feat: add support for READ_ONLY connection mode in MSSQL plugin

app/server/appsmith-plugins/mssqlPlugin/src/main/java/com/external/plugins/MssqlPlugin.java

@@ -626,6 +626,14 @@ private static HikariDataSource createConnectionPool(
 
         addSslOptionsToUrlBuilder(datasourceConfiguration, urlBuilder);
 
+        // Add connection mode configuration for READ_ONLY
+        if (datasourceConfiguration.getConnection() != null
+                && datasourceConfiguration.getConnection().getMode()
+                        == com.appsmith.external.models.Connection.Mode.READ_ONLY) {
+            urlBuilder.append("ApplicationIntent=ReadOnly;");
+            hikariConfig.setReadOnly(true);
+        }
+
         hikariConfig.setJdbcUrl(urlBuilder.toString());
 
         try {

app/server/appsmith-plugins/mssqlPlugin/src/main/resources/form.json

@@ -9,6 +9,7 @@
           "configProperty": "datasourceConfiguration.connection.mode",
           "controlType": "SEGMENTED_CONTROL",
           "initialValue": "READ_WRITE",
+          "tooltipText": "Read-only mode uses ApplicationIntent=ReadOnly. Note: This only enforces read-only connections when using Always On Availability Groups.",
           "options": [
             {
               "label": "Read / Write",

app/server/appsmith-plugins/mssqlPlugin/src/test/java/com/external/plugins/MssqlPluginTest.java

@@ -773,4 +773,52 @@ public void testGetEndpointIdentifierForRateLimit_HostPresentPortAbsent_ReturnsC
                 })
                 .verifyComplete();
     }
+
+    @Test
+    public void testReadOnlyConnectionMode() {
+        DatasourceConfiguration dsConfig = createDatasourceConfiguration(container);
+
+        // Set connection mode to READ_ONLY
+        com.appsmith.external.models.Connection connection = new com.appsmith.external.models.Connection();
+        connection.setMode(com.appsmith.external.models.Connection.Mode.READ_ONLY);
+        dsConfig.setConnection(connection);
+
+        // Create connection pool
+        HikariDataSource connectionPool =
+                mssqlPluginExecutor.datasourceCreate(dsConfig).block();
+
+        // Verify the JDBC URL contains ApplicationIntent=ReadOnly
+        assertNotNull(connectionPool);
+        String jdbcUrl = connectionPool.getJdbcUrl();
+        assertTrue(
+                jdbcUrl.contains("ApplicationIntent=ReadOnly"),
+                "JDBC URL should contain ApplicationIntent=ReadOnly parameter");
+
+        // Cleanup
+        connectionPool.close();
+    }
+
+    @Test
+    public void testReadWriteConnectionMode() {
+        DatasourceConfiguration dsConfig = createDatasourceConfiguration(container);
+
+        // Set connection mode to READ_WRITE
+        com.appsmith.external.models.Connection connection = new com.appsmith.external.models.Connection();
+        connection.setMode(com.appsmith.external.models.Connection.Mode.READ_WRITE);
+        dsConfig.setConnection(connection);
+
+        // Create connection pool
+        HikariDataSource connectionPool =
+                mssqlPluginExecutor.datasourceCreate(dsConfig).block();
+
+        // Verify the JDBC URL does NOT contain ApplicationIntent parameter
+        assertNotNull(connectionPool);
+        String jdbcUrl = connectionPool.getJdbcUrl();
+        assertTrue(
+                !jdbcUrl.contains("ApplicationIntent"),
+                "JDBC URL should not contain ApplicationIntent parameter for READ_WRITE mode");
+
+        // Cleanup
+        connectionPool.close();
+    }
 }