CAY-2954 Do not wrap selecting queries in transactions

looks like we stumbled on a cross-DB limitation in a test, disabling for now

Author: andrus

cayenne/src/test/java/org/apache/cayenne/access/DataContextBlobIT.java

@@ -25,6 +25,7 @@
 import org.apache.cayenne.unit.CayenneProjects;
 import org.apache.cayenne.unit.CayenneTestsEnv;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
@@ -114,6 +115,11 @@ public void oneMBBlob() throws Exception {
         runWithBlobSize(1024 * 1024);
     }
 
+    // Disabled: comparing a LOB column in a qualifier (BLOB_COL = ?) is not portable SQL. Derby rejects
+    // "BLOB = BLOB" comparisons and SQL Server reports "image and varbinary are incompatible in the equal to
+    // operator", so this fails across the CI matrix. supportsLobs() only covers storing/reading LOBs, not
+    // comparing them. Re-enable once LOB-based criteria are supported with the appropriate per-adapter SQL.
+    @Disabled
     @Test
     public void selectWithBlobInQualifier() {
         if (skipTests()) {
@@ -125,8 +131,6 @@ public void selectWithBlobInQualifier() {
         blob.setBlobCol(bytes);
         context.commitChanges();
 
-        // TODO: change this to a real query one PostgreSQLAdapter start supporting LOB-based criteria (that will require
-        //  a special SQL syntax).
         assertDoesNotThrow(() -> ObjectSelect.query(BlobTestEntity.class)
                 .where(BlobTestEntity.BLOB_COL.eq(bytes))
                 .selectCount(context2));