fix(mariadb): do not automatically parse JSON fields by checking meta

packages/core/src/dialects/mariadb/query.js

@@ -183,14 +183,19 @@ export class MariaDbQuery extends AbstractQuery {
       return;
     }
 
-    for (const _field of Object.keys(this.model.fieldRawAttributesMap)) {
+    const meta = rows.meta;
+    for (const [i, _field] of Object.keys(this.model.fieldRawAttributesMap).entries()) {
       const modelField = this.model.fieldRawAttributesMap[_field];
       if (modelField.type instanceof DataTypes.JSON) {
         // Value is returned as String, not JSON
         rows = rows.map(row => {
-          // JSON fields for MariaDB server 10.5.2+ already results in JSON format, skip JSON.parse
-          // this is due to this https://jira.mariadb.org/browse/MDEV-17832 and how mysql2 connector interacts with MariaDB and JSON fields
-          if (row[modelField.fieldName] && typeof row[modelField.fieldName] === 'string' && !this.connection.info.hasMinVersion(10, 5, 2)) {
+          // JSON fields for MariaDB server 10.5.2+ already results in JSON format so we can skip JSON.parse
+          // In this case the column type field will be MYSQL_TYPE_STRING, but the extended type will indicate 'json'
+          if (
+            row[modelField.fieldName]
+            && typeof row[modelField.fieldName] === 'string'
+            && (!meta[i] || meta[i].dataTypeFormat !== 'json')
+          ) {
             row[modelField.fieldName] = JSON.parse(row[modelField.fieldName]);
           }
 

packages/core/test/integration/json.test.ts

@@ -137,6 +137,32 @@ describe('JSON Querying', () => {
     });
   }
 
+  it('should be able to retrieve json value as object for json fields created in every mariadb release', async () => {
+    // MariaDB does not support native JSON type, it uses longtext instead
+    // MariaDB >=10.5.2 adds a CHECK(json_valid(field)) validator that uses to return a different dataFormat to clients
+    // mariadb connector use this to decide to parse or not a JSON field before sequelize
+    if (dialectName !== 'mariadb') {
+      return;
+    }
+
+    await sequelize.query(`CREATE TABLE Posts (id INTEGER AUTO_INCREMENT PRIMARY KEY, 
+      metaOldJSONtype longtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL,
+      metaNewJSONtype longtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL CHECK(json_valid(metaNewJSONtype)))`);
+
+    const Posts = sequelize.define('Posts', {
+      metaOldJSONtype: DataTypes.JSON,
+      metaNewJSONtype: DataTypes.JSON,
+    }, {
+      freezeTableName: true,
+      timestamps: false,
+    });
+
+    await Posts.create({ metaOldJSONtype: 'some text', metaNewJSONtype: 'some text' });
+
+    const posts = await Posts.findAll({ raw: true });
+    expect(posts[0].metaOldJSONtype).to.equal(posts[0].metaNewJSONtype);
+  });
+
   if (dialect.supports.jsonOperations) {
     it('should be able to retrieve element of array by index', async () => {
       const user = await vars.User.findOne({