像这样将冗余表连接到查询中:

select emp.empno, dept.deptno
from emp
join dept on dept.deptno = emp.deptno;

FROM TableA, TableB WHERE语法用于连接而不是FROM TableA内部连接TableB上 假设查询将以某种方式返回，而不放入ORDER BY子句，因为这是在查询工具中测试时显示的方式。

我最不喜欢的是

Using spaces when creating tables, sprocs etc. I'm fine with CamelCase or under_scores and singular or plurals and UPPERCASE or lowercase but having to refer to a table or column [with spaces], especially if [ it is oddly spaced] (yes, I've run into this) really irritates me. Denormalized data. A table doesn't have to be perfectly normalized, but when I run into a table of employees that has information about their current evaluation score or their primary anything, it tells me that I will probably need to make a separate table at some point and then try to keep them synced. I will normalize the data first and then if I see a place where denormalization helps, I'll consider it. Overuse of either views or cursors. Views have a purpose, but when each table is wrapped in a view it's too much. I've had to use cursors a few times, but generally you can use other mechanisms for this. Access. Can a program be an anti-pattern? We have SQL Server at my work, but a number of people use access due to it's availabilty, "ease of use" and "friendliness" to non-technical users. There is too much here to go into, but if you've been in a similar environment, you know.

我一直对大多数程序员倾向于在数据访问层混合他们的ui逻辑感到失望:

SELECT
    FirstName + ' ' + LastName as "Full Name",
    case UserRole
        when 2 then "Admin"
        when 1 then "Moderator"
        else "User"
    end as "User's Role",
    case SignedIn
        when 0 then "Logged in"
        else "Logged out"
    end as "User signed in?",
    Convert(varchar(100), LastSignOn, 101) as "Last Sign On",
    DateDiff('d', LastSignOn, getDate()) as "Days since last sign on",
    AddrLine1 + ' ' + AddrLine2 + ' ' + AddrLine3 + ' ' +
        City + ', ' + State + ' ' + Zip as "Address",
    'XXX-XX-' + Substring(
        Convert(varchar(9), SSN), 6, 4) as "Social Security #"
FROM Users

通常，程序员这样做是因为他们想要将数据集直接绑定到一个网格上，而且在服务器端使用SQL Server格式比在客户端使用SQL Server格式更方便。

像上面所示的查询是非常脆弱的，因为它们将数据层与UI层紧密耦合在一起。最重要的是，这种编程风格彻底阻止了存储过程的可重用性。

过度使用临时表和游标。

使用SP作为存储过程名称的前缀，因为它将首先在系统过程位置中搜索，而不是自定义过程。