JSQLParser
diff --git a/‎src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java‎
Lines changed: 3 additions & 0 deletions b/‎src/main/java/net/sf/jsqlparser/statement/alter/AlterExpression.java‎
Lines changed: 3 additions & 0 deletions
diff --git a/‎src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt‎
Lines changed: 1 addition & 0 deletions b/‎src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt‎
Lines changed: 1 addition & 0 deletions
diff --git a/‎src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java‎
Lines changed: 14 additions & 0 deletions b/‎src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java‎
Lines changed: 14 additions & 0 deletions
@@ -412,6 +412,9 @@ public String toString() {
           if (hasColumn) {
             b.append("COLUMN ");
           }
+          if (usingIfExists) {
+            b.append("IF EXISTS ");
+          }
           if (operation == AlterOperation.RENAME) {
             b.append(columnOldName).append(" TO ");
           }
 
@@ -5991,6 +5991,7 @@ AlterExpression AlterExpression():
                 |
                 (
                     ( LOOKAHEAD(2) <K_COLUMN> { alterExp.hasColumn(true); } )?
+                    [<K_IF> <K_EXISTS> { alterExp.setUsingIfExists(true); } ]
                     (tk=<S_IDENTIFIER>    | tk=<S_QUOTED_IDENTIFIER>) { alterExp.setColumnName(tk.image); }
 
                     [ "INVALIDATE" { alterExp.addParameters("INVALIDATE"); } ]
 
@@ -789,4 +789,18 @@ public void testAlterTableChangeColumnDropDefault() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE a MODIFY (COLUMN b DROP DEFAULT, COLUMN b DROP NOT NULL)", true);
     }
 
+    @Test
+    public void testAlterTableDropColumnIfExists() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN IF EXISTS name");
+    }
+
+    @Test
+    public void testAlterTableDropMultipleColumnsIfExists() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN IF EXISTS name, DROP COLUMN IF EXISTS surname");
+    }
+
+    @Test
+    public void testAlterTableDropMultipleColumnsIfExistsWithParams() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed("ALTER TABLE test DROP COLUMN IF EXISTS name CASCADE, DROP COLUMN IF EXISTS surname CASCADE");
+    }
 }
Original file line number	Diff line number	Diff line change
@@ -412,6 +412,9 @@ public String toString() {
412	412	if (hasColumn) {
413	413	b.append("COLUMN ");
414	414	}
	415	+ if (usingIfExists) {
	416	+ b.append("IF EXISTS ");
	417	+ }
415	418	if (operation == AlterOperation.RENAME) {
416	419	b.append(columnOldName).append(" TO ");
417	420	}
Original file line number	Diff line number	Diff line change
@@ -5991,6 +5991,7 @@ AlterExpression AlterExpression():
5991	5991	\|
5992	5992	(
5993	5993	( LOOKAHEAD(2) <K_COLUMN> { alterExp.hasColumn(true); } )?
	5994	+ [<K_IF> <K_EXISTS> { alterExp.setUsingIfExists(true); } ]
5994	5995	(tk=<S_IDENTIFIER> \| tk=<S_QUOTED_IDENTIFIER>) { alterExp.setColumnName(tk.image); }
5995	5996
5996	5997	[ "INVALIDATE" { alterExp.addParameters("INVALIDATE"); } ]