diff --git a/lastleg-service/src/test/java/com/baiyue/lastleg/returnreceipt/service/ReturnInventoryMovementSqlTest.java b/lastleg-service/src/test/java/com/baiyue/lastleg/returnreceipt/service/ReturnInventoryMovementSqlTest.java
new file mode 100644
index 000000000..b9915e50f
--- /dev/null
+++ b/lastleg-service/src/test/java/com/baiyue/lastleg/returnreceipt/service/ReturnInventoryMovementSqlTest.java
@@ -0,0 +1,42 @@
+package com.baiyue.lastleg.returnreceipt.service;
+
+import com.baiyue.lastleg.returnreceipt.mapper.ReturnInventoryMovementMapper;
+import org.apache.ibatis.builder.annotation.MapperAnnotationBuilder;
+import org.apache.ibatis.session.Configuration;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ReturnInventoryMovementSqlTest {
+    @Test
+    void everyUnionBranchNormalizesAllSixTextColumns() {
+        String[] branches = ReturnInventoryMovementMapper.MOVEMENTS.split("UNION ALL");
+        assertEquals(7, branches.length);
+        for (String branch : branches) {
+            String projection = branch.substring(0, branch.indexOf("FROM"));
+            assertEquals(6, projection.split("COLLATE utf8mb4_unicode_ci", -1).length - 1, branch);
+            assertEquals(6, projection.split("USING utf8mb4", -1).length - 1, branch);
+        }
+    }
+
+    @Test
+    void countAndPageShareNormalizedProjectionAndKeepScopeFilters() {
+        Configuration configuration = new Configuration();
+        new MapperAnnotationBuilder(configuration, ReturnInventoryMovementMapper.class).parse();
+        Map<String, Object> params = Map.of("customerId", "CUSTOMER", "warehouseId", "WAREHOUSE",
+                "skuCode", "SKU", "offset", 0L, "size", 20L);
+        for (String method : new String[]{"platformCount", "platformPage"}) {
+            var boundSql = configuration.getMappedStatement(ReturnInventoryMovementMapper.class.getName() + "." + method)
+                    .getBoundSql(params);
+            String sql = boundSql.getSql();
+            assertEquals(42, sql.split("COLLATE utf8mb4_unicode_ci", -1).length - 1);
+            assertTrue(sql.contains("m.customerId=?"));
+            assertTrue(sql.contains("m.overseasWarehouseId=?"));
+            assertTrue(sql.contains("m.skuCode LIKE CONCAT('%',?,'%')"));
+            assertEquals(method.equals("platformPage") ? 5 : 3, boundSql.getParameterMappings().size());
+        }
+    }
+}