From 49cde6ec41aa295c0d9c1a1a019ebc3cd3b48d59 Mon Sep 17 00:00:00 2001
From: onepintwig <willrneedham@googlemail.com>
Date: Wed, 12 Nov 2025 16:37:22 +0000
Subject: [PATCH] [feat] Add 'K_DATA' to KeywordOrIdentifier to allow usages of
 'data' as an identifier

Allows for support of data as a column name when changing or dropping a column in an alter table statement
---
 .../jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt   |  7 ++++---
 .../net/sf/jsqlparser/statement/alter/AlterTest.java   | 10 ++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
index 0f2dd1df6..69afc0734 100644
--- a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
+++ b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -886,7 +886,7 @@ TOKEN:
  * Supported tokens:
  *  - <S_IDENTIFIER>: Standard unquoted SQL identifier
  *  - <S_QUOTED_IDENTIFIER>: Quoted identifier (e.g., `identifier` or "identifier")
- *  - <K_NAME>, <K_NEXT>, <K_VALUE>, <K_PUBLIC>, <K_STRING>: Specific keywords treated as identifiers
+ *  - <K_NAME>, <K_NEXT>, <K_VALUE>, <K_PUBLIC>, <K_STRING>, <K_DATA>: Specific keywords treated as identifiers
  *
  * @return Token representing the identifier or keyword used as identifier
  */
@@ -903,6 +903,7 @@ Token KeywordOrIdentifier():
       | tk = <K_VALUE>
       | tk = <K_PUBLIC>
       | tk = <K_STRING>
+      | tk = <K_DATA>
     )
     { return tk; }
 }
@@ -9414,7 +9415,7 @@ AlterExpression AlterExpression():
         <K_CHANGE> { alterExp.setOperation(AlterOperation.CHANGE); }
         [ <K_COLUMN> { alterExp.hasColumn(true); alterExp.setOptionalSpecifier("COLUMN"); } ]
         (
-          (tk=<S_IDENTIFIER> | tk=<S_QUOTED_IDENTIFIER>)
+          (tk=KeywordOrIdentifier())
           alterExpressionColumnDataType = AlterExpressionColumnDataType() {  alterExp.withColumnOldName(tk.image).addColDataType(alterExpressionColumnDataType); }
         )
       )
@@ -9448,7 +9449,7 @@ AlterExpression AlterExpression():
                     ( LOOKAHEAD(2) <K_COLUMN> { alterExp.hasColumn(true); } )?
                     [<K_IF> <K_EXISTS> { alterExp.setUsingIfExists(true); } ]
                     // @todo: replace with a proper identifier
-                    (tk=<S_IDENTIFIER>  | tk=<S_QUOTED_IDENTIFIER> | tk=<K_NAME>) { alterExp.setColumnName(tk.image); }
+                    (tk=KeywordOrIdentifier() ) { alterExp.setColumnName(tk.image); }
 
                     [ "INVALIDATE" { alterExp.addParameters("INVALIDATE"); } ]
 
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 559517b9d..749e12853 100644
--- a/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
+++ b/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
@@ -249,6 +249,11 @@ public void testAlterTableDropColumn2() throws JSQLParserException {
         assertEquals("col2", col2Exp.getColumnName());
     }
 
+    @Test
+    public void testAlterTableDropColumnIssue2339() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN Data");
+    }
+
     @Test
     public void testAlterTableDropConstraint() throws JSQLParserException {
         final String sql = "ALTER TABLE test DROP CONSTRAINT YYY";
@@ -455,6 +460,11 @@ public void testAlterTableChangeColumn4() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE tb_test CHANGE c1 c2 INT (10)");
     }
 
+    @Test
+    public void testAlterTableChangeColumnIssue2339() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE tb_test CHANGE data INT (10)");
+    }
+
     @Test
     public void testAlterTableAddColumnWithZone() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(