执行 xp_cmdshell bcp 语法

我似乎找不到正确的语法来使用 sql server management studio 中的 exec xp_cmdshell bcp 导出具有列名称的数据。我尝试了以下变体

EXEC xp_cmdshell bcp "select "a_id","b_id","c_id" union select a_id,b_id,c_id from  tablename out 
"\\network_path\a.txt" -c -Uusername -Ppassword -Sservername"

And

EXEC xp_cmdshell bcp 'select 'a_id','b_id','c_id' union select a_id,b_id,c_id from  tablename out 
'\\network_path\a.txt' -c -Uusername -Ppassword -Sservername'

And

EXEC xp_cmdshell bcp 'select "a_id","b_id","c_id" union select a_id,b_id,c_id from  tablename out 
"\\network_path\a.txt" -c -Uusername -Ppassword -Sservername'

And

EXEC xp_cmdshell bcp "select 'a_id','b_id','c_id' union select a_id,b_id,c_id from  tablename out 
'\\network_path\a.txt' -c -Uusername -Ppassword -Sservername"

我已成功使用以下命令导出表，但我还需要列名。

bcp tablename out "\\network_path\a_test.txt" -c -Uusername -Ppassword -Sservername'

好吧，您实际上需要对标题行进行排序，以便它显示在顶部。这应该可以处理它

EXEC xp_cmdshell 'bcp "select * from (select ''a_id'' as a_id,''b_id'' as b_id,''c_id'' as c_id union select a_id,b_id,c_id from tablename)q order by case a_id when ''a_id'' then 0 ELSE 1 END" queryout "\\networkpath\a.txt" -c -Uusername -Ppassword -Sservername -ddatabasename'