Java，CriteriaBuilder，使用可选参数“ where”

2024-05-21 • 问答

我必须重写一些代码，但是无法在Internet上找到正确的信息。原始部分如下所示：

String query = "select * from sublog_type_map_v where 1 = 1";
if (responsibleGroupId != null && responsibleGroupId.length() != 0 && !responsibleGroupId.equals("0")) {
    query += " and responsible_group_id = " + responsibleGroupId;
}
if (categoryId != null && categoryId.length() != 0 && !categoryId.equals("0")) {
    query += " and category_id = " + categoryId;
}
if (typeId != null && typeId.length() != 0 && !typeId.equals("0")) {
    query += " and type_id = " + typeId;
}
if (subtypeId != null && subtypeId.length() != 0 && !subtypeId.equals("0")) {
    query += " and subtype_id = " + subtypeId;
}

我已经进行了这段代码：

CriteriaBuilder builder = entityManager.getcriteriaBuilder();
CriteriaQuery<SublogTypeMapV> query = builder.createQuery(SublogTypeMapV.class);
Root<SublogTypeMapV> root = query.from(SublogTypeMapV.class);
query.select(root).where(builder.equal(root.get("responsibleGroupId"),responsibleGroupId));

但是，使用“ if”表达式以及其他三个参数（稍后将添加）将其视为“可选”。我不知道该怎么做，有人可以帮我吗？

CriteriaBuilder builder = entityManager.getCriteriaBuilder(); CriteriaQuery<SublogTypeMapV> query = builder.createQuery(SublogTypeMapV.class); Root<SublogTypeMapV> root = query.from(SublogTypeMapV.class); query = query.select(root); if("some boolean expression") { query = query.where(builder.equal(root.get("responsibleGroupId"),responsibleGroupId)); }

Java，CriteriaBuilder，使用可选参数“ where”

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