总览

生成运行时env

生成表环境

接上数据流，数据流数据生成表

把数据库中sink保存数据的表，在flink中生成一遍（相当于把flink生成的表，绑定到数据库中的表），配上数据库连接信息，并执行，及注册

查询表，可以根据注册表名查询

插入表，可以根据生成的flink表进行数据插入

完整案例：

import org.apache.flink.streaming.api.scala._import org.apache.flink.table.api.bridge.scala._import org.apache.flink.table.api._import org.apache.flink.table.api.{DataTypes, Table}import org.apache.flink.table.descriptors._object SqlReadMysql {  def main(args: Array[String]): Unit = {    // creat env    val bsEnv = StreamExecutionEnvironment.getExecutionEnvironment    //parallelism    bsEnv.setParallelism(1)    //set env    val bsSetting = EnvironmentSettings      .newInstance()      .useBlinkPlanner()      .inStreamingMode()      .build()    //create table env    val bsTableEnv = StreamTableEnvironment.create(bsEnv, bsSetting)    //create ds    val dataStream = bsEnv.fromElements(Tuple2("01","lisi" ))    val table1 = bsTableEnv.fromDataStream(dataStream)    //create table    val sinkDDL =      """        |create table student2_flink (        |code varchar(20) null,        |name varchar(20) null        |)with(        |'connector.type'='jdbc',        |'connector.url'='jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC',        |'connector.table'='student2',        |'connector.driver'='com.mysql.jdbc.Driver',        |'connector.username'='root',        |'connector.password'='root'        |)        |""".stripMargin    println(sinkDDL)    // execute the create table sql    bsTableEnv.executeSql(sinkDDL)    //register table    val myStudent = bsTableEnv.from("student2_flink")    //execute query    val result = bsTableEnv.sqlQuery(s"select * from $myStudent")    result.toRetractStream[(String, String)].print()    //insert data    table1.executeInsert("student2_flink")    //execute    bsEnv.execute()  }}

POM文件：

    4.0.0    org.sinopharm.gksk    gksk-bigdata    1.0-SNAPSHOT    gksk-bigdata        http://www.example.com            UTF-8        1.8        1.8        1.2.17        1.7.25        1.7.25                                    org.apache.flink            flink-java            1.14.4                            org.apache.flink            flink-streaming-java_2.12            1.14.4                                    org.apache.flink            flink-scala_2.12            1.14.4                            org.apache.flink            flink-streaming-scala_2.12            1.14.4                                    org.apache.flink            flink-table-api-scala-bridge_2.12            1.14.4                            org.apache.flink            flink-table-planner_2.12            1.14.4                            org.apache.flink            flink-table-planner-blink_2.12            1.12.0            provided                            org.apache.flink            flink-table-common            1.14.4                            org.apache.flink            flink-csv            1.14.4                                    org.apache.flink            flink-connector-kafka_2.12            1.14.4                                    org.apache.flink            flink-statebackend-rocksdb_2.12            1.14.4                            org.apache.flink            flink-connector-jdbc_2.12            1.14.4                            mysql            mysql-connector-java            8.0.16                                    org.apache.flink            flink-clients_2.12            1.14.4                                    org.apache.flink            flink-runtime-web_2.12            1.14.4            runtime                                    junit            junit            4.11            test                                    org.slf4j            slf4j-log4j12            ${slf4j.version}            runtime                            log4j            log4j            ${log4j.version}            runtime                                                    src/main/java                                        src/main/scala                                                                                org.apache.maven.plugins                maven-compiler-plugin                3.1                                    1.8                    1.8                                                                    net.alchim31.maven                scala-maven-plugin                3.2.2                                                            compiletestCompile                                                                                    

Could not instantiate the executor. Make sure a planner module is on the classpath

原因：pom文件中缺少 planner

解决办法：添加

    org.apache.flink    flink-table-planner_2.12    1.14.4

ps：注意有时候 配置两个planner也会报错

flinksql 连接mysql报错 JDBC-Class not found. - com.mysql.jdbc.Driver

原因：缺少mysql的jar包

解决：pom文件添加：

    mysql    mysql-connector-java    8.0.16

open() failed.The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

原因：URL没有指定时区，jdbc 6.0以上都有这个问题

解决：在URL后边加时区

'connector.url'='jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC',

 

• useUnicode=true  表示使用Unicode字符，因此可以使用中文
• characterEncoding=utf8  设置编码方式
• useSSL=true   设置安全连接
• serverTimezone=UTC    设置全球标准时间
   

open() failed.Cannot load connection class because of underlying exception: com.mysql.cj.exceptions.WrongArgumentException: Malformed database URL, failed to parse the main URL sections.

原因：连接的URL写错了

解决：好好看看，字符 、格式

来源地址：https://blog.csdn.net/hzp666/article/details/128796575