fix(parser): support CAST to an array type for MySQL multi-valued indexes

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -9946,7 +9946,13 @@ CastExpression CastExpression():
             ")"
         )
         |
-        type=ColDataType() { retval.setColDataType(type); }
+        (
+            type=ColDataType() { retval.setColDataType(type); }
+            // MySQL casts to an array of the given type when a multi-valued index key part is
+            // defined, e.g. CAST(data->'$.zips' AS UNSIGNED ARRAY). ARRAY reads as a further
+            // word of the type, the way INT UNSIGNED already does.
+            [ <K_ARRAY_LITERAL> { type.setDataType(type.getDataType() + " ARRAY"); } ]
+        )
     )
 
     // BigQuery FORMAT clause

src/test/java/net/sf/jsqlparser/expression/CastExpressionTest.java

@@ -13,6 +13,7 @@
 
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.expression.operators.relational.ParenthesedExpressionList;
+import net.sf.jsqlparser.parser.CCJSqlParserUtil;
 import net.sf.jsqlparser.statement.select.PlainSelect;
 import net.sf.jsqlparser.test.TestUtils;
 import org.junit.jupiter.api.Assertions;
@@ -155,4 +156,18 @@ void testNestedCompositeTypeCastIssue2341() throws JSQLParserException {
         Assertions.assertEquals(1, parenthesedCast.size());
         Assertions.assertInstanceOf(CastExpression.class, parenthesedCast.get(0));
     }
+
+    @Test
+    public void testCastToArrayIssue2490() throws JSQLParserException {
+        // MySQL casts to an array of the given type when a multi-valued index key part is
+        // defined, and accepts the same cast anywhere else an expression is allowed.
+        assertSqlCanBeParsedAndDeparsed("SELECT CAST(data -> '$.zips' AS UNSIGNED ARRAY) FROM t");
+        assertSqlCanBeParsedAndDeparsed("SELECT CAST(x AS CHAR (10) ARRAY) FROM t");
+
+        PlainSelect select = (PlainSelect) CCJSqlParserUtil
+                .parse("SELECT CAST(data -> '$.zips' AS UNSIGNED ARRAY) FROM t");
+        CastExpression cast = Assertions.assertInstanceOf(CastExpression.class,
+                select.getSelectItem(0).getExpression());
+        Assertions.assertEquals("UNSIGNED ARRAY", cast.getColDataType().getDataType());
+    }
 }

src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java

@@ -2414,4 +2414,10 @@ public void testAlterTableAddIndexKeyPartWithPrefixLengthAndDirectionIssue2490()
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE t ADD INDEX i33 (c1 (20) ASC)");
         assertSqlCanBeParsedAndDeparsed("ALTER TABLE t ADD UNIQUE INDEX i34 (c1 (10) DESC)");
     }
+
+    @Test
+    public void testAlterTableAddMultiValuedIndexIssue2490() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed(
+                "ALTER TABLE t ADD INDEX i31 ((CAST(data -> '$.zips' AS UNSIGNED ARRAY)))");
+    }
 }

src/test/java/net/sf/jsqlparser/statement/create/CreateIndexTest.java

@@ -234,4 +234,10 @@ public void testCreateFullTextAndSpatialIndexIssue2490() throws JSQLParserExcept
         assertSqlCanBeParsedAndDeparsed("CREATE FULLTEXT INDEX i18 ON t (body) WITH PARSER ngram");
         assertSqlCanBeParsedAndDeparsed("CREATE SPATIAL INDEX i19 ON t (g)");
     }
+
+    @Test
+    public void testCreateMultiValuedIndexIssue2490() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed(
+                "CREATE INDEX i20 ON t ((CAST(data -> '$.zips' AS UNSIGNED ARRAY)))");
+    }
 }