move check sql before drop database

tests/system-test/1-insert/insert_drop.py

@@ -31,6 +31,10 @@ class TDTestCase:
         tdSql.execute('create database if not exists test;')
         tdSql.execute('create table test.stb (ts timestamp, c11 int, c12 float ) TAGS(t11 int, t12 int );')
         tdSql.execute('create table test.tb using test.stb TAGS (1, 1);')
+
+        # double comma insert check error
+        tdSql.error("insert into test.tb(ts, c11) values(now,,100)")
+
         sql_list = list()
         for i in range(5):
             sql = f'insert into test.tb values (now-{i}m, {i}, {i});'
@@ -40,8 +44,6 @@ class TDTestCase:
         self.multiThreadRun(tlist)
         tdSql.query(f'select * from information_schema.ins_databases')
 
-        # double comma insert check error
-        tdSql.error("insert into test.tb(ts, c11) values(now,,100)")
 
 
     def stop(self):