使用JDBC连接器在Java中的一个查询中进行多次选择

Question

I try to multiple select in java. I have two string "name" and "artist" i want to select them both in one query even if one of them is null .

I did something like that :

if ( !nameIsEmpty && !artisIsEmpty )
{
    rst = stmt.executeQuery("SELECT * FROM school.product_table where name=" + "'" + name + "'  and artist=" + "'" + artist + "'");
}
else if ( nameIsEmpty && !artisIsEmpty )
{
    rst = stmt.executeQuery("SELECT * FROM school.product_table where  artist=" + "'" + artist + "'");
}
else if ( !nameIsEmpty && artisIsEmpty )
{
    rst = stmt.executeQuery("SELECT * FROM school.product_table where  name=" + "'" + name + "'");
}
else
{
    productIsEmpty = true;
}

I think its not the best way to do this. And I hope there is a easy way to this in one query. Thanks in advance.

Answer 1

SELECT * FROM school.product_table where name in(name.null) and artist in (name,null)

Along with matching the records with name and artist, it will also return results with name=null and artist, artist=null and name, null and null.

If you want to skip both null results try this -

SELECT * FROM school.product_table where name in(name.null) and artist in (name,null) and !(artist=null && name=null)