FIXES #20888: Validate EntityLink column existence during test case creation (#22932)

* fix: Validate EntityLink column existence during test case creation

- Update EntityRepository.validateColumn() to use case-insensitive comparison
- Add column existence validation to TestCaseRepository.validateColumnTestCase()
- Prevents test case creation with invalid column references due to case sensitivity

Fixes #20888

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: IceS2 <IceS2@users.noreply.github.com>

* small fix

* Add tests

* Fix test

---------

Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: IceS2 <IceS2@users.noreply.github.com>
Co-authored-by: Shailesh Parmar <shailesh.parmar.webdev@gmail.com>

openmetadata-service/src/main/java/org/openmetadata/service/jdbi3/TestCaseRepository.java

@@ -575,6 +575,12 @@ public class TestCaseRepository extends EntityRepository<TestCase> {
                     + " e.g. <#E::table::{entityFqn}::columns::{columnName}>",
                 entityLink.getFieldName()));
       }
+
+      // Validate that the referenced column actually exists in the table
+      if (entityLink.getArrayFieldName() != null) {
+        Table table = Entity.getEntity(entityLink, "columns", ALL);
+        validateColumn(table, entityLink.getArrayFieldName());
+      }
     }
   }
 

openmetadata-service/src/test/java/org/openmetadata/service/resources/dqtests/TestCaseResourceTest.java

@@ -531,6 +531,38 @@ public class TestCaseResourceTest extends EntityResourceTest<TestCase, CreateTes
         "Parameter 'invalidParameter' is not defined in the test definition. Defined parameters are: [missingValueMatch, missingCountValue]");
   }
 
+  @Test
+  void post_testWithInvalidColumnName_4xx(TestInfo test) {
+    String invalidColumnLink =
+        String.format(
+            "<#E::table::%s::columns::%s>",
+            TEST_TABLE1.getFullyQualifiedName(), "nonExistentColumn");
+    CreateTestCase create =
+        createRequest(test)
+            .withTestDefinition(TEST_DEFINITION2.getFullyQualifiedName())
+            .withEntityLink(invalidColumnLink);
+
+    assertResponseContains(
+        () -> createAndCheckEntity(create, ADMIN_AUTH_HEADERS),
+        BAD_REQUEST,
+        "Invalid column name nonExistentColumn");
+  }
+
+  @Test
+  void post_testWithWrongCaseColumnName_4xx(TestInfo test) {
+    String wrongCaseColumnLink =
+        String.format("<#E::table::%s::columns::%s>", TEST_TABLE1.getFullyQualifiedName(), "C1");
+    CreateTestCase create =
+        createRequest(test)
+            .withTestDefinition(TEST_DEFINITION2.getFullyQualifiedName())
+            .withEntityLink(wrongCaseColumnLink);
+
+    assertResponseContains(
+        () -> createAndCheckEntity(create, ADMIN_AUTH_HEADERS),
+        BAD_REQUEST,
+        "Invalid column name C1");
+  }
+
   @Test
   void createUpdateDelete_tests_200(TestInfo test) throws IOException {
     // Create a test case

openmetadata-service/src/test/java/org/openmetadata/service/resources/lineage/LineageResourceTest.java

@@ -520,10 +520,16 @@ public class LineageResourceTest extends OpenMetadataApplicationTest {
 
     MessageParser.EntityLink TABLE4_COLUMN_LINK =
         MessageParser.EntityLink.parse(
-            String.format("<#E::table::%s::columns::c1>", TABLES.get(4).getFullyQualifiedName()));
+            String.format(
+                "<#E::table::%s::columns::%s>",
+                TABLES.get(4).getFullyQualifiedName(),
+                TABLES.get(4).getColumns().get(0).getName()));
     MessageParser.EntityLink TABLE6_COLUMN_LINK =
         MessageParser.EntityLink.parse(
-            String.format("<#E::table::%s::columns::c1>", TABLES.get(6).getFullyQualifiedName()));
+            String.format(
+                "<#E::table::%s::columns::%s>",
+                TABLES.get(6).getFullyQualifiedName(),
+                TABLES.get(6).getColumns().get(0).getName()));
     CreateTestCase create4 = testCaseResourceTest.createRequest(test);
     CreateTestCase create6 = testCaseResourceTest.createRequest(test, 2);
     create4