From 0244905959cbcd9debc1d6b48b606f1ccf8a3007 Mon Sep 17 00:00:00 2001
From: jxnu-liguobin <dreamylost@outlook.com>
Date: Tue, 26 Dec 2023 18:37:41 +0800
Subject: [PATCH] Fix: mysql comment with `=` (#1936)

* Fix: mysql comment with `=`

* Fix: mysql comment with `=`
---
 .../net/sf/jsqlparser/statement/alter/AlterExpression.java | 7 +++++--
 .../net/sf/jsqlparser/statement/alter/AlterOperation.java  | 2 +-
 src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt  | 1 +
 .../java/net/sf/jsqlparser/statement/alter/AlterTest.java  | 6 ++++++
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java b/src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java
index c5e0f5078..f31de0da3 100644
--- a/src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java
+++ b/src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java
@@ -442,8 +442,11 @@ public String toString() {
             // Oracle Multi Column Drop
             b.append("DROP (").append(PlainSelect.getStringList(pkColumns)).append(')');
         } else {
-            b.append(operation).append(" ");
-
+            if (operation == AlterOperation.COMMENT_WITH_EQUAL_SIGN) {
+                b.append("COMMENT =").append(" ");
+            } else {
+                b.append(operation).append(" ");
+            }
             if (commentText != null) {
                 if (columnName != null) {
                     b.append(columnName).append(" COMMENT ");
diff --git a/src/main/java/net/sf/jsqlparser/statement/alter/AlterOperation.java b/src/main/java/net/sf/jsqlparser/statement/alter/AlterOperation.java
index d1791cc8b..adddaa14d 100644
--- a/src/main/java/net/sf/jsqlparser/statement/alter/AlterOperation.java
+++ b/src/main/java/net/sf/jsqlparser/statement/alter/AlterOperation.java
@@ -10,7 +10,7 @@
 package net.sf.jsqlparser.statement.alter;
 
 public enum AlterOperation {
-    ADD, ALTER, DROP, DROP_PRIMARY_KEY, DROP_UNIQUE, DROP_FOREIGN_KEY, MODIFY, CHANGE, ALGORITHM, RENAME, RENAME_TABLE, RENAME_INDEX, RENAME_KEY, RENAME_CONSTRAINT, COMMENT, UNSPECIFIC;
+    ADD, ALTER, DROP, DROP_PRIMARY_KEY, DROP_UNIQUE, DROP_FOREIGN_KEY, MODIFY, CHANGE, ALGORITHM, RENAME, RENAME_TABLE, RENAME_INDEX, RENAME_KEY, RENAME_CONSTRAINT, COMMENT, COMMENT_WITH_EQUAL_SIGN, UNSPECIFIC;
 
     public static AlterOperation from(String operation) {
         return Enum.valueOf(AlterOperation.class, operation.toUpperCase());
diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
index 37b7a329f..3144b3103 100644
--- a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
+++ b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -6500,6 +6500,7 @@ AlterExpression AlterExpression():
       )
       |
       (<K_COMMENT> {alterExp.setOperation(AlterOperation.COMMENT);}
+          ["=" {alterExp.setOperation(AlterOperation.COMMENT_WITH_EQUAL_SIGN);} ]
           tk=<S_CHAR_LITERAL> { alterExp.setCommentText(tk.image); }
       )
       |
diff --git a/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java b/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
index c399bcb71..ab07437a6 100644
--- a/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
+++ b/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
@@ -896,6 +896,12 @@ public void testAlterTableDropColumnIfExists() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN IF EXISTS name");
     }
 
+    @Test
+    public void testAlterTableCommentIssue1935() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE table_name COMMENT = 'New table comment'");
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE table_name COMMENT 'New table comment'");
+    }
+
     @Test
     public void testAlterTableDropMultipleColumnsIfExists() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(