1、SQLSERVER
建立使用者
sp_addlogin @loginame = N'commonuser'
  , @passwd = N'Admin123'
  , @defdb = N'master'
  , @sid = null
  , @encryptopt = null
GO
EXEC sp_addsrvrolemember N'commonuser', N'sysadmin'

刪除使用者
sp_droplogin @loginame = N'commonuser'
GO

檢視資料庫版本：
select @@version

2、mysql
建立使用者

create user

create user [email protected]'localhost' identified by 'Admin123';
grant all on *.* to [email protected]'localhost' identified by 'Admin123';

3、ORACLE

刪除使用者：

declare
  v_cnt number;
  sqlstr varchar2(512);
begin
  sqlstr:='drop user COMMONUSER cascade';
  execute immediate sqlstr;
end;
/

建立使用者：

declare
  v_cnt number;
  sqlstr varchar2(512);
begin
  select count(USERNAME) into v_cnt from dba_users where username='COMMONUSER';
  if v_cnt=0 then
    sqlstr:='create user COMMONUSER identified by "******" default tablespace SYSTEM temporary tablespace TEMP quota unlimited on SYSTEM';
    execute immediate sqlstr;
    sqlstr:='grant dba to COMMONUSER';
    execute immediate sqlstr;
  end if;
end;