adding bit flag check ability (#293)

* adding bit flag check ability

* Avoiding overriding of values

Co-authored-by: Valfrid Couto <[email protected]>

Author: rikard-acst

DapperExtensions.Test/PredicatesFixture.cs

@@ -147,6 +147,16 @@ public void In_ReturnsSetupPredicate()
                 Assert.AreEqual("Id", predicate.PropertyName);
                 Assert.AreEqual(values, predicate.Collection);
                 Assert.AreEqual(false, predicate.Not);
+            }
+
+            [Test]
+            public void BitEq_ReturnsSetupPredicate()
+            {
+                var predicate = Predicates.Field<PredicateTestEntity>(f => f.Id, Operator.BitEq, 1, false);
+                Assert.AreEqual("Id", predicate.PropertyName);
+                Assert.AreEqual(Operator.BitEq, predicate.Operator);
+                Assert.AreEqual(1, predicate.Value);
+                Assert.AreEqual(false, predicate.Not);
             }
         }
 

DapperExtensions/Predicate/FieldPredicate.cs

@@ -95,8 +95,17 @@ private string GetSql(ISqlGenerator sqlGenerator, IDictionary<string, object> pa
                 return string.Format("({0} {1}IN ({2}))", columnName, Not ? "NOT " : string.Empty, GetParameterString(sqlGenerator, parameters, values));
             }
 
-            var format = (Operator == Operator.Like && Value != null && sqlGenerator.Configuration.Dialect is OracleDialect) ?
+            string format;
+            
+            if (Operator == Operator.BitEq && Value != null)
+            {
+                format = (sqlGenerator.Configuration.Dialect is OracleDialect) ? "BITAND({0}, {2}) {1} {2}" : "{0}&{2} {1} {2}";
+            }
+            else
+            {
+                format = (Operator == Operator.Like && Value != null && sqlGenerator.Configuration.Dialect is OracleDialect) ?
                     "(upper({0}) {1} upper('%'||{2}||'%'))" : "({0} {1} {2})";
+            }
 
             return string.Format(format, columnName, GetOperatorString(), GetParameterName(sqlGenerator, parameters, parameterPropertyName, parentType));
         }

DapperExtensions/Predicate/PredicateEnums.cs

@@ -17,6 +17,11 @@ public enum Operator
         /// </summary>
         Eq,
 
+        /// <summary>
+        /// Bit Equal (flags)
+        /// </summary>
+        BitEq,
+
         /// <summary>
         /// Greater than
         /// </summary>