如何调用存储过程并在 Slick 中获取 return 值（使用 Scala）
How to call a stored procedure and get return value in Slick (using Scala)
我正在尝试从 Slick 3.0（在 Play Framework 中）调用存储过程。我一遍又一遍地查看文档，但不幸的是 plain SQL docs at Typesafe 从未显示调用存储过程。
看起来很简单的事情导致了一个典型的晦涩难懂的 Scala 错误消息：
val f = Try {
val call: DBIO[Int] = sqlu"?=call app_glimpulse_invitation_pkg.n_send_invitation(${i.token}, ${i.recipientAccountId.getOrElse(None)}, ${i.email}, ${i.phoneNumber}, ${requestType})"
val result: Future[Int] = db.run(call)
val r = Await.result(result, Duration.Inf) // should only return one; use .seq.count(_.id != null)) to validate
val z = result.value.get.get // should return the stored procedure return value...?
}
以上代码导致此编译器错误：
[error] /Users/zbeckman/Projects/Glimpulse/Server-2/project/glimpulse-server/app/controllers/GPInviteService/GPInviteService.scala:120: could not find implicit value for parameter e: slick.jdbc.SetParameter[Product with Serializable]
[error] val call: DBIO[Int] = sqlu"?=call app_glimpulse_invitation_pkg.n_send_invitation(${i.token}, ${i.recipientAccountId.getOrElse(None)}, ${i.email}, ${i.phoneNumber}, ${requestType})"
[error] ^
如果我使用纯硬编码的调用语句（删除所有 ${i.xyz} 引用，我可以编译它...但是，我收到运行时错误报告 Update statements should not return a result set.
这导致我将语句更改为常规 sql 调用：
val call: DBIO[Seq[(Int)]] = sql"call app_glimpulse_invitation_pkg.n_send_invitation('xyz', 1000, 1, 'me@here.com', NULL, 'I', ${out})".as[(Int)]
val result: Future[Int] = db.run(call)
但这也无济于事，产生编译错误：
[error] /Users/zbeckman/Projects/Glimpulse/Server-2/project/glimpulse-server/app/controllers/GPInviteService/GPInviteService.scala:126: type mismatch;
[error] found : slick.driver.PostgresDriver.api.DBIO[Seq[Int]]
[error] (which expands to) slick.dbio.DBIOAction[Seq[Int],slick.dbio.NoStream,slick.dbio.Effect.All]
[error] required: slick.dbio.DBIOAction[Int,slick.dbio.NoStream,Nothing]
[error] val result: Future[Int] = db.run(call)
[error] ^
我确实在会话中找到了（在浏览 Slick API 时）prepareCall，但是同样......没有关于如何使用这个东西的文档。
我们将不胜感激任何和所有建议。这对我来说已经成为一个巨大的障碍，因为我们确实需要对我们的 Postgres 存储过程进行工作调用。谢谢。
好吧，在对相互矛盾的文档进行大量研究和审查之后，我找到了答案。不幸的是，这不是我要找的那个：
For database functions that return complete tables or stored
procedures please use Plain SQL Queries. Stored procedures that return
multiple result sets are currently not supported.
最重要的是，Slick 不支持开箱即用的存储函数或过程，因此我们必须自己编写。
答案是通过抓取会话对象从 Slick 中退出，然后使用标准 JDBC 来管理过程调用。对于那些熟悉 JDBC 的人来说，这可不是件愉快的事……但是，幸运的是，借助 Scala，我们可以使用模式匹配做一些非常好的技巧，从而使工作变得更容易。
我的第一步是组装一个干净的外部 API。这就是它最终的样子：
val db = Database.forDataSource(DB.getDataSource)
var response: Option[GPInviteResponse] = None
db.withSession {
implicit session => {
val parameters = GPProcedureParameterSet(
GPOut(Types.INTEGER) ::
GPIn(Option(i.token), Types.VARCHAR) ::
GPIn(recipientAccountId, Types.INTEGER) ::
GPIn(Option(contactType), Types.INTEGER) ::
GPIn(contactValue, Types.VARCHAR) ::
GPIn(None, Types.INTEGER) ::
GPIn(Option(requestType), Types.CHAR) ::
GPOut(Types.INTEGER) ::
Nil
)
val result = execute(session.conn, GPProcedure.SendInvitation, parameters)
val rc = result.head.asInstanceOf[Int]
Logger(s"FUNC return code: $rc")
response = rc match {
case 0 => Option(GPInviteResponse(true, None, None))
case _ => Option(GPInviteResponse(false, None, Option(GPError.errorForCode(rc))))
}
}
}
db.close()
这是一个快速演练：我创建了一个简单的容器来模拟存储过程调用。 GPProcedureParameterSet 可以包含 GPIn、GPOut 或 GPInOut 实例的列表。这些中的每一个都将值映射到 JDBC 类型。容器如下所示：
case class GPOut(parameterType: Int) extends GPProcedureParameter
object GPOut
case class GPIn(value: Option[Any], parameterType: Int) extends GPProcedureParameter
object GPIn
case class GPInOut(value: Option[Any], parameterType: Int) extends GPProcedureParameter
object GPInOut
case class GPProcedureParameterSet(parameters: List[GPProcedureParameter])
object GPProcedureParameterSet
object GPProcedure extends Enumeration {
type GPProcedure = Value
val SendInvitation = Value("{?=call app_glimpulse_invitation_pkg.n_send_invitation(?, ?, ?, ?, ?, ?, ?)}")
}
为了完整起见，我包括了 GPProcedure 枚举，以便您可以将它们放在一起。
所有这些都交给了我的 execute() 函数。它又大又脏，闻起来像老式的 JDBC，我相信我会大大改进 Scala。我昨晚凌晨 3 点真的完成了这个……但它确实有效，而且效果非常好。请注意，这个特定的 execute() 函数 returns 包含所有 OUT 参数的 List ......我将不得不编写一个单独的 executeQuery() 函数来处理一个过程 returns一个resultSet。 （虽然区别是微不足道的：您只需编写一个循环来获取 resultSet.next 并将其全部填充到 List 或您想要的任何其他结构中）。
这是讨厌的 Scala<->JDBC 映射 execute() 函数：
def execute(connection: Connection, procedure: GPProcedure, ps: GPProcedureParameterSet) = {
val cs = connection.prepareCall(procedure.toString)
var index = 0
for (parameter <- ps.parameters) {
index = index + 1
parameter match {
// Handle any IN (or INOUT) types: If the optional value is None, set it to NULL, otherwise, map it according to
// the actual object value and type encoding:
case p: GPOut => cs.registerOutParameter(index, p.parameterType)
case GPIn(None, t) => cs.setNull(index, t)
case GPIn(v: Some[_], Types.NUMERIC | Types.DECIMAL) => cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal])
case GPIn(v: Some[_], Types.BIGINT) => cs.setLong(index, v.get.asInstanceOf[Long])
case GPIn(v: Some[_], Types.INTEGER) => cs.setInt(index, v.get.asInstanceOf[Int])
case GPIn(v: Some[_], Types.VARCHAR | Types.LONGVARCHAR) => cs.setString(index, v.get.asInstanceOf[String])
case GPIn(v: Some[_], Types.CHAR) => cs.setString(index, v.get.asInstanceOf[String].head.toString)
case GPInOut(None, t) => cs.setNull(index, t)
// Now handle all of the OUT (or INOUT) parameters, these we just need to set the return value type:
case GPInOut(v: Some[_], Types.NUMERIC) => {
cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal]); cs.registerOutParameter(index, Types.NUMERIC)
}
case GPInOut(v: Some[_], Types.DECIMAL) => {
cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal]); cs.registerOutParameter(index, Types.DECIMAL)
}
case GPInOut(v: Some[_], Types.BIGINT) => {
cs.setLong(index, v.get.asInstanceOf[Long]); cs.registerOutParameter(index, Types.BIGINT)
}
case GPInOut(v: Some[_], Types.INTEGER) => {
cs.setInt(index, v.get.asInstanceOf[Int]); cs.registerOutParameter(index, Types.INTEGER)
}
case GPInOut(v: Some[_], Types.VARCHAR) => {
cs.setString(index, v.get.asInstanceOf[String]); cs.registerOutParameter(index, Types.VARCHAR)
}
case GPInOut(v: Some[_], Types.LONGVARCHAR) => {
cs.setString(index, v.get.asInstanceOf[String]); cs.registerOutParameter(index, Types.LONGVARCHAR)
}
case GPInOut(v: Some[_], Types.CHAR) => {
cs.setString(index, v.get.asInstanceOf[String].head.toString); cs.registerOutParameter(index, Types.CHAR)
}
case _ => { Logger(s"Failed to match GPProcedureParameter in executeFunction (IN): index $index (${parameter.toString})") }
}
}
cs.execute()
// Now, step through each of the parameters, and get the corresponding result from the execute statement. If there is
// no result for the specified column (index), we'll basically end up getting a "nothing" back, which we strip out.
index = 0
val results: List[Any] = for (parameter <- ps.parameters) yield {
index = index + 1
parameter match {
case GPOut(Types.NUMERIC) | GPOut(Types.DECIMAL) => cs.getBigDecimal(index)
case GPOut(Types.BIGINT) => cs.getLong(index)
case GPOut(Types.INTEGER) => cs.getInt(index)
case GPOut(Types.VARCHAR | Types.LONGVARCHAR | Types.CHAR) => cs.getString(index)
case GPInOut(v: Some[_], Types.NUMERIC | Types.DECIMAL) => cs.getInt(index)
case GPInOut(v: Some[_], Types.BIGINT) => cs.getLong(index)
case GPInOut(v: Some[_], Types.INTEGER) => cs.getInt(index)
case GPInOut(v: Some[_], Types.VARCHAR | Types.LONGVARCHAR | Types.CHAR) => cs.getString(index)
case _ => {
Logger(s"Failed to match GPProcedureParameter in executeFunction (OUT): index $index (${parameter.toString})")
}
}
}
cs.close()
// Return the function return parameters (there should always be one, the caller will get a List with as many return
// parameters as we receive):
results.filter(_ != (()))
}
我正在尝试从 Slick 3.0（在 Play Framework 中）调用存储过程。我一遍又一遍地查看文档，但不幸的是 plain SQL docs at Typesafe 从未显示调用存储过程。
看起来很简单的事情导致了一个典型的晦涩难懂的 Scala 错误消息：
val f = Try {
val call: DBIO[Int] = sqlu"?=call app_glimpulse_invitation_pkg.n_send_invitation(${i.token}, ${i.recipientAccountId.getOrElse(None)}, ${i.email}, ${i.phoneNumber}, ${requestType})"
val result: Future[Int] = db.run(call)
val r = Await.result(result, Duration.Inf) // should only return one; use .seq.count(_.id != null)) to validate
val z = result.value.get.get // should return the stored procedure return value...?
}
以上代码导致此编译器错误：
[error] /Users/zbeckman/Projects/Glimpulse/Server-2/project/glimpulse-server/app/controllers/GPInviteService/GPInviteService.scala:120: could not find implicit value for parameter e: slick.jdbc.SetParameter[Product with Serializable]
[error] val call: DBIO[Int] = sqlu"?=call app_glimpulse_invitation_pkg.n_send_invitation(${i.token}, ${i.recipientAccountId.getOrElse(None)}, ${i.email}, ${i.phoneNumber}, ${requestType})"
[error] ^
如果我使用纯硬编码的调用语句（删除所有 ${i.xyz} 引用，我可以编译它...但是，我收到运行时错误报告 Update statements should not return a result set.
这导致我将语句更改为常规 sql 调用：
val call: DBIO[Seq[(Int)]] = sql"call app_glimpulse_invitation_pkg.n_send_invitation('xyz', 1000, 1, 'me@here.com', NULL, 'I', ${out})".as[(Int)]
val result: Future[Int] = db.run(call)
但这也无济于事，产生编译错误：
[error] /Users/zbeckman/Projects/Glimpulse/Server-2/project/glimpulse-server/app/controllers/GPInviteService/GPInviteService.scala:126: type mismatch;
[error] found : slick.driver.PostgresDriver.api.DBIO[Seq[Int]]
[error] (which expands to) slick.dbio.DBIOAction[Seq[Int],slick.dbio.NoStream,slick.dbio.Effect.All]
[error] required: slick.dbio.DBIOAction[Int,slick.dbio.NoStream,Nothing]
[error] val result: Future[Int] = db.run(call)
[error] ^
我确实在会话中找到了（在浏览 Slick API 时）prepareCall，但是同样......没有关于如何使用这个东西的文档。
我们将不胜感激任何和所有建议。这对我来说已经成为一个巨大的障碍，因为我们确实需要对我们的 Postgres 存储过程进行工作调用。谢谢。
好吧，在对相互矛盾的文档进行大量研究和审查之后，我找到了答案。不幸的是，这不是我要找的那个：
For database functions that return complete tables or stored procedures please use Plain SQL Queries. Stored procedures that return multiple result sets are currently not supported.
最重要的是，Slick 不支持开箱即用的存储函数或过程，因此我们必须自己编写。
答案是通过抓取会话对象从 Slick 中退出，然后使用标准 JDBC 来管理过程调用。对于那些熟悉 JDBC 的人来说，这可不是件愉快的事……但是，幸运的是，借助 Scala，我们可以使用模式匹配做一些非常好的技巧，从而使工作变得更容易。
我的第一步是组装一个干净的外部 API。这就是它最终的样子：
val db = Database.forDataSource(DB.getDataSource)
var response: Option[GPInviteResponse] = None
db.withSession {
implicit session => {
val parameters = GPProcedureParameterSet(
GPOut(Types.INTEGER) ::
GPIn(Option(i.token), Types.VARCHAR) ::
GPIn(recipientAccountId, Types.INTEGER) ::
GPIn(Option(contactType), Types.INTEGER) ::
GPIn(contactValue, Types.VARCHAR) ::
GPIn(None, Types.INTEGER) ::
GPIn(Option(requestType), Types.CHAR) ::
GPOut(Types.INTEGER) ::
Nil
)
val result = execute(session.conn, GPProcedure.SendInvitation, parameters)
val rc = result.head.asInstanceOf[Int]
Logger(s"FUNC return code: $rc")
response = rc match {
case 0 => Option(GPInviteResponse(true, None, None))
case _ => Option(GPInviteResponse(false, None, Option(GPError.errorForCode(rc))))
}
}
}
db.close()
这是一个快速演练：我创建了一个简单的容器来模拟存储过程调用。 GPProcedureParameterSet 可以包含 GPIn、GPOut 或 GPInOut 实例的列表。这些中的每一个都将值映射到 JDBC 类型。容器如下所示：
case class GPOut(parameterType: Int) extends GPProcedureParameter
object GPOut
case class GPIn(value: Option[Any], parameterType: Int) extends GPProcedureParameter
object GPIn
case class GPInOut(value: Option[Any], parameterType: Int) extends GPProcedureParameter
object GPInOut
case class GPProcedureParameterSet(parameters: List[GPProcedureParameter])
object GPProcedureParameterSet
object GPProcedure extends Enumeration {
type GPProcedure = Value
val SendInvitation = Value("{?=call app_glimpulse_invitation_pkg.n_send_invitation(?, ?, ?, ?, ?, ?, ?)}")
}
为了完整起见，我包括了 GPProcedure 枚举，以便您可以将它们放在一起。
所有这些都交给了我的 execute() 函数。它又大又脏，闻起来像老式的 JDBC，我相信我会大大改进 Scala。我昨晚凌晨 3 点真的完成了这个……但它确实有效，而且效果非常好。请注意，这个特定的 execute() 函数 returns 包含所有 OUT 参数的 List ......我将不得不编写一个单独的 executeQuery() 函数来处理一个过程 returns一个resultSet。 （虽然区别是微不足道的：您只需编写一个循环来获取 resultSet.next 并将其全部填充到 List 或您想要的任何其他结构中）。
这是讨厌的 Scala<->JDBC 映射 execute() 函数：
def execute(connection: Connection, procedure: GPProcedure, ps: GPProcedureParameterSet) = {
val cs = connection.prepareCall(procedure.toString)
var index = 0
for (parameter <- ps.parameters) {
index = index + 1
parameter match {
// Handle any IN (or INOUT) types: If the optional value is None, set it to NULL, otherwise, map it according to
// the actual object value and type encoding:
case p: GPOut => cs.registerOutParameter(index, p.parameterType)
case GPIn(None, t) => cs.setNull(index, t)
case GPIn(v: Some[_], Types.NUMERIC | Types.DECIMAL) => cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal])
case GPIn(v: Some[_], Types.BIGINT) => cs.setLong(index, v.get.asInstanceOf[Long])
case GPIn(v: Some[_], Types.INTEGER) => cs.setInt(index, v.get.asInstanceOf[Int])
case GPIn(v: Some[_], Types.VARCHAR | Types.LONGVARCHAR) => cs.setString(index, v.get.asInstanceOf[String])
case GPIn(v: Some[_], Types.CHAR) => cs.setString(index, v.get.asInstanceOf[String].head.toString)
case GPInOut(None, t) => cs.setNull(index, t)
// Now handle all of the OUT (or INOUT) parameters, these we just need to set the return value type:
case GPInOut(v: Some[_], Types.NUMERIC) => {
cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal]); cs.registerOutParameter(index, Types.NUMERIC)
}
case GPInOut(v: Some[_], Types.DECIMAL) => {
cs.setBigDecimal(index, v.get.asInstanceOf[java.math.BigDecimal]); cs.registerOutParameter(index, Types.DECIMAL)
}
case GPInOut(v: Some[_], Types.BIGINT) => {
cs.setLong(index, v.get.asInstanceOf[Long]); cs.registerOutParameter(index, Types.BIGINT)
}
case GPInOut(v: Some[_], Types.INTEGER) => {
cs.setInt(index, v.get.asInstanceOf[Int]); cs.registerOutParameter(index, Types.INTEGER)
}
case GPInOut(v: Some[_], Types.VARCHAR) => {
cs.setString(index, v.get.asInstanceOf[String]); cs.registerOutParameter(index, Types.VARCHAR)
}
case GPInOut(v: Some[_], Types.LONGVARCHAR) => {
cs.setString(index, v.get.asInstanceOf[String]); cs.registerOutParameter(index, Types.LONGVARCHAR)
}
case GPInOut(v: Some[_], Types.CHAR) => {
cs.setString(index, v.get.asInstanceOf[String].head.toString); cs.registerOutParameter(index, Types.CHAR)
}
case _ => { Logger(s"Failed to match GPProcedureParameter in executeFunction (IN): index $index (${parameter.toString})") }
}
}
cs.execute()
// Now, step through each of the parameters, and get the corresponding result from the execute statement. If there is
// no result for the specified column (index), we'll basically end up getting a "nothing" back, which we strip out.
index = 0
val results: List[Any] = for (parameter <- ps.parameters) yield {
index = index + 1
parameter match {
case GPOut(Types.NUMERIC) | GPOut(Types.DECIMAL) => cs.getBigDecimal(index)
case GPOut(Types.BIGINT) => cs.getLong(index)
case GPOut(Types.INTEGER) => cs.getInt(index)
case GPOut(Types.VARCHAR | Types.LONGVARCHAR | Types.CHAR) => cs.getString(index)
case GPInOut(v: Some[_], Types.NUMERIC | Types.DECIMAL) => cs.getInt(index)
case GPInOut(v: Some[_], Types.BIGINT) => cs.getLong(index)
case GPInOut(v: Some[_], Types.INTEGER) => cs.getInt(index)
case GPInOut(v: Some[_], Types.VARCHAR | Types.LONGVARCHAR | Types.CHAR) => cs.getString(index)
case _ => {
Logger(s"Failed to match GPProcedureParameter in executeFunction (OUT): index $index (${parameter.toString})")
}
}
}
cs.close()
// Return the function return parameters (there should always be one, the caller will get a List with as many return
// parameters as we receive):
results.filter(_ != (()))
}