fix(dameng): use fetch pagination for transfer

crates/dbx-core/src/transfer.rs

@@ -1551,7 +1551,7 @@ pub fn pagination_sql(
     let col_list = columns.iter().map(|c| quote_identifier(c, db_type)).collect::<Vec<_>>().join(", ");
 
     match db_type {
-        DatabaseType::SqlServer | DatabaseType::Oracle => {
+        DatabaseType::SqlServer | DatabaseType::Oracle | DatabaseType::Dameng => {
             format!(
                 "SELECT {col_list} FROM {full_table} ORDER BY (SELECT NULL) OFFSET {offset} ROWS FETCH NEXT {limit} ROWS ONLY"
             )
@@ -1580,7 +1580,7 @@ pub fn pagination_sql_with_order(
     let order_expression = postgres_order_by_expression(order_by_columns, db_type);
 
     match db_type {
-        DatabaseType::SqlServer | DatabaseType::Oracle => {
+        DatabaseType::SqlServer | DatabaseType::Oracle | DatabaseType::Dameng => {
             let order_by = order_expression.unwrap_or_else(|| "(SELECT NULL)".to_string());
             format!(
                 "SELECT {col_list} FROM {full_table} ORDER BY {order_by} OFFSET {offset} ROWS FETCH NEXT {limit} ROWS ONLY"
@@ -1621,7 +1621,7 @@ pub fn pagination_sql_with_filter_order(
         .or_else(|| postgres_order_by_expression(default_order_columns, db_type));
 
     match db_type {
-        DatabaseType::SqlServer | DatabaseType::Oracle => {
+        DatabaseType::SqlServer | DatabaseType::Oracle | DatabaseType::Dameng => {
             let order_by = order_expression.unwrap_or_else(|| "(SELECT NULL)".to_string());
             format!(
                 "SELECT {col_list} FROM {full_table}{where_clause} ORDER BY {order_by} OFFSET {offset} ROWS FETCH NEXT {limit} ROWS ONLY"
@@ -1667,7 +1667,7 @@ pub fn keyset_pagination_sql(
     let where_clause = keyset_where_clause(primary_keys, last_pk_values, db_type);
 
     match db_type {
-        DatabaseType::SqlServer | DatabaseType::Oracle => {
+        DatabaseType::SqlServer | DatabaseType::Oracle | DatabaseType::Dameng => {
             format!(
                 "SELECT {col_list} FROM {full_table}{where_clause} ORDER BY {order} OFFSET 0 ROWS FETCH NEXT {limit} ROWS ONLY"
             )
@@ -3966,6 +3966,43 @@ mod tests {
         assert_eq!(sql, "SELECT `id`, `name` FROM `users` ORDER BY `id` LIMIT 200, 300");
     }
 
+    #[test]
+    fn dameng_export_pagination_uses_offset_fetch() {
+        let sql = pagination_sql(
+            &[String::from("id"), String::from("name")],
+            "users",
+            "SYSDBA",
+            &DatabaseType::Dameng,
+            500,
+            100,
+        );
+
+        assert_eq!(
+            sql,
+            "SELECT \"id\", \"name\" FROM \"SYSDBA\".\"users\" ORDER BY (SELECT NULL) OFFSET 500 ROWS FETCH NEXT 100 ROWS ONLY"
+        );
+        assert!(!sql.contains(" LIMIT "));
+    }
+
+    #[test]
+    fn dameng_ordered_pagination_uses_offset_fetch() {
+        let sql = pagination_sql_with_order(
+            &[String::from("id"), String::from("name")],
+            "users",
+            "SYSDBA",
+            &DatabaseType::Dameng,
+            200,
+            100,
+            &[String::from("id")],
+        );
+
+        assert_eq!(
+            sql,
+            "SELECT \"id\", \"name\" FROM \"SYSDBA\".\"users\" ORDER BY \"id\" OFFSET 200 ROWS FETCH NEXT 100 ROWS ONLY"
+        );
+        assert!(!sql.contains(" LIMIT "));
+    }
+
     #[test]
     fn filtered_pagination_preserves_where_and_order() {
         let sql = pagination_sql_with_filter_order(
@@ -3986,6 +4023,27 @@ mod tests {
         );
     }
 
+    #[test]
+    fn dameng_filtered_pagination_preserves_where_and_order() {
+        let sql = pagination_sql_with_filter_order(
+            &[String::from("id"), String::from("status")],
+            "users",
+            "SYSDBA",
+            &DatabaseType::Dameng,
+            10_000,
+            2_000,
+            Some("WHERE status = 'active'"),
+            Some("\"id\" DESC"),
+            &[String::from("id")],
+        );
+
+        assert_eq!(
+            sql,
+            "SELECT \"id\", \"status\" FROM \"SYSDBA\".\"users\" WHERE (status = 'active') ORDER BY \"id\" DESC OFFSET 10000 ROWS FETCH NEXT 2000 ROWS ONLY"
+        );
+        assert!(!sql.contains(" LIMIT "));
+    }
+
     #[test]
     fn filtered_count_preserves_where() {
         let sql = count_sql_with_where("users", "public", &DatabaseType::SapHana, Some("WHERE status = 'active'"));
@@ -4011,6 +4069,25 @@ mod tests {
         );
     }
 
+    #[test]
+    fn dameng_keyset_pagination_includes_offset_fetch() {
+        let sql = keyset_pagination_sql(
+            &[String::from("id"), String::from("name")],
+            "users",
+            "SYSDBA",
+            &DatabaseType::Dameng,
+            &[String::from("id")],
+            &[json!(25)],
+            100,
+        );
+
+        assert_eq!(
+            sql,
+            "SELECT \"id\", \"name\" FROM \"SYSDBA\".\"users\" WHERE \"id\" > 25 ORDER BY \"id\" ASC OFFSET 0 ROWS FETCH NEXT 100 ROWS ONLY"
+        );
+        assert!(!sql.contains(" LIMIT "));
+    }
+
     #[test]
     fn composite_keyset_pagination_uses_portable_lexicographic_predicate() {
         let sql = keyset_pagination_sql(