diff --git a/code/datastudio/src/org.opengauss.mppdbide.view/src/org/opengauss/mppdbide/gauss/format/processor/ExpressionProcessorUtil.java b/code/datastudio/src/org.opengauss.mppdbide.view/src/org/opengauss/mppdbide/gauss/format/processor/ExpressionProcessorUtil.java
index a45a45bdedc64af1b111735caf6f7b9bdb7a9fcd..85b3995a2bd25ae01429a8c26248564797f8a49b 100644
--- a/code/datastudio/src/org.opengauss.mppdbide.view/src/org/opengauss/mppdbide/gauss/format/processor/ExpressionProcessorUtil.java
+++ b/code/datastudio/src/org.opengauss.mppdbide.view/src/org/opengauss/mppdbide/gauss/format/processor/ExpressionProcessorUtil.java
@@ -41,12 +41,12 @@ public class ExpressionProcessorUtil {
 
     static {
         currentPreTextMap.put("=", Arrays.asList(":", ">", "<", "!", "="));
-        currentPreTextMap.put("<", Arrays.asList("=", ">"));
+        currentPreTextMap.put("<", Arrays.asList("=", ">", "<"));
         currentPreTextMap.put(">", Arrays.asList("=", "<"));
         currentPreTextMap.put("!", Arrays.asList("="));
         currentPreTextMap.put(":", Arrays.asList("=", ":"));
         currentPreTextMap.put("|", Arrays.asList("|"));
-
+        currentPreTextMap.put("@", Arrays.asList("<"));
     }
 
     /**