fix: share expression-aware table constraint rendering

src/main/java/net/sf/jsqlparser/statement/create/table/CheckConstraint.java

@@ -11,6 +11,7 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.function.Consumer;
 
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.schema.Table;
@@ -52,16 +53,20 @@ public void setEnforced(Boolean enforced) {
     }
 
     @Override
-    public String toString() {
-        StringBuilder b = new StringBuilder();
+    public void appendTo(StringBuilder b, Consumer<Expression> expressionPrinter) {
         appendConstraintPrefixTo(b);
-        b.append("CHECK (").append(expression).append(")");
+        b.append("CHECK (");
+        if (expression == null) {
+            b.append("null");
+        } else {
+            expressionPrinter.accept(expression);
+        }
+        b.append(')');
         if (enforced != null) {
             b.append(enforced ? " ENFORCED" : " NOT ENFORCED");
         }
         appendConstraintSuffixTo(b);
         appendConstraintAttributesTo(b);
-        return b.toString();
     }
 
     public CheckConstraint withTable(Table table) {

src/main/java/net/sf/jsqlparser/statement/create/table/ExcludeConstraint.java

@@ -11,9 +11,9 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.function.Consumer;
 
 import net.sf.jsqlparser.expression.Expression;
-import net.sf.jsqlparser.statement.select.PlainSelect;
 
 public class ExcludeConstraint extends Index {
 
@@ -33,8 +33,7 @@ public void setExpression(Expression expression) {
     }
 
     @Override
-    public String toString() {
-        StringBuilder exclusionStatement = new StringBuilder();
+    public void appendTo(StringBuilder exclusionStatement, Consumer<Expression> expressionPrinter) {
         if (getName() != null) {
             exclusionStatement.append("CONSTRAINT ").append(getName()).append(' ');
         }
@@ -43,15 +42,16 @@ public String toString() {
             exclusionStatement.append(" USING ").append(getUsing());
         }
         if (getColumns() != null) {
-            exclusionStatement.append(' ')
-                    .append(PlainSelect.getStringList(getColumns(), true, true));
+            exclusionStatement.append(' ');
+            appendColumnsTo(exclusionStatement, expressionPrinter);
         }
-        appendConstraintOptionsTo(exclusionStatement);
+        appendConstraintOptionsTo(exclusionStatement, expressionPrinter);
         if (expression != null) {
-            exclusionStatement.append(" WHERE (").append(expression).append(')');
+            exclusionStatement.append(" WHERE (");
+            expressionPrinter.accept(expression);
+            exclusionStatement.append(')');
         }
         appendConstraintAttributesTo(exclusionStatement);
-        return exclusionStatement.toString();
     }
 
     public ExcludeConstraint withExpression(Expression expression) {

src/main/java/net/sf/jsqlparser/statement/create/table/ForeignKeyIndex.java

@@ -20,6 +20,8 @@
 import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.function.Consumer;
+import net.sf.jsqlparser.expression.Expression;
 import java.util.Optional;
 import java.util.Set;
 
@@ -165,8 +167,9 @@ public void setOnUpdateReferenceOption(String onUpdateReferenceOption) {
     }
 
     @Override
-    public String toString() {
-        StringBuilder b = new StringBuilder(super.toString()).append(" ");
+    public void appendTo(StringBuilder b, Consumer<Expression> expressionPrinter) {
+        super.appendTo(b, expressionPrinter);
+        b.append(' ');
         if (reference != null) {
             b.append(reference);
         } else {
@@ -176,7 +179,6 @@ public String toString() {
         }
         appendConstraintSuffixTo(b);
         appendConstraintAttributesTo(b);
-        return b.toString();
     }
 
     public ForeignKeyIndex withTable(Table table) {

src/main/java/net/sf/jsqlparser/statement/create/table/Index.java

@@ -111,11 +111,17 @@ public String nullsDistinctClause() {
     }
 
     public void appendConstraintOptionsTo(StringBuilder sql) {
+        appendConstraintOptionsTo(sql, sql::append);
+    }
+
+    public void appendConstraintOptionsTo(StringBuilder sql,
+            Consumer<Expression> expressionPrinter) {
         if (includeColumns != null) {
             sql.append(" INCLUDE ").append(PlainSelect.getStringList(includeColumns, true, true));
         }
         if (storageParameters != null) {
-            sql.append(" WITH ").append(PlainSelect.getStringList(storageParameters, true, true));
+            sql.append(" WITH ");
+            Option.appendListTo(sql, storageParameters, expressionPrinter);
         }
         if (tableSpace != null) {
             sql.append(" USING INDEX TABLESPACE ").append(tableSpace);
@@ -283,31 +289,49 @@ public Index withIndexKeyword(String indexKeyword) {
 
     @Override
     public String toString() {
+        StringBuilder sql = new StringBuilder();
+        appendTo(sql, sql::append);
+        return sql.toString();
+    }
+
+    /** Renders index definitions through the supplied expression writer. */
+    public void appendTo(StringBuilder sql, Consumer<Expression> expressionPrinter) {
         String idxSpecText = PlainSelect.getStringList(idxSpec, false, false);
         String keyword = indexKeyword != null
                 && (type == null || !type.toUpperCase(java.util.Locale.ROOT)
                         .endsWith(indexKeyword.toUpperCase(java.util.Locale.ROOT)))
                                 ? " " + indexKeyword
                                 : "";
-        String head =
-                (type != null ? type : "") +
-                        keyword +
-                        (!name.isEmpty() ? " " + getName() : "") +
-                        (using != null ? " USING " + using : "");
-
-        String tail = (columns != null && !columns.isEmpty()
-                ? PlainSelect.getStringList(columns, true, true)
-                : "")
-                + (!idxSpecText.isEmpty() ? " " + idxSpecText : "");
-
-        StringBuilder sql = new StringBuilder(head).append(nullsDistinctClause())
-                .append(clusteringClause());
-        if (!tail.isEmpty()) {
-            sql.append(' ').append(tail);
-        }
-        appendConstraintOptionsTo(sql);
+        sql.append(type != null ? type : "").append(keyword);
+        if (!name.isEmpty()) {
+            sql.append(' ').append(getName());
+        }
+        if (using != null) {
+            sql.append(" USING ").append(using);
+        }
+        sql.append(nullsDistinctClause()).append(clusteringClause());
+        boolean hasColumns = columns != null && !columns.isEmpty();
+        if (hasColumns) {
+            sql.append(' ');
+            appendColumnsTo(sql, expressionPrinter);
+        }
+        if (!idxSpecText.isEmpty()) {
+            sql.append(hasColumns ? " " : "  ").append(idxSpecText);
+        }
+        appendConstraintOptionsTo(sql, expressionPrinter);
         appendConstraintAttributesTo(sql);
-        return sql.toString();
+    }
+
+    /** Appends a parenthesized list of keys, including expression keys and operator options. */
+    protected void appendColumnsTo(StringBuilder sql, Consumer<Expression> expressionPrinter) {
+        sql.append('(');
+        for (int i = 0; i < columns.size(); i++) {
+            if (i > 0) {
+                sql.append(", ");
+            }
+            columns.get(i).appendTo(sql, expressionPrinter);
+        }
+        sql.append(')');
     }
 
     public Index withType(String type) {

src/main/java/net/sf/jsqlparser/statement/create/table/NamedConstraint.java

@@ -11,6 +11,8 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.function.Consumer;
+import net.sf.jsqlparser.expression.Expression;
 
 import net.sf.jsqlparser.statement.select.PlainSelect;
 
@@ -81,32 +83,34 @@ public void setUseConstraintKeyword(boolean useConstraintKeyword) {
     }
 
     @Override
-    public String toString() {
+    public void appendTo(StringBuilder sql, Consumer<Expression> expressionPrinter) {
         String idxSpecText = PlainSelect.getStringList(getIndexSpec(), false, false);
         String keyword = getIndexKeyword() != null
                 && !getType().toUpperCase(java.util.Locale.ROOT)
                         .endsWith(getIndexKeyword().toUpperCase(java.util.Locale.ROOT))
                                 ? " " + getIndexKeyword()
                                 : "";
-        String tail = getType()
-                + nullsDistinctClause()
-                + keyword
-                + clusteringClause()
-                + (indexName != null ? " " + indexName : "")
-                + (getUsing() != null ? " USING " + getUsing() : "")
-                + (getColumns() == null ? ""
-                        : " " + PlainSelect.getStringList(getColumnsNames(), true, true))
-                +
-                (!"".equals(idxSpecText) ? " " + idxSpecText : "");
-        StringBuilder sql = new StringBuilder();
         appendConstraintPrefixTo(sql);
-        sql.append(tail);
-        appendConstraintOptionsTo(sql);
+        sql.append(getType()).append(nullsDistinctClause()).append(keyword)
+                .append(clusteringClause());
+        if (indexName != null) {
+            sql.append(' ').append(indexName);
+        }
+        if (getUsing() != null) {
+            sql.append(" USING ").append(getUsing());
+        }
+        if (getColumns() != null) {
+            sql.append(' ');
+            appendColumnsTo(sql, expressionPrinter);
+        }
+        if (!idxSpecText.isEmpty()) {
+            sql.append(' ').append(idxSpecText);
+        }
+        appendConstraintOptionsTo(sql, expressionPrinter);
         if (getKind() != Kind.FOREIGN_KEY) {
             appendConstraintSuffixTo(sql);
             appendConstraintAttributesTo(sql);
         }
-        return sql.toString();
     }
 
     public NamedConstraint withIndexName(String indexName) {

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

@@ -13,7 +13,7 @@
 import net.sf.jsqlparser.expression.ExpressionVisitor;
 import net.sf.jsqlparser.statement.alter.AlterExpression;
 import net.sf.jsqlparser.statement.alter.AlterExpressionPrimaryKey;
-import net.sf.jsqlparser.statement.create.table.DefaultConstraint;
+import net.sf.jsqlparser.statement.alter.AlterOperation;
 import net.sf.jsqlparser.statement.select.PlainSelect;
 import java.util.Iterator;
 
@@ -54,9 +54,17 @@ private void deParseAction(AlterExpression action) {
                     expression -> expression.accept(expressionVisitor, null));
             return;
         }
-        if (action.getIndex() instanceof DefaultConstraint) {
+        if (action.getOperation() == AlterOperation.ADD && action.getIndex() != null
+                && action.getConstraintType() == null) {
             builder.append(action.getOperation()).append(' ');
             new TableElementDeParser(builder, expressionVisitor).deParse(action.getIndex());
+            if (action.getConstraints() != null && !action.getConstraints().isEmpty()) {
+                builder.append(' ')
+                        .append(PlainSelect.getStringList(action.getConstraints(), false, false));
+            }
+            if (action.getUseEqual()) {
+                builder.append('=');
+            }
             deParseTail(action);
             return;
         }

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

@@ -9,13 +9,9 @@
  */
 package net.sf.jsqlparser.util.deparser;
 
-import java.util.Iterator;
 import net.sf.jsqlparser.expression.ExpressionVisitor;
-import net.sf.jsqlparser.statement.create.table.CheckConstraint;
 import net.sf.jsqlparser.statement.create.table.ColumnDefinition;
 import net.sf.jsqlparser.statement.create.table.ColumnOption;
-import net.sf.jsqlparser.statement.create.table.DefaultConstraint;
-import net.sf.jsqlparser.statement.create.table.ExcludeConstraint;
 import net.sf.jsqlparser.statement.create.table.Index;
 import net.sf.jsqlparser.statement.create.table.TableElement;
 
@@ -31,13 +27,9 @@ public TableElementDeParser(StringBuilder builder,
 
     @Override
     public void deParse(TableElement element) {
-        if (element instanceof DefaultConstraint) {
-            ((DefaultConstraint) element).appendTo(builder,
+        if (element instanceof Index) {
+            ((Index) element).appendTo(builder,
                     expression -> expression.accept(expressionVisitor, null));
-        } else if (element instanceof ExcludeConstraint) {
-            deParseExclude((ExcludeConstraint) element);
-        } else if (element instanceof CheckConstraint) {
-            deParseCheck((CheckConstraint) element);
         } else if (element instanceof ColumnDefinition
                 && ((ColumnDefinition) element).getColumnOptions() != null) {
             deParseColumn((ColumnDefinition) element);
@@ -64,48 +56,4 @@ private void deParseColumn(ColumnDefinition column) {
         }
     }
 
-    private void deParseExclude(ExcludeConstraint constraint) {
-        if (constraint.getName() != null) {
-            builder.append("CONSTRAINT ").append(constraint.getName()).append(' ');
-        }
-        builder.append("EXCLUDE");
-        if (constraint.getUsing() != null) {
-            builder.append(" USING ").append(constraint.getUsing());
-        }
-        if (constraint.getColumns() != null) {
-            builder.append(" (");
-            for (Iterator<Index.ColumnParams> iterator =
-                    constraint.getColumns().iterator(); iterator.hasNext();) {
-                iterator.next().appendTo(builder,
-                        expression -> expression.accept(expressionVisitor, null));
-                if (iterator.hasNext()) {
-                    builder.append(", ");
-                }
-            }
-            builder.append(')');
-        }
-        constraint.appendConstraintOptionsTo(builder);
-        if (constraint.getExpression() != null) {
-            builder.append(" WHERE (");
-            constraint.getExpression().accept(expressionVisitor, null);
-            builder.append(')');
-        }
-        constraint.appendConstraintAttributesTo(builder);
-    }
-
-    private void deParseCheck(CheckConstraint constraint) {
-        constraint.appendConstraintPrefixTo(builder);
-        builder.append("CHECK (");
-        if (constraint.getExpression() != null) {
-            constraint.getExpression().accept(expressionVisitor, null);
-        } else {
-            builder.append("null");
-        }
-        builder.append(')');
-        if (constraint.getEnforced() != null) {
-            builder.append(constraint.getEnforced() ? " ENFORCED" : " NOT ENFORCED");
-        }
-        constraint.appendConstraintSuffixTo(builder);
-        constraint.appendConstraintAttributesTo(builder);
-    }
 }