自定义SQL查询以检查GET-Request中的列

Question

I have a table with 5 columns:

Table

id----A-----B------C-----D-----E------F
1-----32----789----65----21----56-----25
2-----34----54-----45----90----34-----96
3-----10----56-----78----56----90-----45

I got a query with the 5 columns and I have to search in the database. But I don't know which column the user could want

public Response getColum(
            @QueryParam("a") short a, @QueryParam("b") short b,
            @QueryParam("c") short c,
            @QueryParam("d") short d,
            @QueryParam("e") short e) {
...

in my SQL-Query:

SELECT * FROM Table where a = ? AND b = ?

One alternativ is to check the different case, but too expensive.

How can I customize my query when I can not know which column the user could request? I don't want to build a IF-Statements, there are too many different cases.

Any ideas?

Answer 1

One approach would be instead of putting all QueryParams in the method parameters and not know which one has received values, you could just inject UriInfo object using @Context annotation and then you can have:

MultiValuedMap<String,String> params = uriInfo.getQueryParameters()

which will contain only the parameters send. then you can iterate through this map, and just dynamically create WHERE criteria which is added using a StringBuilder to the basic statement "SELECT * FROM TABLE", due to the fact that the key is the filter name (aka column name) and the value is the filter value.