fix: some problems of parser and planner

tests/script/tsim/query/session.sim

@@ -65,6 +65,15 @@ sql INSERT INTO dev_002 VALUES('2020-05-13 10:00:00.031', 5)
 sql INSERT INTO dev_002 VALUES('2020-05-13 10:00:00.036', 6)
 sql INSERT INTO dev_002 VALUES('2020-05-13 10:00:00.51', 7)
 
+# vnode does not return the precision of the table
+print ====> create database d1 precision 'us' 
+sql create database d1 precision 'us'
+sql use d1
+sql create table dev_001 (ts timestamp ,i timestamp ,j int)
+sql insert into dev_001 values(1623046993681000,now,1)(1623046993681001,now+1s,2)(1623046993681002,now+2s,3)(1623046993681004,now+5s,4)
+sql create table secondts(ts timestamp,t2 timestamp,i int)
+sql insert into secondts values(1623046993681000,now,1)(1623046993681001,now+1s,2)(1623046993681002,now+2s,3)(1623046993681004,now+5s,4)
+
 $loop_test = 0  
 loop_test_pos:
 
@@ -288,15 +297,6 @@ sql_error sql select count(*) from dev_001 session(ts,0s)
 sql_error select count(*) from dev_001 session(i,1y)
 sql_error select count(*) from dev_001 session(ts,1d) where ts <'2020-05-20 0:0:0'
 
-# vnode does not return the precision of the table
-print ====> create database d1 precision 'us' 
-sql create database d1 precision 'us'
-sql use d1
-sql create table dev_001 (ts timestamp ,i timestamp ,j int)
-sql insert into dev_001 values(1623046993681000,now,1)(1623046993681001,now+1s,2)(1623046993681002,now+2s,3)(1623046993681004,now+5s,4)
-sql create table secondts(ts timestamp,t2 timestamp,i int)
-sql insert into secondts values(1623046993681000,now,1)(1623046993681001,now+1s,2)(1623046993681002,now+2s,3)(1623046993681004,now+5s,4)
-
 #print ====> select count(*) from dev_001 session(ts,1u)
 #sql select _wstartts, count(*) from dev_001 session(ts,1u)
 #print rows: $rows