fix: validate INTO OUTFILE, DUMPFILE and INTO TEMP as selectInto

src/main/java/net/sf/jsqlparser/util/validation/feature/MariaDbVersion.java

@@ -28,7 +28,8 @@ public enum MariaDbVersion implements Version {
                     Feature.jdbcParameter,
                     Feature.jdbcNamedParameter, // expressions
                     Feature.exprLike, // https://mariadb.com/kb/en/select/
-                    Feature.select,
+                    Feature.select, // https://mariadb.com/kb/en/selectinto/
+                    Feature.selectInto,
                     Feature.selectGroupBy, Feature.function,
                     Feature.selectHaving,
                     Feature.limit, Feature.limitOffset, Feature.offset, Feature.offsetParam,

src/main/java/net/sf/jsqlparser/util/validation/feature/MySqlVersion.java

@@ -28,7 +28,8 @@ public enum MySqlVersion implements Version {
                     Feature.jdbcParameter,
                     Feature.jdbcNamedParameter, // expressions
                     Feature.exprLike, // https://dev.mysql.com/doc/refman/8.0/en/select.html
-                    Feature.select,
+                    Feature.select, // https://dev.mysql.com/doc/refman/8.0/en/select-into.html
+                    Feature.selectInto,
                     Feature.selectGroupBy, Feature.selectHaving,
                     Feature.limit, Feature.limitOffset, Feature.offset, Feature.offsetParam,
                     Feature.orderBy,

src/main/java/net/sf/jsqlparser/util/validation/validator/SelectValidator.java

@@ -115,6 +115,9 @@ public <S> Void visit(PlainSelect plainSelect, S context) {
                             || modifier == MySqlSelectModifier.SQL_BUFFER_RESULT),
                     Feature.mysqlSelectModifiers);
             validateOptionalFeature(c, plainSelect.getIntoTables(), Feature.selectInto);
+            validateOptionalFeature(c, plainSelect.getIntoTempTable(), Feature.selectInto);
+            validateOptionalFeature(c, plainSelect.getMySqlSelectIntoClause(),
+                    Feature.selectInto);
             validateOptionalFeature(c, plainSelect.getKsqlWindow(), Feature.kSqlWindow);
             validateFeature(c,
                     isNotEmpty(plainSelect.getOrderByElements()) && plainSelect.isOracleSiblings(),

src/test/java/net/sf/jsqlparser/util/validation/validator/SelectValidatorTest.java

@@ -44,6 +44,22 @@ public void testValidationMySqlSelectModifiers() {
         validateNotSupported(sql, 1, 1, DatabaseType.POSTGRESQL, Feature.mysqlSelectModifiers);
     }
 
+    @ParameterizedTest
+    @ValueSource(strings = {"SELECT a INTO OUTFILE '/tmp/a.txt' FROM t",
+            "SELECT a FROM t INTO OUTFILE '/tmp/a.txt'",
+            "SELECT a FROM t INTO DUMPFILE '/tmp/a.bin'",
+            "SELECT a FROM t WHERE a IN (SELECT b FROM u INTO OUTFILE '/tmp/b.txt')",
+            "SELECT * FROM t INTO TEMP x"})
+    public void testValidationSelectIntoNotAllowed(String sql) {
+        validateNotAllowed(sql, 1, 1, FeaturesAllowed.SELECT, Feature.selectInto);
+    }
+
+    @Test
+    public void testValidationMySqlSelectIntoOutfile() {
+        String sql = "SELECT a FROM t INTO OUTFILE '/tmp/a.txt'";
+        validateNoErrors(sql, 1, DatabaseType.MYSQL, DatabaseType.MARIADB);
+    }
+
     @Test
     public void testValidationSelectDistinct() throws JSQLParserException {
         String sql = "SELECT DISTINCT a, b FROM tab";