Add 10.3 SEQUENCE test

The test checks that the SEQUENCE related commands return the expected
values.

maxscale-system-test/sequence.cpp

@@ -0,0 +1,38 @@
+/**
+* Test SEQUENCE related commands
+*
+* This test is only enabled when the backend version is 10.3
+*/
+
+#include "testconnections.h"
+#include <vector>
+
+int main(int argc, char** argv)
+{
+    TestConnections::require_repl_version("10.3");
+    TestConnections test(argc, argv);
+
+    test.maxscales->connect();
+    test.try_query(test.maxscales->conn_rwsplit[0], "CREATE SEQUENCE seq");
+
+    std::vector< std::pair<const char*, const char*> > statements =
+    {
+        { "SELECT NEXT VALUE FOR seq", "1" },
+        { "SELECT PREVIOUS VALUE FOR seq", "1" },
+        { "SELECT NEXTVAL(seq)", "2" },
+        { "SELECT LASTVAL(seq)", "2" },
+        { "SELECT seq.nextval", "3" },
+        { "SELECT seq.currval", "3" },
+    };
+
+    for (auto a : statements)
+    {
+        test.assert(execute_query_check_one(test.maxscales->conn_rwsplit[0], a.first, a.second) == 0,
+                    "Expected '%s' for query: %s", a.second, a.first);
+    }
+
+    test.try_query(test.maxscales->conn_rwsplit[0], "DROP SEQUENCE seq");
+    test.maxscales->disconnect();
+
+    return test.global_result;
+}