SDP(4):ScalikeJDBC- JDBC-Engine:Updating详解编程语言

    在上一篇博文里我们把JDBC-Engine的读取操作部分分离出来进行了讨论,在这篇准备把更新Update部分功能介绍一下。当然,JDBC-Engine的功能是基于ScalikeJDBC的,所有的操作和属性都包嵌在SQL这个类型中:

/** 
 * SQL abstraction. 
 * 
 * @param statement SQL template 
 * @param rawParameters parameters 
 * @param f  extractor function 
 * @tparam A return type 
 */ 
abstract class SQL[A, E <: WithExtractor]( 
  val statement: String, 
  private[scalikejdbc] val rawParameters: Seq[Any] 
)(f: WrappedResultSet => A) 
{...}

Update功能置于下面这几个子类中:

/** 
 * SQL which execute java.sql.Statement#executeUpdate(). 
 * 
 * @param statement SQL template 
 * @param parameters parameters 
 * @param before before filter 
 * @param after after filter 
 */ 
class SQLUpdate(val statement: String, val parameters: Seq[Any], val tags: Seq[String] = Nil)( 
    val before: (PreparedStatement) => Unit 
)( 
    val after: (PreparedStatement) => Unit 
) { 
 
  def apply()(implicit session: DBSession): Int = { 
    val attributesSwitcher = new DBSessionAttributesSwitcher(SQL("").tags(tags: _*)) 
    session match { 
      case AutoSession => 
        DB.autoCommit(DBSessionWrapper(_, attributesSwitcher).updateWithFilters(before, after, statement, parameters: _*)) 
      case NamedAutoSession(name, _) => 
        NamedDB(name, session.settings).autoCommit(DBSessionWrapper(_, attributesSwitcher).updateWithFilters(before, after, statement, parameters: _*)) 
      case ReadOnlyAutoSession => 
        DB.readOnly(DBSessionWrapper(_, attributesSwitcher).updateWithFilters(before, after, statement, parameters: _*)) 
      case ReadOnlyNamedAutoSession(name, _) => 
        NamedDB(name, session.settings).readOnly(DBSessionWrapper(_, attributesSwitcher).updateWithFilters(before, after, statement, parameters: _*)) 
      case _ => 
        DBSessionWrapper(session, attributesSwitcher).updateWithFilters(before, after, statement, parameters: _*) 
    } 
  } 
 
} 
 
/** 
 * SQL which execute java.sql.Statement#execute(). 
 * 
 * @param statement SQL template 
 * @param parameters parameters 
 * @param before before filter 
 * @param after after filter 
 */ 
class SQLExecution(val statement: String, val parameters: Seq[Any], val tags: Seq[String] = Nil)( 
    val before: (PreparedStatement) => Unit 
)( 
    val after: (PreparedStatement) => Unit 
) { 
 
  def apply()(implicit session: DBSession): Boolean = { 
    val attributesSwitcher = new DBSessionAttributesSwitcher(SQL("").tags(tags: _*)) 
    val f: DBSession => Boolean = DBSessionWrapper(_, attributesSwitcher).executeWithFilters(before, after, statement, parameters: _*) 
    // format: OFF 
    session match { 
      case AutoSession                       => DB.autoCommit(f) 
      case NamedAutoSession(name, _)         => NamedDB(name, session.settings).autoCommit(f) 
      case ReadOnlyAutoSession               => DB.readOnly(f) 
      case ReadOnlyNamedAutoSession(name, _) => NamedDB(name, session.settings).readOnly(f) 
      case _                                 => f(session) 
    } 
    // format: ON 
  } 
 
} 
/** 
 * SQL which execute java.sql.Statement#executeBatch(). 
 * 
 * @param statement SQL template 
 * @param parameters parameters 
 */ 
class SQLBatch(val statement: String, val parameters: Seq[Seq[Any]], val tags: Seq[String] = Nil) { 
 
  def apply[C[_]]()(implicit session: DBSession, cbf: CanBuildFrom[Nothing, Int, C[Int]]): C[Int] = { 
    val attributesSwitcher = new DBSessionAttributesSwitcher(SQL("").tags(tags: _*)) 
    val f: DBSession => C[Int] = DBSessionWrapper(_, attributesSwitcher).batch(statement, parameters: _*) 
    // format: OFF 
    session match { 
      case AutoSession                       => DB.autoCommit(f) 
      case NamedAutoSession(name, _)         => NamedDB(name, session.settings).autoCommit(f) 
      case ReadOnlyAutoSession               => DB.readOnly(f) 
      case ReadOnlyNamedAutoSession(name, _) => NamedDB(name, session.settings).readOnly(f) 
      case _                                 => f(session) 
    } 
    // format: ON 
  } 
 
}

按照JDBC-Engine的功能设计要求,我们大约把Update功能分成数据表构建操作DDL、批次运算Batch、和普通Update几种类型。我们是通过JDBCContext来定义具体的Update功能类型:

object JDBCContext { 
type SQLTYPE = Int 
val SQL_SELECT: Int = 0 
val SQL_EXEDDL= 1 
val SQL_UPDATE = 2 
val RETURN_GENERATED_KEYVALUE = true 
val RETURN_UPDATED_COUNT = false 
} 
case class JDBCContext( 
dbName: Symbol, 
statements: Seq[String] = Nil, 
parameters: Seq[Seq[Any]] = Nil, 
fetchSize: Int = 100, 
queryTimeout: Option[Int] = None, 
queryTags: Seq[String] = Nil, 
sqlType: JDBCContext.SQLTYPE = JDBCContext.SQL_SELECT, 
batch: Boolean = false, 
returnGeneratedKey: Seq[Option[Any]] = Nil, 
// no return: None, return by index: Some(1), by name: Some("id") 
preAction: Option[PreparedStatement => Unit] = None, 
postAction: Option[PreparedStatement => Unit] = None) { 
ctx => 
//helper functions 
 
def appendTag(tag: String): JDBCContext = ctx.copy(queryTags = ctx.queryTags :+ tag) 
def appendTags(tags: Seq[String]): JDBCContext = ctx.copy(queryTags = ctx.queryTags ++ tags) 
def setFetchSize(size: Int): JDBCContext = ctx.copy(fetchSize = size) 
def setQueryTimeout(time: Option[Int]): JDBCContext = ctx.copy(queryTimeout = time) 
def setPreAction(action: Option[PreparedStatement => Unit]): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && 
!ctx.batch && ctx.statements.size == 1) 
ctx.copy(preAction = action) 
else 
throw new IllegalStateException("JDBCContex setting error: preAction not supported!") 
} 
def setPostAction(action: Option[PreparedStatement => Unit]): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && 
!ctx.batch && ctx.statements.size == 1) 
ctx.copy(postAction = action) 
else 
throw new IllegalStateException("JDBCContex setting error: preAction not supported!") 
} 
def appendDDLCommand(_statement: String, _parameters: Any*): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_EXEDDL) { 
ctx.copy( 
statements = ctx.statements ++ Seq(_statement), 
parameters = ctx.parameters ++ Seq(Seq(_parameters)) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: option not supported!") 
} 
def appendUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && !ctx.batch) { 
ctx.copy( 
statements = ctx.statements ++ Seq(_statement), 
parameters = ctx.parameters ++ Seq(_parameters), 
returnGeneratedKey = ctx.returnGeneratedKey ++ (if (_returnGeneratedKey) Seq(Some(1)) else Seq(None)) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: option not supported!") 
} 
def appendBatchParameters(_parameters: Any*): JDBCContext = { 
if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch) 
throw new IllegalStateException("JDBCContex setting error: batch parameters only supported for SQL_UPDATE and batch = true!") 
var matchParams = true 
if (ctx.parameters != Nil) 
if (ctx.parameters.head.size != _parameters.size) 
matchParams = false 
if (matchParams) { 
ctx.copy( 
parameters = ctx.parameters ++ Seq(_parameters) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: batch command parameters not match!") 
} 
def setBatchReturnGeneratedKeyOption(returnKey: Boolean): JDBCContext = { 
if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch) 
throw new IllegalStateException("JDBCContex setting error: only supported in batch update commands!") 
ctx.copy( 
returnGeneratedKey = if (returnKey) Seq(Some(1)) else Nil 
) 
} 
def setQueryCommand(_statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
sqlType = JDBCContext.SQL_SELECT, 
batch = false 
) 
} 
def setDDLCommand(_statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
sqlType = JDBCContext.SQL_EXEDDL, 
batch = false 
) 
} 
def setUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
returnGeneratedKey = if (_returnGeneratedKey) Seq(Some(1)) else Seq(None), 
sqlType = JDBCContext.SQL_UPDATE, 
batch = false 
) 
} 
def setBatchCommand(_statement: String): JDBCContext = { 
ctx.copy ( 
statements = Seq(_statement), 
sqlType = JDBCContext.SQL_UPDATE, 
batch = true 
) 
} 
}

JDBCContext还提供了不少的Helper函数来协助构建特别功能的JDBCContext对象,如:setQueryCommand, setDDLCommand, setUpdateCommand, setBatchCommand。这些Helper函数提供Update功能定义的几个主要元素包括:SQL语句主体包括参数占位的statement、输入参数parameter、是否需要返回系统自动产生的主键returnGeneratedKey。在ScalikeJDBC中所有类型的Update功能可以用下面几类内部函数实现,包括:

  private[this] def batchInternal[C[_], A]( 
template: String, 
paramsList: Seq[Seq[Any]], 
execute: StatementExecutor => scala.Array[A] 
)(implicit cbf: CanBuildFrom[Nothing, A, C[A]]): C[A] = { 
ensureNotReadOnlySession(template) 
paramsList match { 
case Nil => Seq.empty[A].to[C] 
case _ => 
using(createBatchStatementExecutor( 
conn = conn, 
template = template, 
returnGeneratedKeys = false, 
generatedKeyName = None 
)) { executor => 
paramsList.foreach { 
params => 
executor.bindParams(params) 
executor.addBatch() 
} 
execute(executor).to[C] 
} 
} 
} 
private[this] def updateWithFiltersInternal[A]( 
returnGeneratedKeys: Boolean, 
before: (PreparedStatement) => Unit, 
after: (PreparedStatement) => Unit, 
template: String, 
execute: StatementExecutor => A, 
params: Seq[Any] 
): A = { 
ensureNotReadOnlySession(template) 
using(createStatementExecutor( 
conn = conn, 
template = template, 
params = params, 
returnGeneratedKeys = returnGeneratedKeys 
)) { 
executor => 
before(executor.underlying) 
val count = execute(executor) 
after(executor.underlying) 
count 
} 
} 
private[this] def updateWithAutoGeneratedKeyNameAndFiltersInternal[A]( 
returnGeneratedKeys: Boolean, 
generatedKeyName: String, 
before: (PreparedStatement) => Unit, 
after: (PreparedStatement) => Unit, 
template: String, 
execute: StatementExecutor => A, 
params: Seq[Any] 
): A = { 
ensureNotReadOnlySession(template) 
using(createStatementExecutor( 
conn = conn, 
template = template, 
params = params, 
returnGeneratedKeys = returnGeneratedKeys, 
generatedKeyName = Option(generatedKeyName) 
)) { 
executor => 
before(executor.underlying) 
val count = execute(executor) 
after(executor.underlying) 
count 
} 
}

我们可以看到所有类型的Update都是通过构建StatementExecutor并按其属性进行运算来实现的:

/** 
* java.sql.Statement Executor. 
* 
* @param underlying preparedStatement 
* @param template SQL template 
* @param singleParams parameters for single execution (= not batch execution) 
* @param isBatch is batch flag 
*/ 
case class StatementExecutor( 
underlying: PreparedStatement, 
template: String, 
connectionAttributes: DBConnectionAttributes, 
singleParams: Seq[Any] = Nil, 
tags: Seq[String] = Nil, 
isBatch: Boolean = false, 
settingsProvider: SettingsProvider = SettingsProvider.default 
) extends LogSupport with UnixTimeInMillisConverterImplicits with AutoCloseable {...}

这个StatementExcutor类的属性和我们的JDBCContext属性很接近。好了,回到JDBC-Engine Update功能定义。首先是DDL功能:

 def jdbcExcuteDDL(ctx: JDBCContext): Try[String] = { 
if (ctx.sqlType != SQL_EXEDDL) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_EXEDDL'!")) 
} 
else { 
NamedDB(ctx.dbName) localTx { implicit session => 
Try { 
ctx.statements.foreach { stm => 
val ddl = new SQLExecution(statement = stm, parameters = Nil)( 
before = WrappedResultSet => {})( 
after = WrappedResultSet => {}) 
ddl.apply() 
} 
"SQL_EXEDDL executed succesfully." 
} 
} 
} 
}

 所有JDBC-Engine的Update功能都是一个事务处理Transaction中的多条更新语句。DDL语句不需要参数所以只需要提供statement就足够了。下面是这个函数的使用示范:

 ConfigDBsWithEnv("dev").setup('h2) 
ConfigDBsWithEnv("dev").loadGlobalSettings() 
val dropSQL: String =""" 
      drop table members 
""" 
 
val createSQL: String =""" 
    create table members ( 
id serial not null primary key, 
name varchar(30) not null, 
description varchar(1000), 
birthday date, 
created_at timestamp not null, 
picture blob 
)""" 
 
var ctx = JDBCContext('h2) 
try { 
ctx = ctx.setDDLCommand(dropSQL) 
.appendDDLCommand(createSQL) 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
val resultCreateTable = jdbcExcuteDDL(ctx) 
resultCreateTable match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
}

在这里我们修改了上次使用的members表,增加了一个blob类的picture列。这个示范在一个完整的Transaction里包括了两条DDL语句。

批次更新batch-update是指多条输入参数在一条统一的statement上施用:

  def jdbcBatchUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (ctx.statements == Nil) 
throw new IllegalStateException("JDBCContex setting error: statements empty!") 
if (ctx.sqlType != SQL_UPDATE) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!")) 
} 
else { 
if (ctx.batch) { 
if (noReturnKey(ctx)) { 
val usql = SQL(ctx.statements.head) 
.tags(ctx.queryTags: _*) 
.batch(ctx.parameters: _*) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
usql.apply[Seq]() 
Seq.empty[Long].to[C] 
} 
} 
} else { 
val usql = new SQLBatchWithGeneratedKey(ctx.statements.head, ctx.parameters, ctx.queryTags)(None) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
usql.apply[C]() 
} 
} 
} 
} else { 
Failure(new IllegalStateException("JDBCContex setting error: must set batch = true !")) 
} 
} 
}

如果batch-update是某种Insert操作的话我们可以通过cox.batch注明返回由JDBC系统自动产生的唯一键。这些主键一般在构建表时注明,包括:serial, auto_increment等。如果不返回主键则返回update语句的更新状态如更新数据条数等。在上面这个函数里SQLBatchWithGeneratedKey.apply()返回insert数据主键,所以statement必须是INSERT语句。SQLBatch.apply()则用来运算update语句并返回更新数据的条数。下面是jdbcBatchUpdate函数的使用示范:

 val insertSQL = "insert into members(name,birthday,description,created_at,picture) values (?, ?, ?, ?, ?)" 
val dateCreated = DateTime.now 
import java.io.FileInputStream 
val picfile = new File("/users/tiger/Nobody.png") 
val fis = new FileInputStream(picfile) 
ctx = JDBCContext('h2) 
try { 
ctx = ctx.setBatchCommand(insertSQL).appendBatchParameters( 
"John",new LocalDate("2008-03-01"),"youngest user",dateCreated,None).appendBatchParameters( 
"peter", None, "no birth date", dateCreated, fis) 
.appendBatchParameters( 
"susan", None, "no birth date", dateCreated, None) 
.setBatchReturnGeneratedKeyOption(JDBCContext.RETURN_GENERATED_KEYVALUE) 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
var resultInserts = jdbcBatchUpdate(ctx) 
resultInserts match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
}

上面这个例子里一个transaction批次包含了三条Insert语句,其中一条涉及存入picture字段:我们只需要把图像文件InputStream作为普通参数传人即可。我们也可以把任何类型的非batch-update语句捆绑在统一的transaction里运算,而且可以指定每条update返回类型:自动产生的主键或者更新数据条数:

def jdbcTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (ctx.statements == Nil) 
throw new IllegalStateException("JDBCContex setting error: statements empty!") 
if (ctx.sqlType != SQL_UPDATE) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!")) 
} 
else { 
if (!ctx.batch) { 
if (ctx.statements.size == 1) 
singleTxUpdate(ctx) 
else 
multiTxUpdates(ctx) 
} else 
Failure(new IllegalStateException("JDBCContex setting error: must set batch = false !")) 
} 
}

这个update函数又被细分为单条语句singleTxUpdate和多条语句multiTxUpdates。无论单条或多条update函数又被分为返回主键或更新状态类型的函数:

 

 private def singleTxUpdateWithReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
val Some(key) :: xs = ctx.returnGeneratedKey 
val params: Seq[Any] = ctx.parameters match { 
case Nil => Nil 
case p@_ => p.head 
} 
val usql = new SQLUpdateWithGeneratedKey(ctx.statements.head, params, ctx.queryTags)(key) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val result = usql.apply() 
Seq(result).to[C] 
} 
} 
} 
private def singleTxUpdateNoReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
val params: Seq[Any] = ctx.parameters match { 
case Nil => Nil 
case p@_ => p.head 
} 
val before = ctx.preAction match { 
case None => pstm: PreparedStatement => {} 
case Some(f) => f 
} 
val after = ctx.postAction match { 
case None => pstm: PreparedStatement => {} 
case Some(f) => f 
} 
val usql = new SQLUpdate(ctx.statements.head,params,ctx.queryTags)(before)(after) 
Try { 
NamedDB(ctx.dbName) localTx {implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val result = usql.apply() 
Seq(result.toLong).to[C] 
} 
} 
} 
private def singleTxUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (noReturnKey(ctx)) 
singleTxUpdateNoReturnKey(ctx) 
else 
singleTxUpdateWithReturnKey(ctx) 
} 
private def noReturnKey(ctx: JDBCContext): Boolean = { 
if (ctx.returnGeneratedKey != Nil) { 
val k :: xs = ctx.returnGeneratedKey 
k match { 
case None => true 
case Some(k) => false 
} 
} else true 
} 
def noActon: PreparedStatement=>Unit = pstm => {} 
def multiTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val keys: Seq[Option[Any]] = ctx.returnGeneratedKey match { 
case Nil => Seq.fill(ctx.statements.size)(None) 
case k@_ => k 
} 
val sqlcmd = ctx.statements zip ctx.parameters zip keys 
val results = sqlcmd.map { case ((stm, param), key) => 
key match { 
case None => 
new SQLUpdate(stm, param, Nil)(noActon)(noActon).apply().toLong 
case Some(k) => 
new SQLUpdateWithGeneratedKey(stm, param, Nil)(k).apply().toLong 
} 
} 
results.to[C] 
} 
} 
}

下面是这个函数的使用示范: 

 val updateSQL = "update members set description = ? where id < ?" 
ctx = JDBCContext('h2) 
try { 
ctx = ctx.setUpdateCommand(JDBCContext.RETURN_GENERATED_KEYVALUE,insertSQL, 
"max", None, "no birth date", dateCreated, None) 
.appendUpdateCommand(JDBCContext.RETURN_UPDATED_COUNT, updateSQL, "id++", 10) 
.appendUpdateCommand(JDBCContext.RETURN_UPDATED_COUNT,"delete members where id = 1") 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
var resultUpdates = jdbcTxUpdates[Vector](ctx) 
resultUpdates match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
}

在这个例子里我们把insert,update和delete混在了一个transaction里。最后,我们再把试验数据,包括blob字段读出来:

  //data model 
case class Member( 
id: Long, 
name: String, 
description: Option[String] = None, 
birthday: Option[LocalDate] = None, 
createdAt: DateTime, 
picture: InputStream) 
//data row converter 
val toMember = (rs: WrappedResultSet) => Member( 
id = rs.long("id"), 
name = rs.string("name"), 
description = rs.stringOpt("description"), 
birthday = rs.jodaLocalDateOpt("birthday"), 
createdAt = rs.jodaDateTime("created_at"), 
picture = rs.binaryStream("picture") 
) 
ctx = JDBCContext('h2) 
ctx = ctx.setQueryCommand("select * from members").setQueryTimeout(Some(1000)) 
val vecMember: Vector[Member] = jdbcQueryResult[Vector,Member](ctx,toMember) 
val buffer = new Array[Byte](1024) 
vecMember.foreach {row => 
println(s"id: ${row.id} name: ${row.name}") 
println(s"name: ${row.name}") 
if (row.picture == null) 
println("picture empty") 
else { 
val fname = s"/users/tiger/pic${row.id}.png" 
val file = new File(fname) 
val output = new FileOutputStream(file) 
println(s"saving picture to $fname") 
row.picture.available() 
while (row.picture.read(buffer) > 0) { 
output.write(buffer) 
} 
output.close() 
} 
}

下面是本次讨论的示范源代码:

build.sbt

name := "learn-scalikeJDBC" 
version := "0.1" 
scalaVersion := "2.12.4" 
// Scala 2.10, 2.11, 2.12 
libraryDependencies ++= Seq( 
"org.scalikejdbc" %% "scalikejdbc"       % "3.1.0", 
"org.scalikejdbc" %% "scalikejdbc-test"   % "3.1.0"   % "test", 
"org.scalikejdbc" %% "scalikejdbc-config"  % "3.1.0", 
"com.h2database"  %  "h2"                % "1.4.196", 
"mysql" % "mysql-connector-java" % "6.0.6", 
"org.postgresql" % "postgresql" % "42.2.0", 
"commons-dbcp" % "commons-dbcp" % "1.4", 
"org.apache.tomcat" % "tomcat-jdbc" % "9.0.2", 
"com.zaxxer" % "HikariCP" % "2.7.4", 
"com.jolbox" % "bonecp" % "0.8.0.RELEASE", 
"com.typesafe.slick" %% "slick" % "3.2.1", 
"ch.qos.logback"  %  "logback-classic"   % "1.2.3" 
)

resources/application.conf

 

# JDBC settings 
test { 
db { 
h2 { 
driver = "org.h2.Driver" 
url = "jdbc:h2:tcp://localhost/~/slickdemo" 
user = "" 
password = "" 
poolInitialSize = 5 
poolMaxSize = 7 
poolConnectionTimeoutMillis = 1000 
poolValidationQuery = "select 1 as one" 
poolFactoryName = "commons-dbcp2" 
} 
} 
db.mysql.driver = "com.mysql.cj.jdbc.Driver" 
db.mysql.url = "jdbc:mysql://localhost:3306/testdb" 
db.mysql.user = "root" 
db.mysql.password = "123" 
db.mysql.poolInitialSize = 5 
db.mysql.poolMaxSize = 7 
db.mysql.poolConnectionTimeoutMillis = 1000 
db.mysql.poolValidationQuery = "select 1 as one" 
db.mysql.poolFactoryName = "bonecp" 
# scallikejdbc Global settings 
scalikejdbc.global.loggingSQLAndTime.enabled = true 
scalikejdbc.global.loggingSQLAndTime.logLevel = info 
scalikejdbc.global.loggingSQLAndTime.warningEnabled = true 
scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000 
scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn 
scalikejdbc.global.loggingSQLAndTime.singleLineMode = false 
scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false 
scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10 
} 
dev { 
db { 
h2 { 
driver = "org.h2.Driver" 
url = "jdbc:h2:tcp://localhost/~/slickdemo" 
user = "" 
password = "" 
poolFactoryName = "hikaricp" 
numThreads = 10 
maxConnections = 12 
minConnections = 4 
keepAliveConnection = true 
} 
mysql { 
driver = "com.mysql.cj.jdbc.Driver" 
url = "jdbc:mysql://localhost:3306/testdb" 
user = "root" 
password = "123" 
poolInitialSize = 5 
poolMaxSize = 7 
poolConnectionTimeoutMillis = 1000 
poolValidationQuery = "select 1 as one" 
poolFactoryName = "bonecp" 
} 
postgres { 
driver = "org.postgresql.Driver" 
url = "jdbc:postgresql://localhost:5432/testdb" 
user = "root" 
password = "123" 
poolFactoryName = "hikaricp" 
numThreads = 10 
maxConnections = 12 
minConnections = 4 
keepAliveConnection = true 
} 
} 
# scallikejdbc Global settings 
scalikejdbc.global.loggingSQLAndTime.enabled = true 
scalikejdbc.global.loggingSQLAndTime.logLevel = info 
scalikejdbc.global.loggingSQLAndTime.warningEnabled = true 
scalikejdbc.global.loggingSQLAndTime.warningThresholdMillis = 1000 
scalikejdbc.global.loggingSQLAndTime.warningLogLevel = warn 
scalikejdbc.global.loggingSQLAndTime.singleLineMode = false 
scalikejdbc.global.loggingSQLAndTime.printUnprocessedStackTrace = false 
scalikejdbc.global.loggingSQLAndTime.stackTraceDepth = 10 
}

JDBCEngine.scala

package jdbccontext 
import java.sql.PreparedStatement 
import scala.collection.generic.CanBuildFrom 
import scalikejdbc._ 
import scala.util._ 
import scalikejdbc.TxBoundary.Try._ 
object JDBCContext { 
type SQLTYPE = Int 
val SQL_SELECT: Int = 0 
val SQL_EXEDDL= 1 
val SQL_UPDATE = 2 
val RETURN_GENERATED_KEYVALUE = true 
val RETURN_UPDATED_COUNT = false 
} 
case class JDBCContext( 
dbName: Symbol, 
statements: Seq[String] = Nil, 
parameters: Seq[Seq[Any]] = Nil, 
fetchSize: Int = 100, 
queryTimeout: Option[Int] = None, 
queryTags: Seq[String] = Nil, 
sqlType: JDBCContext.SQLTYPE = JDBCContext.SQL_SELECT, 
batch: Boolean = false, 
returnGeneratedKey: Seq[Option[Any]] = Nil, 
// no return: None, return by index: Some(1), by name: Some("id") 
preAction: Option[PreparedStatement => Unit] = None, 
postAction: Option[PreparedStatement => Unit] = None) { 
ctx => 
//helper functions 
 
def appendTag(tag: String): JDBCContext = ctx.copy(queryTags = ctx.queryTags :+ tag) 
def appendTags(tags: Seq[String]): JDBCContext = ctx.copy(queryTags = ctx.queryTags ++ tags) 
def setFetchSize(size: Int): JDBCContext = ctx.copy(fetchSize = size) 
def setQueryTimeout(time: Option[Int]): JDBCContext = ctx.copy(queryTimeout = time) 
def setPreAction(action: Option[PreparedStatement => Unit]): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && 
!ctx.batch && ctx.statements.size == 1) 
ctx.copy(preAction = action) 
else 
throw new IllegalStateException("JDBCContex setting error: preAction not supported!") 
} 
def setPostAction(action: Option[PreparedStatement => Unit]): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && 
!ctx.batch && ctx.statements.size == 1) 
ctx.copy(postAction = action) 
else 
throw new IllegalStateException("JDBCContex setting error: preAction not supported!") 
} 
def appendDDLCommand(_statement: String, _parameters: Any*): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_EXEDDL) { 
ctx.copy( 
statements = ctx.statements ++ Seq(_statement), 
parameters = ctx.parameters ++ Seq(Seq(_parameters)) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: option not supported!") 
} 
def appendUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = { 
if (ctx.sqlType == JDBCContext.SQL_UPDATE && !ctx.batch) { 
ctx.copy( 
statements = ctx.statements ++ Seq(_statement), 
parameters = ctx.parameters ++ Seq(_parameters), 
returnGeneratedKey = ctx.returnGeneratedKey ++ (if (_returnGeneratedKey) Seq(Some(1)) else Seq(None)) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: option not supported!") 
} 
def appendBatchParameters(_parameters: Any*): JDBCContext = { 
if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch) 
throw new IllegalStateException("JDBCContex setting error: batch parameters only supported for SQL_UPDATE and batch = true!") 
var matchParams = true 
if (ctx.parameters != Nil) 
if (ctx.parameters.head.size != _parameters.size) 
matchParams = false 
if (matchParams) { 
ctx.copy( 
parameters = ctx.parameters ++ Seq(_parameters) 
) 
} else 
throw new IllegalStateException("JDBCContex setting error: batch command parameters not match!") 
} 
def setBatchReturnGeneratedKeyOption(returnKey: Boolean): JDBCContext = { 
if (ctx.sqlType != JDBCContext.SQL_UPDATE || !ctx.batch) 
throw new IllegalStateException("JDBCContex setting error: only supported in batch update commands!") 
ctx.copy( 
returnGeneratedKey = if (returnKey) Seq(Some(1)) else Nil 
) 
} 
def setQueryCommand(_statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
sqlType = JDBCContext.SQL_SELECT, 
batch = false 
) 
} 
def setDDLCommand(_statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
sqlType = JDBCContext.SQL_EXEDDL, 
batch = false 
) 
} 
def setUpdateCommand(_returnGeneratedKey: Boolean, _statement: String, _parameters: Any*): JDBCContext = { 
ctx.copy( 
statements = Seq(_statement), 
parameters = Seq(_parameters), 
returnGeneratedKey = if (_returnGeneratedKey) Seq(Some(1)) else Seq(None), 
sqlType = JDBCContext.SQL_UPDATE, 
batch = false 
) 
} 
def setBatchCommand(_statement: String): JDBCContext = { 
ctx.copy ( 
statements = Seq(_statement), 
sqlType = JDBCContext.SQL_UPDATE, 
batch = true 
) 
} 
} 
object JDBCEngine { 
import JDBCContext._ 
private def noExtractor(message: String): WrappedResultSet => Nothing = { (rs: WrappedResultSet) => 
throw new IllegalStateException(message) 
} 
def jdbcQueryResult[C[_] <: TraversableOnce[_], A]( 
ctx: JDBCContext, rowConverter: WrappedResultSet => A)( 
implicit cbf: CanBuildFrom[Nothing, A, C[A]]): C[A] = { 
ctx.sqlType match { 
case SQL_SELECT => { 
val params: Seq[Any] = ctx.parameters match { 
case Nil => Nil 
case p@_ => p.head 
} 
val rawSql = new SQLToCollectionImpl[A, NoExtractor](ctx.statements.head, params)(noExtractor("")) 
ctx.queryTimeout.foreach(rawSql.queryTimeout(_)) 
ctx.queryTags.foreach(rawSql.tags(_)) 
rawSql.fetchSize(ctx.fetchSize) 
implicit val session = NamedAutoSession(ctx.dbName) 
val sql: SQL[A, HasExtractor] = rawSql.map(rowConverter) 
sql.collection.apply[C]() 
} 
case _ => throw new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_SELECT'!") 
} 
} 
def jdbcExcuteDDL(ctx: JDBCContext): Try[String] = { 
if (ctx.sqlType != SQL_EXEDDL) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_EXEDDL'!")) 
} 
else { 
NamedDB(ctx.dbName) localTx { implicit session => 
Try { 
ctx.statements.foreach { stm => 
val ddl = new SQLExecution(statement = stm, parameters = Nil)( 
before = WrappedResultSet => {})( 
after = WrappedResultSet => {}) 
ddl.apply() 
} 
"SQL_EXEDDL executed succesfully." 
} 
} 
} 
} 
def jdbcBatchUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (ctx.statements == Nil) 
throw new IllegalStateException("JDBCContex setting error: statements empty!") 
if (ctx.sqlType != SQL_UPDATE) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!")) 
} 
else { 
if (ctx.batch) { 
if (noReturnKey(ctx)) { 
val usql = SQL(ctx.statements.head) 
.tags(ctx.queryTags: _*) 
.batch(ctx.parameters: _*) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
usql.apply[Seq]() 
Seq.empty[Long].to[C] 
} 
} 
} else { 
val usql = new SQLBatchWithGeneratedKey(ctx.statements.head, ctx.parameters, ctx.queryTags)(None) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
usql.apply[C]() 
} 
} 
} 
} else { 
Failure(new IllegalStateException("JDBCContex setting error: must set batch = true !")) 
} 
} 
} 
private def singleTxUpdateWithReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
val Some(key) :: xs = ctx.returnGeneratedKey 
val params: Seq[Any] = ctx.parameters match { 
case Nil => Nil 
case p@_ => p.head 
} 
val usql = new SQLUpdateWithGeneratedKey(ctx.statements.head, params, ctx.queryTags)(key) 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val result = usql.apply() 
Seq(result).to[C] 
} 
} 
} 
private def singleTxUpdateNoReturnKey[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
val params: Seq[Any] = ctx.parameters match { 
case Nil => Nil 
case p@_ => p.head 
} 
val before = ctx.preAction match { 
case None => pstm: PreparedStatement => {} 
case Some(f) => f 
} 
val after = ctx.postAction match { 
case None => pstm: PreparedStatement => {} 
case Some(f) => f 
} 
val usql = new SQLUpdate(ctx.statements.head,params,ctx.queryTags)(before)(after) 
Try { 
NamedDB(ctx.dbName) localTx {implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val result = usql.apply() 
Seq(result.toLong).to[C] 
} 
} 
} 
private def singleTxUpdate[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (noReturnKey(ctx)) 
singleTxUpdateNoReturnKey(ctx) 
else 
singleTxUpdateWithReturnKey(ctx) 
} 
private def noReturnKey(ctx: JDBCContext): Boolean = { 
if (ctx.returnGeneratedKey != Nil) { 
val k :: xs = ctx.returnGeneratedKey 
k match { 
case None => true 
case Some(k) => false 
} 
} else true 
} 
def noActon: PreparedStatement=>Unit = pstm => {} 
def multiTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
Try { 
NamedDB(ctx.dbName) localTx { implicit session => 
session.fetchSize(ctx.fetchSize) 
ctx.queryTimeout.foreach(session.queryTimeout(_)) 
val keys: Seq[Option[Any]] = ctx.returnGeneratedKey match { 
case Nil => Seq.fill(ctx.statements.size)(None) 
case k@_ => k 
} 
val sqlcmd = ctx.statements zip ctx.parameters zip keys 
val results = sqlcmd.map { case ((stm, param), key) => 
key match { 
case None => 
new SQLUpdate(stm, param, Nil)(noActon)(noActon).apply().toLong 
case Some(k) => 
new SQLUpdateWithGeneratedKey(stm, param, Nil)(k).apply().toLong 
} 
} 
results.to[C] 
} 
} 
} 
def jdbcTxUpdates[C[_] <: TraversableOnce[_]](ctx: JDBCContext)( 
implicit cbf: CanBuildFrom[Nothing, Long, C[Long]]): Try[C[Long]] = { 
if (ctx.statements == Nil) 
throw new IllegalStateException("JDBCContex setting error: statements empty!") 
if (ctx.sqlType != SQL_UPDATE) { 
Failure(new IllegalStateException("JDBCContex setting error: sqlType must be 'SQL_UPDATE'!")) 
} 
else { 
if (!ctx.batch) { 
if (ctx.statements.size == 1) 
singleTxUpdate(ctx) 
else 
multiTxUpdates(ctx) 
} else 
Failure(new IllegalStateException("JDBCContex setting error: must set batch = false !")) 
} 
} 
}

JDBCEngineDemo.scala

import java.io.File 
import java.io.FileOutputStream 
import java.io.InputStream 
import jdbccontext._ 
import configdbs._ 
import org.joda.time._ 
import scala.util._ 
import JDBCEngine._ 
import scalikejdbc._ 
object CrudDemo extends App { 
ConfigDBsWithEnv("dev").setup('h2) 
ConfigDBsWithEnv("dev").loadGlobalSettings() 
val dropSQL: String =""" 
      drop table members 
""" 
 
val createSQL: String =""" 
    create table members ( 
id serial not null primary key, 
name varchar(30) not null, 
description varchar(1000), 
birthday date, 
created_at timestamp not null, 
picture blob 
)""" 
 
var ctx = JDBCContext('h2) 
try { 
ctx = ctx.setDDLCommand(dropSQL) 
.appendDDLCommand(createSQL) 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
val resultCreateTable = jdbcExcuteDDL(ctx) 
resultCreateTable match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
} 
val insertSQL = "insert into members(name,birthday,description,created_at,picture) values (?, ?, ?, ?, ?)" 
val dateCreated = DateTime.now 
import java.io.FileInputStream 
val picfile = new File("/users/tiger/Nobody.png") 
val fis = new FileInputStream(picfile) 
ctx = JDBCContext('h2) 
try { 
ctx = ctx.setBatchCommand(insertSQL).appendBatchParameters( 
"John",new LocalDate("2008-03-01"),"youngest user",dateCreated,None).appendBatchParameters( 
"peter", None, "no birth date", dateCreated, fis) 
.appendBatchParameters( 
"susan", None, "no birth date", dateCreated, None) 
.setBatchReturnGeneratedKeyOption(JDBCContext.RETURN_GENERATED_KEYVALUE) 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
var resultInserts = jdbcBatchUpdate(ctx) 
resultInserts match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
} 
val updateSQL = "update members set description = ? where id < ?" 
ctx = JDBCContext('h2) 
try { 
ctx = ctx.setUpdateCommand(JDBCContext.RETURN_GENERATED_KEYVALUE,insertSQL, 
"max", None, "no birth date", dateCreated, None) 
.appendUpdateCommand(JDBCContext.RETURN_UPDATED_COUNT, updateSQL, "id++", 10) 
.appendUpdateCommand(JDBCContext.RETURN_UPDATED_COUNT,"delete members where id = 1") 
} 
catch { 
case e: Exception => println(e.getMessage) 
} 
var resultUpdates = jdbcTxUpdates[Vector](ctx) 
resultUpdates match { 
case Success(msg) => println(msg) 
case Failure(err) => println(s"${err.getMessage}") 
} 
//data model 
case class Member( 
id: Long, 
name: String, 
description: Option[String] = None, 
birthday: Option[LocalDate] = None, 
createdAt: DateTime, 
picture: InputStream) 
//data row converter 
val toMember = (rs: WrappedResultSet) => Member( 
id = rs.long("id"), 
name = rs.string("name"), 
description = rs.stringOpt("description"), 
birthday = rs.jodaLocalDateOpt("birthday"), 
createdAt = rs.jodaDateTime("created_at"), 
picture = rs.binaryStream("picture") 
) 
ctx = JDBCContext('h2) 
ctx = ctx.setQueryCommand("select * from members").setQueryTimeout(Some(1000)) 
val vecMember: Vector[Member] = jdbcQueryResult[Vector,Member](ctx,toMember) 
val buffer = new Array[Byte](1024) 
vecMember.foreach {row => 
println(s"id: ${row.id} name: ${row.name}") 
println(s"name: ${row.name}") 
if (row.picture == null) 
println("picture empty") 
else { 
val fname = s"/users/tiger/pic${row.id}.png" 
val file = new File(fname) 
val output = new FileOutputStream(file) 
println(s"saving picture to $fname") 
row.picture.available() 
while (row.picture.read(buffer) > 0) { 
output.write(buffer) 
} 
output.close() 
} 
} 
}

 

 

 

 

 

 

 

 

 

 

 

原创文章,作者:奋斗,如若转载,请注明出处:https://blog.ytso.com/12813.html

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