From 0b3f93c1c6110c12e04420ad99d96ecc4be6fb8f Mon Sep 17 00:00:00 2001
From: zbeacon <ibarkov.ua@gmail.com>
Date: Fri, 24 Jul 2020 10:45:19 +0300
Subject: [PATCH] Fix for String filter on empty string received.

---
 .../dao/sql/query/EntityKeyMapping.java       | 41 +++++++++++++++----
 1 file changed, 34 insertions(+), 7 deletions(-)

diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java b/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
index dc2aa3dafc..c6ab10d52f 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
@@ -460,32 +460,59 @@ public class EntityKeyMapping {
         }
         switch (stringFilterPredicate.getOperation()) {
             case EQUAL:
-                stringOperationQuery = String.format("%s = :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s = :%s) or (%s is null and :%s = '')", operationField, paramName, operationField, paramName);
                 break;
             case NOT_EQUAL:
-                stringOperationQuery = String.format("%s != :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s != :%s) or (%s is null and :%s != '')", operationField, paramName, operationField, paramName);
                 break;
             case STARTS_WITH:
                 value += "%";
-                stringOperationQuery = String.format("%s like :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '%%')", operationField, paramName, operationField, paramName);
                 break;
             case ENDS_WITH:
                 value = "%" + value;
-                stringOperationQuery = String.format("%s like :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '%%')", operationField, paramName, operationField, paramName);
                 break;
             case CONTAINS:
                 value = "%" + value + "%";
-                stringOperationQuery = String.format("%s like :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '%%%%')", operationField, paramName, operationField, paramName);
                 break;
             case NOT_CONTAINS:
                 value = "%" + value + "%";
-                stringOperationQuery = String.format("%s not like :%s", operationField, paramName);
+                stringOperationQuery = String.format("%s not like :%s) or (%s is null and :%s != '%%%%')", operationField, paramName, operationField, paramName);
                 break;
         }
         ctx.addStringParameter(paramName, value);
-        return String.format("(%s is not null and %s)", field, stringOperationQuery);
+        return String.format("((%s is not null and %s)", field, stringOperationQuery);
     }
 
+
+//            case EQUAL:
+//    stringOperationQuery = String.format("%s = :%s) or (%s is null and :%s = '')", operationField, paramName, operationField, paramName);
+//                break;
+//            case NOT_EQUAL:
+//    stringOperationQuery = String.format("%s != :%s) or (%s is null and :%s != '')", operationField, paramName, operationField, paramName);
+//                break;
+//            case STARTS_WITH:
+//    value += "%";
+//    stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '')", operationField, paramName, operationField, paramName);
+//                break;
+//            case ENDS_WITH:
+//    value = "%" + value;
+//    stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '')", operationField, paramName, operationField, paramName);
+//                break;
+//            case CONTAINS:
+//    value = "%" + value + "%";
+//    stringOperationQuery = String.format("%s like :%s) or (%s is null and :%s = '')", operationField, paramName, operationField, paramName);
+//                break;
+//            case NOT_CONTAINS:
+//    value = "%" + value + "%";
+//    stringOperationQuery = String.format("%s not like :%s) or (%s is null and :%s != '')", operationField, paramName, operationField, paramName);
+//                break;
+//}
+//        ctx.addStringParameter(paramName, value);
+//                return String.format("((%s is not null and %s)", field, stringOperationQuery);
+
     private String buildNumericPredicateQuery(QueryContext ctx, String field, NumericFilterPredicate numericFilterPredicate) {
         String paramName = getNextParameterName(field);
         ctx.addDoubleParameter(paramName, numericFilterPredicate.getValue().getValue());