Is there a standard approach to generating sql dynamically?

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滥情空心 2021-02-20 00:17

I want to ask how other programmers are producing Dynamic SQL strings for execution as the CommandText of a SQLCommand object.

I am producing parameterized queries conta

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  •  礼貌的吻别
    2021-02-20 01:06

    ORMs have already solved the problem of dynamic SQL generation (I prefer NHibernate/ActiveRecord). Using these tools you can create a query with an unknown number of conditions by looping across user input and generating an array of Expression objects. Then execute the built-in query methods with that custom expression set.

    List expressions = new List(userConditions.Count);
    foreach(Condition c in userConditions)
    {
        expressions.Add(Expression.Eq(c.Field, c.Value));
    }
    SomeTable[] records = SomeTable.Find(expressions);
    

    There are more 'Expression' options: non-equality, greater/less than, null/not-null, etc. The 'Condition' type I just made up, you can probably stuff your user input into a useful class.

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