Using custom converter for JOOQ's DSL.val()

问题

In my application, a piece of content is identified using java.util.UUID. While storing information in the database, the corresponding MySQL data type that I am using is BINARY(16). The default JDBC data type for BINARY is byte[]. So I have a custom org.jooq.Converter to translate between UUID and byte[].

I have a use-case in which I need to copy a record from a table into the same table but copy only certain columns and not all. In the original question I had posted here, The following was the solution

public void copy(UUID source, UUID target) {
    jooq.insertInto(PERSON)
            .columns(PERSON.ID, PERSON.FNAME, PERSON.LNAME)
            .select(select(val(target), PERSON.FNAME, PERSON.LNAME)
                   .from(PERSON)
                   .where(PERSON.ID.eq(source)))
            .execute();
} 

But executing this piece of code led to an exception

Data truncation: Data too long for column 'id' at row 1

I figured out that DSL.val() was not using the custom converter I had in place for converting UUID to byte[]. How can I force the DSL.val() function to use the custom converter?

回答1:

Solution: Use DSL.val(java.lang.Object value, DataType<T> type) instead of just DSL.val(java.lang.Object value)

Following is the updated code snippet

public void copy(UUID source, UUID target) {
    DataType<UUID> uuidType = SQLDataType.BINARY
                                .asConvertedDataType(new UuidBinaryConverter());
    jooq.insertInto(PERSON)
            .columns(PERSON.ID, PERSON.FNAME, PERSON.LNAME)
            .select(select(val(target, uuidType), PERSON.FNAME, PERSON.LNAME)
                   .from(PERSON)
                   .where(PERSON.ID.eq(source)))
            .execute();
} 

来源：https://stackoverflow.com/questions/50741895/using-custom-converter-for-jooqs-dsl-val