前期准备

Flink提供了JDBC连接器，需要添加如下依赖

<!--选择自己需要的版本号-->
<dependency>
	<groupId>org.apache.flink</groupId>
	<artifactId>flink-connector-jdbc_${scala.binary.version}</artifactId>
	<version>${flink.version}</version>
</dependency>
<!--还是通过jdbc去连接数据库,所以需要加上对应的驱动器-->
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>${mysql-connector.version}</version>
</dependency>

连接测试

测试代码如下

package org.eects;

import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.types.Row;
import org.apache.flink.connector.jdbc.JdbcInputFormat;

/**
 * <p>
 * 数据库读取
 * </p>
 *
 * @author 13706
 * @since 2021/4/9
 */
public class JdbcReader {
    public static void main(String[] args) throws Exception{
        String sql = "select EqDeg from EqInfo";
		String drivername = "com.mysql.cj.jdbc.Driver";//根据建议修改为这个
		String url = "jdbc:mysql://host:3306/database";
		String user = "root"
		String password = "yourpassword"
		
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        
        DataStream<Row> data = env.createInput(JdbcInputFormat.buildJdbcInputFormat()
                .setDrivername(drivername)
                .setDBUrl(url)
                .setUsername(user)
                .setPassword(password)
                .setQuery(sql)
                .setRowTypeInfo(new RowTypeInfo(BasicTypeInfo.FLOAT_TYPE_INFO))//此处的EqDeg是float类型
                .finish());
        //输出测试是否获取到数据
        data.print();
        env.execute();
    }
}

输出结果如下

3>6.0