ExecuteScalar method is added.

7k8m · 7k8m · commit 2da1535992f2 · 2018-11-23T14:57:41.000+09:00
diff --git a/DirectSQL/Database.cs b/DirectSQL/Database.cs
@@ -122,6 +122,34 @@ public static int ExecuteNonQuery(
         }
 
 
+        public static object ExecuteScalar(
+            string sql,
+            IDbConnection connection,
+            IDbTransaction transaction)
+        {
+            return ExecuteScalar(sql, new ValueTuple<String, object>[0], connection, transaction);
+        }
+
+
+        public static object ExecuteScalar(
+            string sql,
+            (String, object)[] parameters,
+            IDbConnection connection,
+            IDbTransaction transaction)
+        {
+            using (var command = connection.CreateCommand())
+            {
+                command.Transaction = transaction;
+
+                command.CommandText = sql;
+                SetParameters(command, parameters);
+
+                return command.ExecuteScalar();
+
+            }
+        }
+
+
         public static int ExecuteNonQuery(
             string sql,
             IDbConnection connection,
@@ -131,6 +159,7 @@ public static int ExecuteNonQuery(
         }
 
 
+
         public static void Query(
             string sql,
             (String, object)[] parameters,  
diff --git a/TestSqlLiteDatabase/QueryTest.cs b/TestSqlLiteDatabase/QueryTest.cs
@@ -73,6 +73,21 @@ public void TestQuery()
                     }
                 );
 
+                var abcdef = SqlLiteDatabase.ExecuteScalar(
+                    "select TEST_VAL1 from TEST_TABLE",
+                    connection,
+                    transaction
+                );
+                Assert.AreEqual(abcdef, "abcdef");
+
+                var abcdef2 = SqlLiteDatabase.ExecuteScalar(
+                    "select TEST_VAL1 from TEST_TABLE where TEST_VAL1 = @val1",
+                    new (String, object)[] { ValueTuple.Create("@val1", "abcdef") },
+                    connection,
+                    transaction
+                );
+                Assert.AreEqual(abcdef2, "abcdef");
+
             });
         }
 
