add support for drop column if exists (#1594)

JSQLParser · Jul 19, 2022 · fcfdfb7 · fcfdfb7
1 parent 191b9fd
commit fcfdfb7
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Showing 3 changed files with 18 additions and 0 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
@@ -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 ");
  }

diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -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"); } ]

diff --git a/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java b/src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java
@@ -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");
+ }
 }