MybatisPlus Caused by: org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew != null and ew.sqlSet != null'. Cause

报错信息：

org.mybatis.spring.MyBatisSystemException: null
    at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:97)
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:439)
...

Caused by: org.apache.ibatis.builder.BuilderException: Error evaluating expression 'ew != null and ew.sqlSet != null'. Cause: org.apache.ibatis.ognl.OgnlException: sqlSet [com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: can not use this method for "getSqlSet"]
    at org.apache.ibatis.scripting.xmltags.OgnlCache.getValue(OgnlCache.java:48)
    at org.apache.ibatis.scripting.xmltags.ExpressionEvaluator.evaluateBoolean(ExpressionEvaluator.java:32)
    at org.apache.ibatis.scripting.xmltags.IfSqlNode.apply(IfSqlNode.java:34)
    at org.apache.ibatis.scripting.xmltags.MixedSqlNode.lambda$apply$0(MixedSqlNode.java:32)
...

Caused by: org.apache.ibatis.ognl.OgnlException: sqlSet
Caused by: com.baomidou.mybatisplus.core.exceptions.MybatisPlusException: can not use this method for "getSqlSet"
    at com.baomidou.mybatisplus.core.toolkit.ExceptionUtils.mpe(ExceptionUtils.java:49)
    at com.baomidou.mybatisplus.extension.conditions.update.LambdaUpdateChainWrapper.getSqlSet(LambdaUpdateChainWrapper.java:63)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at org.apache.ibatis.ognl.OgnlRuntime.invokeMethodInsideSandbox(OgnlRuntime.java:1245)
...

报错原因：

//serviceImpl代码
baseMapper.update(this.lambdaUpdate().eq(Order::getId, order.getId()).set(Order::getStatus, Order.Status.STORE_SUBMIT.getCode())
        .set(Order::getUpdatedId, sysUser.getId()).set(Order::getUpdatedTime, LocalDateTime.now()))

//注意this.lambdaUpdate()的只用方法，该方法返回对象LambdaUpdateChainWrapper<T>，虽然该对象也是Wrapper<T>的子类，所以下面写法不会编译报错，但是执行时会报错，LambdaUpdateChainWrapper<T>对象不能直接用baseMapper对象去执行
//this.update()方法与this.lambdaUpdate()相同

//this.lambdaUpdate()的正确用法如下（最后直接调用.update()方法去执行修改sql，或调.remove()方法执行删除sql）

this.lambdaUpdate().eq(Order::getId, order.getId()).set(Order::getStatus, Order.Status.STORE_SUBMIT.getCode())

.set(Order::getUpdatedId, sysUser.getId()).set(Order::getUpdatedTime, LocalDateTime.now()).update()

//同样this.lambdaQuery()的正确用法是调.list()方法执行查询sql，代码如下
//this.query()方法与this.lambdaQuery()相同

this.lambdaQuery().eq(Order::getId, order.getId()).list();

 解决方法：使用正确的调用方式

//baseMapper.selectList()的正确调用方式如下

baseMapper.selectList(Wrappers.lambdaQuery(Order.class).eq(Order::getId, "id"));

baseMapper.selectList(new LambdaQueryWrapper<Order>().eq(Order::getId, "id"));

//baseMapper.update(）的正确调用方式如下

baseMapper.update(Wrappers.lambdaUpdate(Order.class).eq(Order::getId, "id").set(Order::getStatus, 1));

baseMapper.update(new LambdaUpdateWrapper<Order>().eq(Order::getId, "id").set(Order::getStatus, 1));

希望对你有帮助