具体报错：
2020-06-30 16:59:04,466 ERROR o.a.j.t.JMeterThread: Error while processing sampler: 'JDBC Request-insert'.
java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(Unknown Source) ~[?:1.8.0_251]
at java.lang.Long.parseLong(Unknown Source) ~[?:1.8.0_251]
at java.lang.Long.parseLong(Unknown Source) ~[?:1.8.0_251]
at org.apache.jmeter.functions.Random.execute(Random.java:64) ~[ApacheJMeter_functions.jar:5.3]
at org.apache.jmeter.engine.util.CompoundVariable.execute(CompoundVariable.java:135) ~[ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.engine.util.CompoundVariable.execute(CompoundVariable.java:110) ~[ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.testelement.property.FunctionProperty.getStringValue(FunctionProperty.java:100) ~[ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.modifiers.UserParameters.setValues(UserParameters.java:156) ~[ApacheJMeter_components.jar:5.3]
at org.apache.jmeter.modifiers.UserParameters.process(UserParameters.java:141) ~[ApacheJMeter_components.jar:5.3]
at org.apache.jmeter.threads.JMeterThread.runPreProcessors(JMeterThread.java:950) ~[ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:549) ~[ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:489) [ApacheJMeter_core.jar:5.3]
at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:256) [ApacheJMeter_core.jar:5.3]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_251]
解决方法：
1.查看下insert sql语句中的每个字段值是否正确，我这里是因为参数化了，但是字段参数化有问题，所以导致报错；问题如下：
2，查看下insert操作时，字段的类型是否正确，字段类型转换是否正确，否则也会报错，尤其注意date类型的参数化，时间戳比较容易出问题，
可参考：jmeter的时间戳函数使用
https://blog.csdn.net/jocleyn/article/details/83414433
我这里后来改为了：${__time(yyyy-MM-dd HH:mm:ss:SSS,time)} ，错误得以解决
