Fix ALTER deparser dispatch for inactive column metadata

Signed-off-by: minleejae <mmj9808@gmail.com>

Author: minleejae

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

@@ -30,6 +30,16 @@ public void setAttributes(ConstraintAttributes attributes) {
         this.attributes = Objects.requireNonNull(attributes, "attributes");
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -436,8 +436,7 @@ public List<ColumnSetDefault> getColumnSetDefaultList() {
      * existing action-specific API to add or remove entries.
      */
     public List<ColumnDefaultAction> getColumnDefaults() {
-        if (operation != AlterOperation.ALTER || columnSetDefaultList == null
-                || constraintType != null && constraintSymbol != null
+        if (!usesColumnActionBody() || columnSetDefaultList == null
                 || columnDropDefaultList != null && !columnDropDefaultList.isEmpty()) {
             return Collections.emptyList();
         }
@@ -994,10 +993,7 @@ protected void appendBody(StringBuilder b) {
             b.append(optionalSpecifier);
         } else if (hasExplicitConstraintHeader()) {
             toStringConstraintAlter(b);
-        } else if (operation == AlterOperation.ALTER
-                && (columnDropDefaultList != null && !columnDropDefaultList.isEmpty()
-                        || columnSetDefaultList != null && !columnSetDefaultList.isEmpty()
-                        || columnSetVisibilityList != null && !columnSetVisibilityList.isEmpty())) {
+        } else if (usesColumnActionBody()) {
             toStringAlterColumn(b);
         } else if (isSimpleKeywordOperation()) {
             toStringSimpleKeyword(b);
@@ -1014,6 +1010,35 @@ protected void appendBody(StringBuilder b) {
         }
     }
 
+    /**
+     * Whether the selected body renders ALTER COLUMN default or visibility actions. Subclasses
+     * overriding {@link #appendBody(StringBuilder)} must reflect their dispatch here as well.
+     */
+    protected boolean usesColumnActionBody() {
+        return operation == AlterOperation.ALTER && !hasExplicitConstraintHeader()
+                && (columnDropDefaultList != null && !columnDropDefaultList.isEmpty()
+                        || columnSetDefaultList != null && !columnSetDefaultList.isEmpty()
+                        || columnSetVisibilityList != null && !columnSetVisibilityList.isEmpty());
+    }
+
+    /**
+     * Whether this action currently renders its column definitions through the general body.
+     * Inactive column metadata is retained in the AST but must not select a different body when
+     * deparsing. Subclasses with their own body dispatch override this method accordingly.
+     */
+    public boolean hasActiveColumnDefinitions() {
+        return hasColumnDefinitionPayload() && operation != AlterOperation.UNSPECIFIC
+                && !hasExplicitConstraintHeader() && !usesColumnActionBody()
+                && !isSimpleKeywordOperation() && !isRenameOperation() && !isDropSpecialOperation()
+                && operation != AlterOperation.CONVERT && operation != AlterOperation.COLLATE
+                && !isPartitionOperation();
+    }
+
+    /** Whether column definitions take precedence within the general body. */
+    protected boolean hasColumnDefinitionPayload() {
+        return commentText == null && columnName == null && colDataTypeList != null;
+    }
+
     /**
      * Appends the common tail (parameters, index comment) shared by all ALTER expressions.
      */

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

@@ -17,6 +17,16 @@
  */
 public class AlterExpressionCharset extends AlterExpression {
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -18,6 +18,17 @@
  * DROP INDEX/KEY, DROP PRIMARY KEY, DROP UNIQUE, DROP FOREIGN KEY, and DROP PARTITION.
  */
 public class AlterExpressionDrop extends AlterExpression {
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return hasColumnDefinitionPayload() && !isDropSpecialOperation()
+                && getOperation() != AlterOperation.DROP_PARTITION;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -28,6 +28,16 @@ public List<OrderByElement> getOrderByElements() {
         return orderByElements;
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -264,6 +264,16 @@ public void setCoalescePartitionCount(Integer coalescePartitionCount) {
         }
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -31,6 +31,16 @@ public AlterExpressionPrimaryKey() {
         setConstraint(new KeyConstraint().withType("PRIMARY KEY"));
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -42,6 +42,16 @@ public void setTargetName(String name) {
         setColumnName(name);
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return getOperation() == AlterOperation.RENAME && hasColumnDefinitionPayload();
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -33,6 +33,16 @@ public void setStructuredTableOption(TableOption option) {
         super.setUseEqual(false);
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;

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

@@ -40,6 +40,16 @@ public StringBuilder appendTo(StringBuilder builder, Consumer<Expression> expres
         return builder;
     }
 
+    @Override
+    protected boolean usesColumnActionBody() {
+        return false;
+    }
+
+    @Override
+    public boolean hasActiveColumnDefinitions() {
+        return false;
+    }
+
     @Override
     public boolean hasActiveTableDefinition() {
         return false;