SQL statement issues

F get domain contrast is a formatting function (should be written by yourself), the first parameter (arg prod spec id) according to the second parameter (120) formatting and return the result to the v bill code, according to the function naming method, the above ** should be the standard format for getting the date.

1: select * from a table where b is null or c is null or d is null; (If it's an empty string b=.)'' or c='' or d='')

2: select * from a table where e<>f+g;

For question three. There can be no fields or no fields in a table, and this table structure cannot be set. You can only say that the current field is empty or non-empty.

select * from a table where h=i+j or (h is null and i is null and j is null);

Explanation If the previous equation is true, then requirement 1 is satisfied, because h is not empty then i+j=h ;

This is followed by h is null when h is null, and i is null and j is null must be null;

f get domain contrast is this a stored procedure?

arg prod spec id, 120 corresponds to the parameter.

You'll have to look at f get domain contrast to see what 120 does!

1, select name, sum(grade) as total score from data table name group by name.

3.select count(*)as number of people, course name from data table name group by course name.

3.select * from ( select count(*)as number of people ,course name,course id from data table name group by course name,course id) where number of people》30

Other analogies.

At least post the structure of the table that is used.。。