Underlying data writing for conditional queries

At the underlying layer of a query written a few days ago, seven parameters, four field parameters, and three paging parameters were used.
A write parameter query is a query that meets the query conditions. In the previous console, the query is performed based on the selected operation.
When writing data layers, you must query them according to the conditions.
When writing parameters for SQL statements, add the following judgment:
If the field is a string:

If (sparam! = NULL & sparam! = "")
{
Sbmsg. appand ("and database field =" + sparam + "");
}

If the database field is int type:

If (iparam> 0)
{
Sbmsg. appand ("and database field =" + iparam + "");
}

That is to say, during data query, these SQL statements can be executed when the value assigned to the parameter meets these conditions.