bug fixed for SchemaStatVisitor. for issue #2306

src/main/java/com/alibaba/druid/sql/visitor/SchemaStatVisitor.java

@@ -641,11 +641,18 @@ public class SchemaStatVisitor extends SQLASTVisitorAdapter {
             if (valueColumn != null) {
                 continue;
             }
-            Object value = SQLEvalVisitorUtils.eval(dbType, item, parameters, false);
-            if (value == SQLEvalVisitor.EVAL_VALUE_NULL) {
-                value = null;
+
+            Object value;
+            if (item instanceof SQLMethodInvokeExpr) {
+                value = item.toString();
+            } else {
+                value = SQLEvalVisitorUtils.eval(dbType, item, parameters, false);
+                if (value == SQLEvalVisitor.EVAL_VALUE_NULL) {
+                    value = null;
+                }
             }
-            condition.getValues().add(value);
+
+            condition.addValue(value);
         }
     }
 

src/main/java/com/alibaba/druid/stat/TableStat.java

@@ -323,6 +323,10 @@ public class TableStat {
             return values;
         }
 
+        public void addValue(Object value) {
+            this.values.add(value);
+        }
+
         @Override
         public int hashCode() {
             final int prime = 31;