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问题描述
我正在使用带有 SpringData 的 QueryDSL.我有表说，Employee，我创建了实体类说，EmployeeEntity我写了以下 service 方法
I am using QueryDSL with SpringData.
I have Table say, Employee and I have created entity class say, EmployeeEntity
I have written following service method
public EmployeeEntity getEmployees(String firstName, String lastName)
{
QEmployeeEntity employee = QEmployeeEntity.employeeEntity;
BooleanExpression query = null;
if(firstName != null)
{
query = employee.firstName.eq(firstName);
}
if(lastName != null)
{
query = query.and(employee.lastName.eq(lastName)); // NPException if firstName is null as query will be NULL
}
return empployeeDAO.findAll(query);
}
如上所述，我注释了 NPException.如何使用 Spring Data 将 QueryDSL 用于 QueryDSL 中的可选参数?
As in above I commented the NPException. How to use QueryDSL for optional Parameters in QueryDSL using Spring Data?
谢谢你:)
推荐答案
BooleanBuilder 可以用作布尔表达式的动态构建器:
BooleanBuilder can be used as a dynamic builder for boolean expressions:
public EmployeeEntity getEmployees(String firstName, String lastName) {
QEmployeeEntity employee = QEmployeeEntity.employeeEntity;
BooleanBuilder where = new BooleanBuilder();
if (firstName != null) {
where.and(employee.firstName.eq(firstName));
}
if (lastName != null) {
where.and(employee.lastName.eq(lastName));
}
return empployeeDAO.findAll(where);
}
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