VERSION");
+                break;
+            case RENAME:
+                sql.append(" RENAME TO ").append(newName);
+                break;
+            case OWNER:
+                sql.append(" OWNER TO ").append(owner);
+                break;
+            case SET_SCHEMA:
+                sql.append(" SET SCHEMA ").append(schemaName);
+                break;
+            default:
+                throw new IllegalStateException("Unknown collation action: " + action);
+        }
+        return sql;
+    }
+
+    @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/statement/create/collation/CreateCollation.java

@@ -0,0 +1,96 @@
+/*-
+ * #%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.create.collation;
+
+import java.util.List;
+import java.util.function.Consumer;
+import net.sf.jsqlparser.expression.Expression;
+import net.sf.jsqlparser.statement.Statement;
+import net.sf.jsqlparser.statement.StatementVisitor;
+import net.sf.jsqlparser.statement.create.table.Index;
+
+/** PostgreSQL collation copy or parameter definition, with mutually exclusive forms. */
+public class CreateCollation implements Statement {
+    private String name;
+    private boolean ifNotExists;
+    private String sourceCollation;
+    private List<Index.Option> options;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String value) {
+        name = value;
+    }
+
+    public boolean isIfNotExists() {
+        return ifNotExists;
+    }
+
+    public void setIfNotExists(boolean value) {
+        ifNotExists = value;
+    }
+
+    public String getSourceCollation() {
+        return sourceCollation;
+    }
+
+    public void setSourceCollation(String source) {
+        sourceCollation = source;
+        if (source != null) {
+            options = null;
+        }
+    }
+
+    public List<Index.Option> getOptions() {
+        return options;
+    }
+
+    public void setOptions(List<Index.Option> options) {
+        this.options = options;
+        if (options != null) {
+            sourceCollation = null;
+        }
+    }
+
+    public StringBuilder appendTo(StringBuilder sql, Consumer<Expression> printer) {
+        sql.append("CREATE COLLATION ");
+        if (isIfNotExists()) {
+            sql.append("IF NOT EXISTS ");
+        }
+        sql.append(getName());
+        if (sourceCollation != null) {
+            sql.append(" FROM ").append(sourceCollation);
+        } else {
+            sql.append(' ');
+            Index.Option.appendListTo(sql, options, printer);
+        }
+        return sql;
+    }
+
+    public void visitExpressions(Consumer<Expression> visitor) {
+        if (sourceCollation == null && options != null) {
+            options.stream().map(Index.Option::getValue).filter(java.util.Objects::nonNull)
+                    .forEach(visitor);
+        }
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sql = new StringBuilder();
+        return appendTo(sql, sql::append).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

@@ -9,6 +9,8 @@
  */
 package net.sf.jsqlparser.util;
 
+import net.sf.jsqlparser.statement.create.collation.CreateCollation;
+import net.sf.jsqlparser.statement.alter.AlterCollation;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
@@ -2968,4 +2970,15 @@ public <S> Void visit(CreateStatistics statement, S context) {
     public <S> Void visit(AlterStatistics statement, S context) {
         return null;
     }
+
+    @Override
+    public <S> Void visit(CreateCollation statement, S context) {
+        statement.visitExpressions(expression -> expression.accept(this, context));
+        return null;
+    }
+
+    @Override
+    public <S> Void visit(AlterCollation statement, S context) {
+        return null;
+    }
 }

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

@@ -9,6 +9,8 @@
  */
 package net.sf.jsqlparser.util.deparser;
 
+import net.sf.jsqlparser.statement.create.collation.CreateCollation;
+import net.sf.jsqlparser.statement.alter.AlterCollation;
 import net.sf.jsqlparser.statement.alter.AlterPolicy;
 import net.sf.jsqlparser.statement.drop.DropPolicy;
 import net.sf.jsqlparser.statement.create.statistics.CreateStatistics;
@@ -853,4 +855,15 @@ public <S> StringBuilder visit(CreateStatistics statement, S context) {
     public <S> StringBuilder visit(AlterStatistics statement, S context) {
         return statement.appendTo(builder);
     }
+
+    @Override
+    public <S> StringBuilder visit(CreateCollation statement, S context) {
+        return statement.appendTo(builder,
+                expression -> expression.accept(expressionDeParser, context));
+    }
+
+    @Override
+    public <S> StringBuilder visit(AlterCollation statement, S context) {
+        return statement.appendTo(builder);
+    }
 }

src/main/java/net/sf/jsqlparser/util/validation/feature/FeaturesAllowed.java

@@ -101,6 +101,7 @@ public class FeaturesAllowed implements FeatureSetValidation, ModifyableFeatureS
      * all "CREATE" {@link Feature}'s
      */
     public static final FeaturesAllowed CREATE = new FeaturesAllowed("CREATE", Feature.createIndex,
+            Feature.createCollation,
             Feature.createSchema, Feature.createSequence, Feature.createTable,
             Feature.createTableUnlogged,
             Feature.createTableCreateOptionStrings, Feature.createTableTableOptionStrings,
@@ -113,6 +114,7 @@ public class FeaturesAllowed implements FeatureSetValidation, ModifyableFeatureS
      */
     public static final FeaturesAllowed ALTER =
             new FeaturesAllowed("ALTER", Feature.alterTable, Feature.alterSequence,
+                    Feature.alterCollation,
                     Feature.alterView, Feature.alterIndex, Feature.alterSchema)
                     .unmodifyable();
     /**

src/main/java/net/sf/jsqlparser/util/validation/feature/PostgresqlVersion.java

@@ -97,6 +97,7 @@ public enum PostgresqlVersion implements Version {
 
                     // https://www.postgresql.org/docs/current/sql-createsequence.html
                     Feature.createSequence,
+                    Feature.createCollation, Feature.alterCollation,
                     Feature.createPublication, Feature.alterPublication,
                     Feature.createSubscription, Feature.alterSubscription,
                     Feature.createType, Feature.alterType,

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

@@ -9,6 +9,8 @@
  */
 package net.sf.jsqlparser.util.validation.validator;
 
+import net.sf.jsqlparser.statement.create.collation.CreateCollation;
+import net.sf.jsqlparser.statement.alter.AlterCollation;
 import net.sf.jsqlparser.statement.alter.schema.AlterSchema;
 import net.sf.jsqlparser.statement.oracle.OracleBlock;
 import net.sf.jsqlparser.statement.oracle.OracleAssignment;
@@ -1024,4 +1026,17 @@ public <S> Void visit(OracleNullStatement statement, S context) {
         return null;
     }
 
+
+    @Override
+    public <S> Void visit(CreateCollation statement, S context) {
+        validateFeature(Feature.createCollation);
+        statement.visitExpressions(this::validateOptionalExpression);
+        return null;
+    }
+
+    @Override
+    public <S> Void visit(AlterCollation statement, S context) {
+        validateFeature(Feature.alterCollation);
+        return null;
+    }
 }

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

@@ -49,6 +49,7 @@ import net.sf.jsqlparser.schema.*;
 import net.sf.jsqlparser.statement.*;
 import net.sf.jsqlparser.statement.analyze.*;
 import net.sf.jsqlparser.statement.alter.*;
+import net.sf.jsqlparser.statement.create.collation.CreateCollation;
 import net.sf.jsqlparser.statement.alter.schema.AlterSchema;
 import net.sf.jsqlparser.statement.alter.database.AlterDatabase;
 import net.sf.jsqlparser.statement.alter.sequence.*;
@@ -18441,6 +18442,8 @@ Statement Alter():
         (
             <K_ALTER>
             (
+                LOOKAHEAD({ isKeywordAhead("COLLATION") }) statement = AlterCollation()
+                |
                 LOOKAHEAD({ isKeywordAhead("STATISTICS") }) statement = AlterStatistics()
                 |
                 LOOKAHEAD(<K_POLICY>) statement = AlterPolicy()
@@ -19650,6 +19653,8 @@ Statement Create():
 {
     <K_CREATE> [ <K_OR> <K_REPLACE> { isUsingOrReplace = true; } ]
     (
+        LOOKAHEAD({ isKeywordAhead("COLLATION") }) { requireDdlSyntax(!isUsingOrReplace, "CREATE COLLATION does not support OR REPLACE"); } statement = CreateCollation()
+        |
         LOOKAHEAD({ isKeywordAhead("STATISTICS") }) statement = CreateStatistics()
         |
         LOOKAHEAD({ isPostgreSqlRoleAhead() }) statement = CreateRole()
@@ -20952,3 +20957,36 @@ AlterStatistics AlterStatistics():
               statement.setStatistics(target.intValue()); } ) ) )
     { return statement; }
 }
+
+CreateCollation CreateCollation():
+{
+    CreateCollation statement = new CreateCollation(); String name; List<Index.Option> options;
+}
+{
+    ContextualKeyword("COLLATION")
+    [ LOOKAHEAD(2) <K_IF> <K_NOT> <K_EXISTS> { statement.setIfNotExists(true); } ]
+    name=AccessQualifiedName() { statement.setName(name); }
+    ( <K_FROM> name=AccessQualifiedName() { statement.setSourceCollation(name); }
+      | options=PostgreSqlOptions(true) {
+          for (Index.Option option : options) {
+              requireDdlSyntax(option.getValue() == null || option.isUseEquals(),
+                      "Collation parameter values require an equals sign");
+          }
+          statement.setOptions(options);
+      } )
+    { return statement; }
+}
+
+AlterCollation AlterCollation():
+{ AlterCollation statement = new AlterCollation(); String name; }
+{
+    ContextualKeyword("COLLATION") name=AccessQualifiedName() { statement.setName(name); }
+    ( <K_REFRESH> <K_VERSION> { statement.setAction(AlterCollation.Action.REFRESH_VERSION); }
+      | <K_RENAME> <K_TO> name=RelObjectName()
+        { statement.setAction(AlterCollation.Action.RENAME); statement.setNewName(name); }
+      | <K_SET> <K_SCHEMA> name=RelObjectName()
+        { statement.setAction(AlterCollation.Action.SET_SCHEMA); statement.setSchemaName(name); }
+      | ContextualKeyword("OWNER") <K_TO> name=RelObjectName()
+        { statement.setAction(AlterCollation.Action.OWNER); statement.setOwner(name); } )
+    { return statement; }
+}