Add support for function parameter clauses

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitor.java

@@ -176,6 +176,12 @@ default void visit(Function function) {
         this.visit(function, null);
     }
 
+    <S> T visit(FunctionParameterClauseExpression functionParameterClauseExpression, S context);
+
+    default void visit(FunctionParameterClauseExpression functionParameterClauseExpression) {
+        this.visit(functionParameterClauseExpression, null);
+    }
+
     <S> T visit(SignedExpression signedExpression, S context);
 
     default void visit(SignedExpression signedExpression) {

src/main/java/net/sf/jsqlparser/expression/ExpressionVisitorAdapter.java

@@ -123,6 +123,13 @@ public <S> T visit(Function function, S context) {
         return visitExpressions(function, context, subExpressions);
     }
 
+    @Override
+    public <S> T visit(FunctionParameterClauseExpression functionParameterClauseExpression,
+            S context) {
+        return visitExpressions(functionParameterClauseExpression, context,
+                functionParameterClauseExpression.getExpression());
+    }
+
     @Override
     public <S> T visit(SignedExpression signedExpression, S context) {
         return signedExpression.getExpression().accept(this, context);

src/main/java/net/sf/jsqlparser/expression/Function.java

@@ -16,6 +16,7 @@
 import net.sf.jsqlparser.statement.select.Limit;
 import net.sf.jsqlparser.statement.select.OrderByElement;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -192,6 +193,58 @@ public void setParameters(ExpressionList<?> list) {
         parameters = list;
     }
 
+    /**
+     * Returns the parameter expression at the given index without any attached clause wrapper.
+     * Returns {@code null} if there are no parameters.
+     */
+    public Expression getParameterExpression(int parameterIndex) {
+        if (parameters == null) {
+            return null;
+        }
+
+        Expression parameter = parameters.get(parameterIndex);
+        if (parameter instanceof FunctionParameterClauseExpression) {
+            return ((FunctionParameterClauseExpression) parameter).getExpression();
+        }
+        return parameter;
+    }
+
+    /**
+     * Returns the trailing clause attached to a parameter, e.g. {@code ERROR ON ERROR}, or
+     * {@code null} when no clause is attached.
+     */
+    public String getParameterTrailingClause(int parameterIndex) {
+        if (parameters == null) {
+            return null;
+        }
+
+        Object parameter = parameters.get(parameterIndex);
+        if (parameter instanceof FunctionParameterClauseExpression) {
+            return ((FunctionParameterClauseExpression) parameter).getClause();
+        }
+        return null;
+    }
+
+    /**
+     * Returns one entry per parameter with the attached trailing clause at that index, or
+     * {@code null} when no clause is attached to that parameter.
+     */
+    public List<String> getParameterTrailingClauses() {
+        if (parameters == null) {
+            return Collections.emptyList();
+        }
+
+        List<String> clauses = new ArrayList<>(parameters.size());
+        for (Object parameter : parameters) {
+            if (parameter instanceof FunctionParameterClauseExpression) {
+                clauses.add(((FunctionParameterClauseExpression) parameter).getClause());
+            } else {
+                clauses.add(null);
+            }
+        }
+        return clauses;
+    }
+
     /**
      * the parameters might be named parameters, e.g. substring('foobar' from 2 for 3)
      *

src/main/java/net/sf/jsqlparser/expression/FunctionParameterClauseExpression.java

@@ -0,0 +1,53 @@
+/*-
+ * #%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.expression;
+
+import net.sf.jsqlparser.parser.ASTNodeAccessImpl;
+
+public class FunctionParameterClauseExpression extends ASTNodeAccessImpl implements Expression {
+    private Expression expression;
+    private String clause;
+
+    public FunctionParameterClauseExpression(Expression expression, String clause) {
+        this.expression = expression;
+        this.clause = clause;
+    }
+
+    public Expression getExpression() {
+        return expression;
+    }
+
+    public FunctionParameterClauseExpression setExpression(Expression expression) {
+        this.expression = expression;
+        return this;
+    }
+
+    public String getClause() {
+        return clause;
+    }
+
+    public FunctionParameterClauseExpression setClause(String clause) {
+        this.clause = clause;
+        return this;
+    }
+
+    @Override
+    public <T, S> T accept(ExpressionVisitor<T> expressionVisitor, S context) {
+        return expressionVisitor.visit(this, context);
+    }
+
+    @Override
+    public String toString() {
+        if (clause == null || clause.isEmpty()) {
+            return expression != null ? expression.toString() : "";
+        }
+        return expression + " " + clause;
+    }
+}

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

@@ -429,6 +429,15 @@ public <S> Void visit(Function function, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(FunctionParameterClauseExpression functionParameterClauseExpression,
+            S context) {
+        if (functionParameterClauseExpression.getExpression() != null) {
+            functionParameterClauseExpression.getExpression().accept(this, context);
+        }
+        return null;
+    }
+
     @Override
     public <S> Void visit(GreaterThan greaterThan, S context) {
         visitBinaryExpression(greaterThan);

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

@@ -30,6 +30,7 @@
 import net.sf.jsqlparser.expression.ExpressionVisitor;
 import net.sf.jsqlparser.expression.ExtractExpression;
 import net.sf.jsqlparser.expression.Function;
+import net.sf.jsqlparser.expression.FunctionParameterClauseExpression;
 import net.sf.jsqlparser.expression.HexValue;
 import net.sf.jsqlparser.expression.HighExpression;
 import net.sf.jsqlparser.expression.IntervalExpression;
@@ -939,6 +940,13 @@ public <S> StringBuilder visit(Function function, S context) {
         return builder;
     }
 
+    @Override
+    public <S> StringBuilder visit(
+            FunctionParameterClauseExpression functionParameterClauseExpression, S context) {
+        builder.append(functionParameterClauseExpression);
+        return builder;
+    }
+
     @Override
     public <S> StringBuilder visit(ParenthesedSelect selectBody, S context) {
         selectBody.getSelect().accept(this, context);

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

@@ -11,6 +11,7 @@
 
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.expression.ExpressionVisitor;
+import net.sf.jsqlparser.expression.FunctionParameterClauseExpression;
 import net.sf.jsqlparser.expression.operators.relational.ExpressionList;
 import net.sf.jsqlparser.expression.operators.relational.NamedExpressionList;
 import net.sf.jsqlparser.expression.operators.relational.ParenthesedExpressionList;
@@ -55,7 +56,11 @@ public void deParse(ExpressionList<?> expressionList) {
                 builder.append(name);
                 builder.append(" ");
             }
-            expression.accept(expressionVisitor, null);
+            if (expression instanceof FunctionParameterClauseExpression) {
+                builder.append(expression);
+            } else {
+                expression.accept(expressionVisitor, null);
+            }
             i++;
         }
 

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

@@ -29,6 +29,7 @@
 import net.sf.jsqlparser.expression.ExpressionVisitor;
 import net.sf.jsqlparser.expression.ExtractExpression;
 import net.sf.jsqlparser.expression.Function;
+import net.sf.jsqlparser.expression.FunctionParameterClauseExpression;
 import net.sf.jsqlparser.expression.HexValue;
 import net.sf.jsqlparser.expression.HighExpression;
 import net.sf.jsqlparser.expression.IntervalExpression;
@@ -547,6 +548,13 @@ public <S> Void visit(Function function, S context) {
         return null;
     }
 
+    @Override
+    public <S> Void visit(FunctionParameterClauseExpression functionParameterClauseExpression,
+            S context) {
+        validateOptionalExpression(functionParameterClauseExpression.getExpression(), this);
+        return null;
+    }
+
     @Override
     public <S> Void visit(DateValue dateValue, S context) {
         // nothing to validate