在休眠中更新列

Question

我正在尝试通过串联相同的列值来更新列。     即，我正在尝试编写类似“ 更新t_user设置名称= concat（name，“ 1-12-2016”），其中projectID = 212 ”的查询。为此，我尝试了所有这些情况。

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CriteriaBuilder builder = session.getCriteriaBuilder();
CriteriaUpdate<AdminUser> update = builder.createCriteriaUpdate(AdminUser.class);
Root<AdminUser> root = update.from(AdminUser.class);
update.set(root.get("enabled"), false);
update.set("userName", builder.concat(unameTimestamp, root.get("userName")));
update.where(builder.equal(root.get("projectID"), userID));
session.createQuery(update).executeUpdate();
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CriteriaBuilder builder = session.getCriteriaBuilder();
CriteriaUpdate<AdminUser> update = builder.createCriteriaUpdate(AdminUser.class);
Root<AdminUser> root = update.from(AdminUser.class);
update.set(root.get("enabled"), false);
Expression<String> exp = builder.concat(unameTimestamp, root.get("userName"));
update.set("userName", exp);
update.where(builder.equal(root.get("projectID"), userID));
session.createQuery(update).executeUpdate();
tx.commit()
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when ever I tried this I am getting 

java.lang.ClassCastException: org.hibernate.query.criteria.internal.expression.ConcatExpression cannot be cast to java.lang.String 

Or if I wrote like this

update.set(root.get("userName"), builder.concat(unameTimestamp, root.get("userName"))); I am getting compilation error as 

The method set(Path<Expression<String>>, Expression<String>) is ambiguous for the type CriteriaUpdate<AdminUser>

Please can somebody help me.