From 0411fd46b6c8c9205399b3e52ed4c8e6b61d652f Mon Sep 17 00:00:00 2001
From: t8y2 <1156263951@qq.com>
Date: Wed, 17 Jun 2026 01:00:09 +0800
Subject: [PATCH] fix(jdbc): skip SQL-level row limiting for JDBC connections

---
 crates/dbx-core/src/data_compare.rs             |  5 +++++
 crates/dbx-core/src/database_search_sql.rs      |  3 +++
 crates/dbx-core/src/query_result_sql.rs         |  5 +++++
 crates/dbx-core/src/sql_dialect/table_select.rs | 10 ++++++++++
 crates/dbx-core/src/sql_dialect/tests.rs        |  4 +++-
 5 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/crates/dbx-core/src/data_compare.rs b/crates/dbx-core/src/data_compare.rs
index 33c2cc93a..747a3a058 100644
--- a/crates/dbx-core/src/data_compare.rs
+++ b/crates/dbx-core/src/data_compare.rs
@@ -787,6 +787,11 @@ fn build_data_compare_select_sql(
         );
     }
 
+    // JDBC connections rely on Statement.setMaxRows() for row limiting.
+    if database_type == DatabaseType::Jdbc {
+        return format!("SELECT {select_columns} FROM {table}{order_by};");
+    }
+
     let offset_sql = if offset > 0 { format!(" OFFSET {offset}") } else { String::new() };
     format!("SELECT {select_columns} FROM {table}{order_by} LIMIT {row_limit}{offset_sql};")
 }
diff --git a/crates/dbx-core/src/database_search_sql.rs b/crates/dbx-core/src/database_search_sql.rs
index dc7b0a684..c80d02f7b 100644
--- a/crates/dbx-core/src/database_search_sql.rs
+++ b/crates/dbx-core/src/database_search_sql.rs
@@ -111,6 +111,9 @@ pub fn build_database_search_sql(options: DatabaseSearchSqlOptions) -> Option<Da
         format!("SELECT TOP {limit} * FROM {table} WHERE ({where_clause})")
     } else if options.database_type.is_some_and(uses_fetch_first) {
         format!("SELECT * FROM {table} WHERE ({where_clause}) FETCH FIRST {limit} ROWS ONLY")
+    } else if options.database_type == Some(DatabaseType::Jdbc) {
+        // JDBC connections rely on Statement.setMaxRows() for row limiting.
+        format!("SELECT * FROM {table} WHERE ({where_clause});")
     } else {
         format!("SELECT * FROM {table} WHERE ({where_clause}) LIMIT {limit};")
     };
diff --git a/crates/dbx-core/src/query_result_sql.rs b/crates/dbx-core/src/query_result_sql.rs
index de190bd1a..c388b14e6 100644
--- a/crates/dbx-core/src/query_result_sql.rs
+++ b/crates/dbx-core/src/query_result_sql.rs
@@ -207,6 +207,11 @@ pub fn build_paginated_query_sql(options: PaginatedQuerySqlOptions) -> QuerySqlB
         return ok(add_fetch_first_limit(&statement, safe_limit, safe_offset));
     }
 
+    // JDBC connections rely on Statement.setMaxRows() for row limiting.
+    if options.database_type == Some(DatabaseType::Jdbc) {
+        return ok(format!("{statement};"));
+    }
+
     ok(add_standard_limit(&statement, safe_limit, safe_offset))
 }
 
diff --git a/crates/dbx-core/src/sql_dialect/table_select.rs b/crates/dbx-core/src/sql_dialect/table_select.rs
index 96aa8c665..191882266 100644
--- a/crates/dbx-core/src/sql_dialect/table_select.rs
+++ b/crates/dbx-core/src/sql_dialect/table_select.rs
@@ -123,6 +123,11 @@ pub fn build_table_data_select_sql(options: TableDataSelectSqlOptions) -> String
 
     let offset =
         options.offset.filter(|offset| *offset > 0).map(|offset| format!(" OFFSET {offset}")).unwrap_or_default();
+    // JDBC connections rely on Statement.setMaxRows() for row limiting instead of
+    // SQL-level LIMIT, which is not universally supported across all JDBC drivers.
+    if database_type == Some(DatabaseType::Jdbc) {
+        return format!("SELECT {select_columns} FROM {table_alias}{where_clause}{order};");
+    }
     format!("SELECT {select_columns} FROM {table_alias}{where_clause}{order} LIMIT {limit}{offset};")
 }
 
@@ -170,6 +175,11 @@ pub fn build_table_select_sql(options: TableSelectSqlOptions<'_>) -> String {
         return format!("SELECT TOP ({limit}) {select_columns} FROM {table}{order_by}");
     }
 
+    // JDBC connections rely on Statement.setMaxRows() for row limiting.
+    if database_type == Some(DatabaseType::Jdbc) {
+        return format!("SELECT {select_columns} FROM {table}{order_by};");
+    }
+
     format!("SELECT {select_columns} FROM {table}{order_by} LIMIT {limit};")
 }
 
diff --git a/crates/dbx-core/src/sql_dialect/tests.rs b/crates/dbx-core/src/sql_dialect/tests.rs
index 76a463a1d..e1a48726a 100644
--- a/crates/dbx-core/src/sql_dialect/tests.rs
+++ b/crates/dbx-core/src/sql_dialect/tests.rs
@@ -82,6 +82,8 @@ fn builds_select_sql_with_limit_syntax_for_database_type() {
         }),
         "SELECT \"id\", \"name\" FROM \"DB2INST1\".\"USERS\" ORDER BY \"id\" ASC FETCH FIRST 100 ROWS ONLY"
     );
+    // JDBC connections skip SQL-level row limiting — the JDBC agent handles
+    // it via Statement.setMaxRows() which is universally supported.
     assert_eq!(
         build_table_select_sql(TableSelectSqlOptions {
             database_type: Some(DatabaseType::Jdbc),
@@ -91,7 +93,7 @@ fn builds_select_sql_with_limit_syntax_for_database_type() {
             order_columns: &[],
             limit: 100,
         }),
-        "SELECT * FROM dwd_test_df LIMIT 100;"
+        "SELECT * FROM dwd_test_df;"
     );
     assert_eq!(
         build_table_select_sql(TableSelectSqlOptions {