Question

当我尝试运行Play应用程序（Play 2.5.4）时，出现以下错误：

ProvisionException: Unable to provision, see the following errors:

1) No implementation for play.api.db.Database was bound.
  while locating play.api.db.Database
    for parameter 0 at ds.qb.manage.ManageQueryBuilder.<init>(ManageQueryBuilder.scala:30)
  while locating ds.qb.manage.ManageQueryBuilder
    for parameter 16 at router.Routes.<init>(Routes.scala:107)
  while locating router.Routes
  while locating play.api.inject.RoutesProvider
  while locating play.api.routing.Router
    for parameter 0 at play.api.http.JavaCompatibleHttpRequestHandler.<init>(HttpRequestHandler.scala:200)
  while locating play.api.http.JavaCompatibleHttpRequestHandler
  while locating play.api.http.HttpRequestHandler
    for parameter 4 at play.api.DefaultApplication.<init>(Application.scala:221)
  at play.api.DefaultApplication.class(Application.scala:221)
  while locating play.api.DefaultApplication
  while locating play.api.Application

这是我的数据库设置，有什么想法吗？我有两次定义，因为我通过Slick和JDBC访问数据库。

play.db {
  # The combination of these two settings results in "db.default" as the
  # default JDBC pool:
  config = "db"
  default = "default"

  # Play uses HikariCP as the default connection pool.  You can override
  # settings by changing the prototype:
  #prototype {
    # Sets a fixed JDBC connection pool size of 50
    #hikaricp.minimumIdle = 50
    #hikaricp.maximumPoolSize = 50
  #}
}

  db.default.driver=com.mysql.jdbc.Driver
  db.default.url="jdbc:mysql://localhost:3306/db2"
  db.default.username=root
  db.default.password=xxxxx


db2 = {
  url = "jdbc:mysql://localhost:3306/db2"
  driver = com.mysql.jdbc.Driver
  connectionPool = disabled
  keepAliveConnection = true
  user=root
  password=xxxxxx
}

更新

build.sbt文件：

name := """myapp"""

version := "1.0-SNAPSHOT"

lazy val root = (project in file(".")).enablePlugins(PlayScala)

scalaVersion := "2.11.7"

libraryDependencies ++= Seq(
  jdbc,
  cache,
  ws,
  "org.scalatestplus.play" %% "scalatestplus-play" % "1.5.1" % Test
)

libraryDependencies += "com.typesafe.slick" %% "slick" % "3.1.1"
libraryDependencies += "com.typesafe.play" %% "play-slick" % "2.0.0"
libraryDependencies += "mysql" % "mysql-connector-java" % "5.1.18"
libraryDependencies += "org.pivot4j" % "pivot4j-core" % "0.9" 
libraryDependencies += "org.scalaz" %% "scalaz-core" % "7.1.0" 

// properties file
libraryDependencies += "com.typesafe" % "config" % "1.3.0" 

libraryDependencies += "org.slf4j" % "slf4j-nop" % "1.6.4"
libraryDependencies += "log4j" % "log4j" % "1.2.14"

resolvers += "scalaz-bintray" at "http://dl.bintray.com/scalaz/releases"

// mondrian
resolvers += "Pentaho Releases" at "http://repository.pentaho.org/artifactory/repo/"

Answer 1

在我的情况下，application.conf没有适当的数据库参数

示例

  db.default.driver = org.h2.Driver
  db.default.url = "jdbc:h2:mem:play"
  db.default.username = sa
  db.default.password = ""

Answer 2

您的application.conf应该如下所示：

db.dev_mysql {
  driver = "org.mariadb.jdbc.Driver" 
  # JDBC connection string. "useAffectedRows" must be set to true.
  url = "jdbc:mysql://dev01:3306/dev_db?autoReconnect=true&characterEncoding=utf-8&connectionCollation=utf8_unicode_ci&useSSL=false&useAffectedRows=true"

  url = ${?DATABASE_URL}
  hikaricp {
    # Whether autocommit should be used
    autoCommit = true
    # The connection timeout
    connectionTimeout = 10 seconds
    # The idle timeout
    idleTimeout = 5 minutes
    # The max lifetime of a connection
    maxLifetime = 10 minutes
    # If non null, the query that should be used to test connections
    connectionTestQuery = "SELECT 1"
    # Minimum number of idle connections maintained in the pool.
    minimumIdle = 10
    # The maximum number of connections to make.
    maximumPoolSize = 20
    # If non null, sets the name of the connection pool. Primarily used for stats reporting.
    poolName = "mysql"
    # A SQL statement that will be executed after every new connection creation before adding it to the pool
    connectionInitSql = "SELECT 1"
    # If non null, sets the transaction isolation level
    transactionIsolation = TRANSACTION_READ_COMMITTED
    # The validation timeout to use
    validationTimeout = 5 seconds
  }
}

开始播放Play时，它通过从application.conf中的db。dev_mysql json加载参数来创建名为dev_mysql的数据库连接池。

如何执行查询：

我们可以使用NamedDatabase注释。

class CustomController @Inject() (
                                             val config: Configuration,
                                             @play.db.NamedDatabase("dev_mysql") db : Database,
                                             controllerComponents: ControllerComponents,
                                           ) extends ApiController(controllerComponents)  {
    def createReportDefinition = Action { implicit ctx ⇒

      val conn = db.getConnection(false)
      val sqlQuery = "select 1"
      val prepStmt: PreparedStatement = conn.prepareStatement(sqlQuery)
      prepStmt.execute()
      conn.commit()
      conn.close()
      Ok
      }

启动时播放错误：没有绑定play.api.db.Database的实现

2 个答案: