SQL Statement indentation good practice [closed]

Answer 1

As most above have lined up the return column names, I find lining up tables names and conditions helps readability a lot.

SELECT 
    column1, 
    column2
FROM 
    table1
WHERE 
    column3 IN
    (
        SELECT TOP(1) 
            column4
        FROM 
            table2 INNER JOIN 
            table3 ON table2.column1 = table3.column1
    )

And for when join conditions get long.

SELECT
    Column1,
    Column2
FROM 
    Table1 JOIN 
    Table2 ON 
        Table1.Column3 = Table2.Column4 JOIN 
    Table3 ON 
        Table2.Column1 = Table3.Column1 and
        Table2.ColumnX = @x and
        Table3.ColumnY = @y
WHERE
    Condition1=xxx and
    Condition2=yyy and
    (
        Condition3=aaa or
        Condition4=bbb
    )

Answer 2

Of course, this comes down to personal preference. And if in a team setting, it's something that should be agreed upon among the members for consistency's sake. But this would be my preference:

SELECT column1, column2
FROM   table1
WHERE  column3 IN(SELECT     TOP(1) column4
                  FROM       table2
                  INNER JOIN table3 ON
                             table2.column1 = table3.column1
                 )

Answer 3

I like jalbert's form of lining up the keywords on their right. I'd also add that I like the ANDs and ORs on the left (some people put them on the right.) In addition, I like to line up my equals signs when possible.

SELECT column1, 
       column2  
  FROM table1, table2 
 WHERE table1.column1 = table2.column4 
   AND table1.col5    = "hi" 
    OR table2.myfield = 678 

Answer 4

This is a matter of taste.

This is my preference.

SELECT 
  column1
 ,column2
FROM
  table1
WHERE column3 IN (
                 SELECT TOP(1) column4
                 FROM 
                   table2
                   INNER JOIN table3
                 ON table2.column1 = table3.column1
                 )

Answer 5

This is my normal preference:

    SELECT column1
        ,column2
    FROM table1
    WHERE column3 IN (
        SELECT TOP(1) column4
        FROM table2
        INNER JOIN table3
            ON table2.column1 = table3.column1
    )

Answer 6

That's how we would do it here:

select
        COLUMN1,
        COLUMN2,
        case    when    COLUMN5 = 'X'
                        and
                        COLUMN6 = 'Y'
                then    'one'
                when    COLUMN5 in (
                                'AAA',
                                'BBB'
                        )
                then    'two'
                else    'three'
        end as COLUMN7
from
        TABLE1
where
        COLUMN2 in (
                select top(1)
                        COLUMN4
                from
                        TABLE2
                        inner join
                        TABLE3
                                on
                                        TABLE2.COLUMN1 = TABLE3.COLUMN1
                                        and
                                        TABLE2.COLUMN2
                                                between
                                                        TABLE3.COLUMN2
                                                        and
                                                        TABLE3.COLUMN3
        )

Our idea is: keep sql keywords in lower case and put all changing (and therefore "more interesting") things like table or column names in upper case. The code might look a bit "blown up" here, but it increases readability if you have complex queries with longer names (incl. schema etc.) much longer than in this example. And: indent all objects according to their "level".