Go to the `C:\TDengine` directory from `cmd` and execute TDengine CLI program `taos.exe` directly to connect to the TDengine service and enter the TDengine CLI interface, for example, as follows:
```text
C:\TDengine>taos
Welcome to the TDengine shell from Linux, Client Version:2.0.5.0
Copyright (c) 2017 by TAOS Data, Inc. All rights reserved.
taos> show databases;
name | created_time | ntables | vgroups | replica | quorum | days | keep1,keep2,keep(D) | cache(MB) | blocks | minrows | maxrows | wallevel | fsync | comp | precision | status |
`void udfNormalFunc(char* data, short itype, short ibytes, int numOfRows, long long* ts, char* dataOutput, char* interBuf, char* tsOutput, int* numOfOutput, short otype, short obytes, SUdfInit* buf)`
tdLog.printNoPrefix("==========step1.1 : create a tsma index and checkdata")
tdSql.execute(f"create sma index {DBNAME}.sma_index_name1 on {DBNAME}.{STBNAME} function(max({INT_COL}),max({BINT_COL}),min({INT_COL})) interval(6m,10s) sliding(6m)")
self.__insert_data(rows=self.rows)
tdSql.query(f"select max({INT_COL}), max({BINT_COL}), min({INT_COL}) from {DBNAME}.{STBNAME} interval(6m,10s) sliding(6m)")
tdSql.checkData(0,0,self.rows-1)
tdSql.checkData(0,1,(self.rows-1)*2)
tdSql.checkData(tdSql.queryRows-1,2,0)
# tdSql.checkData(0, 2, 0)
tdLog.printNoPrefix("==========step1.2 : alter table schema, drop col without index")
tdSql.execute(f"alter stable {DBNAME}.{STBNAME} drop column {BINARY_COL}")
tdSql.query(f"select max({INT_COL}), max({BINT_COL}), min({INT_COL}) from {DBNAME}.{STBNAME} interval(6m,10s) sliding(6m)")
tdSql.checkData(0,0,self.rows-1)
tdSql.checkData(0,1,(self.rows-1)*2)
tdSql.checkData(tdSql.queryRows-1,2,0)
tdLog.printNoPrefix("==========step1.3 : alter table schema, drop col with index")
# TODO: TD-18047, can not drop col, when col in tsma-index and tsma-index is not dropped.
tdSql.error(f"alter stable {DBNAME}.stb1 drop column {BINT_COL}")
tdLog.printNoPrefix("==========step1.4 : alter table schema, add col")