Mysql Slick 3.0(scala)查询不';在多次运行之前不要返回数据(我认为)
所以我对数据库、slick和scala非常(非常)陌生,所以我使用了他们的文档中的示例代码 我的问题是,出于某种原因,我必须在查询返回数据之前运行多次。在返回结果之前,我必须重新运行它至少3-4次。我使用for循环来重新运行查询,它们也不一定每次都给出完全相同的结果 要创建两个表,请执行以下操作:Mysql Slick 3.0(scala)查询不';在多次运行之前不要返回数据(我认为),mysql,scala,slick,slick-3.0,Mysql,Scala,Slick,Slick 3.0,所以我对数据库、slick和scala非常(非常)陌生,所以我使用了他们的文档中的示例代码 我的问题是,出于某种原因,我必须在查询返回数据之前运行多次。在返回结果之前,我必须重新运行它至少3-4次。我使用for循环来重新运行查询,它们也不一定每次都给出完全相同的结果 要创建两个表,请执行以下操作: class Patients(tag: Tag) extends Table[(String, String, Int, String)](tag, "Patientss") { def
class Patients(tag: Tag) extends Table[(String, String, Int, String)](tag, "Patientss") {
def PID = column[String]("Patient Id", O.PrimaryKey)
def Gender = column[String]("Gender")
def Age = column[Int]("Age")
def Ethnicity = column[String]("Ethnicity")
def * = (PID, Gender, Age, Ethnicity)
}
val patientsss = TableQuery[Patients]
class DrugEffect(tag: Tag) extends Table[(String, String, Double)](tag, "DrugEffectss") {
def DrugID = column[String]("Drug ID", O.PrimaryKey)
def PatientID = column[String]("Patient_ID")
def DrugEffectssss = column[Double]("Drug Effect")
def * = (DrugID, PatientID, DrugEffectssss)
def Patient = foreignKey("Patient_FK", PatientID, patientsss)(_.PID)}
val d_effects = TableQuery[DrugEffect]
然后,我使用
val create_empty = DBIO.seq((patientsss.schema ++ d_effects.schema).create)
val setup_1 = db.run(create_empty)
我有两个文本文件中的实际数据,我通过使用缓冲读取器来解析它们。
我将所有药物ID存储在一个列表中,该列表创造性地命名为DrugIds
然后,我开始按以下方式填写表格
我首先填写患者表:
while (switch != 1) {
val Patient = CurPatient.split("\\s+")
if (Patient(2).toUpperCase() == "NA" || (Patient(2).toFloat % 1 != 0))
age = -1
else age = Patient(2).toInt
val insertPatient: DBIO[Option[Int]] = patientsss ++= Seq(
(Patient(0), Patient(1), age, Patient(3))
)
var future = db.run(insertPatient)
CurPatient = PatientReader.readLine()
if (CurPatient == null)
switch = 1 //switch to 1
}
对于DrugEffects表,我执行以下操作:
while (switch != 1) {
val Effect = CurEffect.split("\\s+")
for (i <- 1 until DrugIds.size - 1) {
if (Effect(i).toUpperCase() == "NA")
d_ef = -1.00
else d_ef = (Effect(i).toFloat).asInstanceOf[Double]
val insertEffect: DBIO[Option[Int]] = d_effects ++= Seq(
(DrugIds(i), Effect(0), d_ef)
)
var future2 = db.run(insertEffect)
}
CurEffect = EffectReader.readLine()
if (CurEffect == null)
switch = 1
}
如果我运行一个更复杂的查询,我得到的数据与查询的参数是准确的,但同样的问题也会出现,即结果要么重复,要么不存在,要么不完整(当我多次重新运行查询时)
如果可以的话,请像我5岁一样解释,或者给我指一个可以帮助我解决这些问题的资源
编辑:
bjfletcher的回答有效(谢谢!),但现在我有另一个问题:
每隔一段时间,代码就会失败,并出现以下错误:
Exception in thread "main" org.h2.jdbc.JdbcSQLException: Table "Patientss" not found; SQL statement:
insert into "Patientss" ("Patient Id","Gender","Age","Ethnicity") values (?,?,?,?) [42102-162]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:329)
at org.h2.message.DbException.get(DbException.java:169)
at org.h2.message.DbException.get(DbException.java:146)
at org.h2.command.Parser.readTableOrView(Parser.java:4758)
at org.h2.command.Parser.readTableOrView(Parser.java:4736)
at org.h2.command.Parser.parseInsert(Parser.java:954)
at org.h2.command.Parser.parsePrepared(Parser.java:375)
at org.h2.command.Parser.parse(Parser.java:279)
at org.h2.command.Parser.parse(Parser.java:251)
at org.h2.command.Parser.prepareCommand(Parser.java:217)
at org.h2.engine.Session.prepareLocal(Session.java:415)
at org.h2.engine.Session.prepareCommand(Session.java:364)
at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1121)
at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:71)
at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:267)
at slick.jdbc.JdbcBackend$SessionDef$class.prepareStatement(JdbcBackend.scala:252)
at slick.jdbc.JdbcBackend$BaseSession.prepareStatement(JdbcBackend.scala:386)
at slick.jdbc.JdbcBackend$SessionDef$class.withPreparedStatement(JdbcBackend.scala:301)
at slick.jdbc.JdbcBackend$BaseSession.withPreparedStatement(JdbcBackend.scala:386)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.preparedInsert(JdbcInsertInvokerComponent.scala:177)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker$$anonfun$internalInsertAll$1.apply(JdbcInsertInvokerComponent.scala:201)
at slick.jdbc.JdbcBackend$BaseSession.withTransaction(JdbcBackend.scala:422)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.internalInsertAll(JdbcInsertInvokerComponent.scala:198)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.insertAll(JdbcInsertInvokerComponent.scala:194)
at slick.driver.JdbcInsertInvokerComponent$InsertInvokerDef$class.$plus$plus$eq(JdbcInsertInvokerComponent.scala:73)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.$plus$plus$eq(JdbcInsertInvokerComponent.scala:152)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anonfun$$plus$plus$eq$1.apply(JdbcActionComponent.scala:459)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anonfun$$plus$plus$eq$1.apply(JdbcActionComponent.scala:459)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anon$8.run(JdbcActionComponent.scala:449)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anon$8.run(JdbcActionComponent.scala:447)
at slick.backend.DatabaseComponent$DatabaseDef$$anon$2.liftedTree1$1(DatabaseComponent.scala:231)
at slick.backend.DatabaseComponent$DatabaseDef$$anon$2.run(DatabaseComponent.scala:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
线程“main”org.h2.jdbc.JdbcSQLException中的异常:未找到表“Patientss”;SQL语句:
在“患者”中插入(“患者Id”、“性别”、“年龄”、“种族”)值(?、、?、?)[42102-162]
位于org.h2.message.DbException.getJdbcSQLException(DbException.java:329)
位于org.h2.message.DbException.get(DbException.java:169)
位于org.h2.message.DbException.get(DbException.java:146)
位于org.h2.command.Parser.readTableOrView(Parser.java:4758)
位于org.h2.command.Parser.readTableOrView(Parser.java:4736)
位于org.h2.command.Parser.parseInsert(Parser.java:954)
位于org.h2.command.Parser.parsePrepared(Parser.java:375)
位于org.h2.command.Parser.parse(Parser.java:279)
位于org.h2.command.Parser.parse(Parser.java:251)
位于org.h2.command.Parser.prepareCommand(Parser.java:217)
位于org.h2.engine.Session.prepareLocal(Session.java:415)
位于org.h2.engine.Session.prepareCommand(Session.java:364)
位于org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1121)
在org.h2.jdbc.JdbcPreparedStatement。(JdbcPreparedStatement.java:71)
位于org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:267)
在slick.jdbc.jdbcbbackend$SessionDef$class.prepareStatement(jdbcbbackend.scala:252)
在slick.jdbc.JdbcBackend$BaseSession.prepareStatement(JdbcBackend.scala:386)上
在slick.jdbc.JdbcBackend$SessionDef$class.withPreparedStatement(JdbcBackend.scala:301)上
在slick.jdbc.JdbcBackend$BaseSession.withPreparedStatement(JdbcBackend.scala:386)上
在slick.driver.jdbcinertinvokercomponent$BaseInsertInvoker.preparedInsert(jdbcinertinvokercomponent.scala:177)
在slick.driver.jdbinsertinvokercomponent$BaseInsertInvoker$$anonfun$internalInsertAll$1.apply(jdbinsertinvokercomponent.scala:201)
在slick.jdbc.JdbcBackend$BaseSession.withTransaction上(JdbcBackend.scala:422)
在slick.driver.jdbcinertinvokercomponent$BaseInsertInvoker.internalInsertAll(jdbcinertinvokercomponent.scala:198)
在slick.driver.jdbcinertinvokercomponent$BaseInsertInvoker.insertAll(jdbcinertinvokercomponent.scala:194)
在slick.driver.jdbcinertinvokercomponent$InsertInvokerDef$class.$plus$plus$eq(jdbcinertinvokercomponent.scala:73)
在slick.driver.jdbcinertinvokercomponent$BaseInsertInvoker.$plus$plus$eq(jdbcinertinvokercomponent.scala:152)
在slick.driver.jdbActionComponent$insertActionComposer impl$$anonfun$$plus$plus$eq$1.apply(jdbActionComponent.scala:459)
在slick.driver.jdbActionComponent$insertActionComposer impl$$anonfun$$plus$plus$eq$1.apply(jdbActionComponent.scala:459)
在slick.driver.jdbActionComponent$insertActionComposer impl$$anon$8.run(jdbActionComponent.scala:449)
在slick.driver.jdbActionComponent$insertActionComposer impl$$anon$8.run(jdbActionComponent.scala:447)
在slick.backend.DatabaseComponent$DatabaseDef$$anon$2.liftedTree1$1(DatabaseComponent.scala:231)
在slick.backend.DatabaseComponent$DatabaseDef$$anon$2.run(DatabaseComponent.scala:231)
位于java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
位于java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
运行(Thread.java:745)
不是一直都会发生,但经常发生,我不知道这意味着什么所有DB调用都会立即返回到您的
Futures
,即使它们尚未完成操作。这是异步的,不是同步的
您可以通过以下两种方式之一更改代码以适应未来
:
wait.result
,在该点等待,直到它们完成,例如:wait.result(DB.run(insertEffect)、Duration.Inf)
.map
(或.flatMap
,如果您从内部使用另一个未来
),以及您希望在DB操作完成时运行的代码。例如:db.run(insertEffect).map(=>…dostuff…)
查看另一个有关异常的堆栈溢出,并了解其原因。所有DB调用都将立即返回到您的
Futures
,即使它们尚未完成操作。这是异步的,不是同步的
您可以通过以下两种方式之一更改代码以适应未来
:
wait.result
,在该点等待,直到它们完成,例如:wait.result(DB.run(insertEffect)、Duration.Inf)
java.util.concurrent.RejectedExecutionException: Task slick.backend.DatabaseComponent$DatabaseDef$$anon$3@47089c2c rejected from java.util.concurrent.ThreadPoolExecutor@6453123[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 215]
at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2048)
at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:821)
at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1372)
at scala.concurrent.impl.ExecutionContextImpl$$anon$1.execute(ExecutionContextImpl.scala:136)
at slick.backend.DatabaseComponent$DatabaseDef$class.scheduleSynchronousStreaming(DatabaseComponent.scala:253)
at slick.jdbc.JdbcBackend$DatabaseDef.scheduleSynchronousStreaming(JdbcBackend.scala:38)
at slick.backend.DatabaseComponent$BasicStreamingActionContext.restartStreaming(DatabaseComponent.scala:516)
at slick.backend.DatabaseComponent$BasicStreamingActionContext.request(DatabaseComponent.scala:531)
at slick.backend.DatabasePublisher$$anon$3$$anonfun$onNext$2.apply(DatabasePublisher.scala:50)
at slick.backend.DatabasePublisher$$anon$3$$anonfun$onNext$2.apply(DatabasePublisher.scala:49)
at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)
at scala.concurrent.impl.ExecutionContextImpl$AdaptedForkJoinTask.exec(ExecutionContextImpl.scala:121)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.pollAndExecAll(ForkJoinPool.java:1253)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1346)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Exception in thread "main" org.h2.jdbc.JdbcSQLException: Table "Patientss" not found; SQL statement:
insert into "Patientss" ("Patient Id","Gender","Age","Ethnicity") values (?,?,?,?) [42102-162]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:329)
at org.h2.message.DbException.get(DbException.java:169)
at org.h2.message.DbException.get(DbException.java:146)
at org.h2.command.Parser.readTableOrView(Parser.java:4758)
at org.h2.command.Parser.readTableOrView(Parser.java:4736)
at org.h2.command.Parser.parseInsert(Parser.java:954)
at org.h2.command.Parser.parsePrepared(Parser.java:375)
at org.h2.command.Parser.parse(Parser.java:279)
at org.h2.command.Parser.parse(Parser.java:251)
at org.h2.command.Parser.prepareCommand(Parser.java:217)
at org.h2.engine.Session.prepareLocal(Session.java:415)
at org.h2.engine.Session.prepareCommand(Session.java:364)
at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1121)
at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:71)
at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:267)
at slick.jdbc.JdbcBackend$SessionDef$class.prepareStatement(JdbcBackend.scala:252)
at slick.jdbc.JdbcBackend$BaseSession.prepareStatement(JdbcBackend.scala:386)
at slick.jdbc.JdbcBackend$SessionDef$class.withPreparedStatement(JdbcBackend.scala:301)
at slick.jdbc.JdbcBackend$BaseSession.withPreparedStatement(JdbcBackend.scala:386)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.preparedInsert(JdbcInsertInvokerComponent.scala:177)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker$$anonfun$internalInsertAll$1.apply(JdbcInsertInvokerComponent.scala:201)
at slick.jdbc.JdbcBackend$BaseSession.withTransaction(JdbcBackend.scala:422)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.internalInsertAll(JdbcInsertInvokerComponent.scala:198)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.insertAll(JdbcInsertInvokerComponent.scala:194)
at slick.driver.JdbcInsertInvokerComponent$InsertInvokerDef$class.$plus$plus$eq(JdbcInsertInvokerComponent.scala:73)
at slick.driver.JdbcInsertInvokerComponent$BaseInsertInvoker.$plus$plus$eq(JdbcInsertInvokerComponent.scala:152)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anonfun$$plus$plus$eq$1.apply(JdbcActionComponent.scala:459)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anonfun$$plus$plus$eq$1.apply(JdbcActionComponent.scala:459)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anon$8.run(JdbcActionComponent.scala:449)
at slick.driver.JdbcActionComponent$InsertActionComposerImpl$$anon$8.run(JdbcActionComponent.scala:447)
at slick.backend.DatabaseComponent$DatabaseDef$$anon$2.liftedTree1$1(DatabaseComponent.scala:231)
at slick.backend.DatabaseComponent$DatabaseDef$$anon$2.run(DatabaseComponent.scala:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)