test: add a case for concat function

tests/army/query/function/concat.py

@@ -0,0 +1,44 @@
+import taos
+import frame
+import frame.etool
+
+
+from frame.log import *
+from frame.cases import *
+from frame.sql import *
+from frame.caseBase import *
+from frame import *
+
+
+class TDTestCase(TBase):
+    """Verify the concat function
+    """
+    def init(self, conn, logSql, replicaVar=1):
+        self.replicaVar = int(replicaVar)
+        tdSql.init(conn.cursor())
+        self.dbname = 'db'
+        self.tbname = f'{self.dbname}.tbconcat'
+    def checkConcat(self):
+        tdSql.execute(f'drop database if exists {self.dbname}')
+        tdSql.execute(f'create database {self.dbname}')
+        tdSql.execute(f'use {self.dbname}')
+        tdSql.execute(f'create table if not exists {self.tbname}(ts timestamp, name varchar(20), name2 nchar(20))')
+        tdSql.execute(f'insert into {self.tbname} values(now(),"abcdefg","你好")')
+        tdSql.execute(f'insert into {self.tbname} values(now(),"abcdefgh","我好")')
+        tdSql.execute(f'insert into {self.tbname} values(now(),"abcdefg", "")')
+        tdSql.execute(f'select concat("你好",name2) from {self.tbname}')
+        tdSql.execute(f'select concat(name2,"你好") from {self.tbname}')
+        tdSql.execute(f'select concat(name2,"") from {self.tbname}')
+        tdSql.execute(f'select concat("", name2) from {self.tbname}')
+    def run(self):
+        tdLog.debug(f"start to excute {__file__}")
+        # check concat function
+        self.checkConcat()
+        tdLog.success(f"{__file__} successfully executed")
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addLinux(__file__, TDTestCase())
+tdCases.addWindows(__file__, TDTestCase())