title: SQL Server login failed for user error 18456
body: <p>I installed docker and I run this command in windows</p>
  
  <pre><code>docker run -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=MyComplexPassword!234" -e "MSSQL_PID=sa" --cap-add SYS_PTRACE -p 1404:1433 -d microsoft/mssql-server-linux
  </code></pre>
  
  <p>then I donwloaded SQL Server 2012 and in the server name I write localhost and in login : sa
  password as you can see in the installation command.</p>
  
  <p>but I get the error SQL Server login failed for user.</p>
  
  <p><a href="https://i.stack.imgur.com/WCoE0.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WCoE0.jpg" alt="enter image description here"></a></p>
  
  <p>What is wrong?</p>