SQL formatting standards

Question

In my last job, we worked on a very database-heavy application, and I developed some formatting standards so that we would all write SQL with a common layout. We also developed coding standards, but these are more platform-specific so I'll not go into them here.

I'm interested to know what other people use for SQL formatting standards. Unlike most other coding environments, I haven't found much of a consensus online for them.

To cover the main query types:

select
    ST.ColumnName1,
    JT.ColumnName2,
    SJT.ColumnName3
from 
    SourceTable ST
inner join JoinTable JT
    on JT.SourceTableID = ST.SourceTableID
inner join SecondJoinTable SJT
    on ST.SourceTableID = SJT.SourceTableID
    and JT.Column3 = SJT.Column4
where
    ST.SourceTableID = X
    and JT.ColumnName3 = Y

There was some disagreement about line feeds after select, from and where. The intention on the select line is to allow other operators such as "top X" without altering the layout. Following on from that, simply keeping a consistent line feed after the key query elements seemed to result in a good level of readability.

Dropping the linefeed after the from and where would be an understandable revision. However, in queries such as the update below, we see that the line feed after the where gives us good column alignment. Similarly, a linefeed after group by or order by keeps our column layouts clear and easy to read.

update
    TargetTable
set
    ColumnName1 = @value,
    ColumnName2 = @value2
where
    Condition1 = @test

Finally, an insert:

insert into TargetTable (
    ColumnName1,
    ColumnName2,
    ColumnName3
) values (
    @value1,
    @value2,
    @value3
)

For the most part, these don't deviate that far from the way MS SQL Server Managements Studio / query analyser write out SQL, however they do differ.

I look forward to seeing whether there is any consensus in the Stack Overflow community on this topic. I'm constantly amazed how many developers can follow standard formatting for other languages and suddenly go so random when hitting SQL.

Answer 1

Late answer, but hopefully useful.

My experience working as part of the larger development team is that you can go ahead and define any standards you like, but the problem is actually enforcing these or making it very easy for developers to implement.

As developers we sometimes create something that works and then say “I’ll format it later”, but that later never comes.

Initially, we used SQL Prompt (it was great) for this, but then switched to ApexSQL Refactor, because it’s a free tool.