jooq getValue（String fieldName）不同表中具有相同名称的列

Question

SQL:

SELECT tblA.hostname, tblB.hostname FROM tblA, tblB ...

When trying to get the hostname from each table, it does not work. For example,

String clientHostname = (String) result.getValue("tblA.hostname"); 
String serverHostname = (String) result.getValue("tblB.hostname");

Execution exception: [IllegalArgumentException: Field (tblA.hostname) is not contained in Row (hostname, hostname)]

Then, another attempt to correct the issue with:

String clientHostname = (String) result.getValue("hostname"); 
String serverHostname = (String) result.getValue("hostname");

This does not return the desired behavior where clientHostname = tblA.hostname and serverHostname = tblB.hostname, it just returns tblA.hostname for both.

How do I get the values for both columns?

Answer 1

Have you tried this?

"SELECT tblA.hostname , tblB.hostname FROM tblA, tblB ..."

String clientHostname = (String) result.getValue("tblAhostname"); String serverHostname = (String) result.getValue("tblBhostname");

Answer 2

Apart from explicitly renaming columns as Erik suggested , you can access qualified column names like this:

String clientHostname = result.getValue(field(name("tblA", "hostname"), String.class)); 
String serverHostname = result.getValue(field(name("tblB", "hostname"), String.class));

This solution makes use of:

• DSL.field(Name, Class) to construct a "plain SQL" field
• DSL.name(String...) to construct an identifier

More information about this API can be found in the manual:

• http://www.jooq.org/doc/latest/manual/sql-building/plain-sql

Note, there's also a pending feature request #4578 to allow for using the API the way you have intended.