datax 抽取多表各个字段汇总

要抽取多个表的各个字段并进行汇总，可以使用 DataX 的 join 插件。具体步骤如下：

1. 在配置文件中，先分别配置好多个数据源的读取器和写入器。
2. 然后在 job 中配置 join 插件，指定要关联的表和字段。
3. 在 join 插件中，可以通过设置 join 类型、关联条件和需要输出的字段等来完成数据的汇总。

示例配置文件如下：

{
  "job": {
    "content": [
      {
        "reader": {
          "name": "mysqlreader1",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["id", "name"],
            "where": "id > 100",
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.1:3306/test",
                "table": ["table1"]
              }
            ]
          }
        },
        "writer": {
          "name": "mysqlwriter",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["id", "name"],
            "preSql": "truncate table table3",
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.1:3306/test",
                "table": "table3"
              }
            ]
          }
        }
      },
      {
        "reader": {
          "name": "mysqlreader2",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["id", "age"],
            "where": "age > 18",
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.2:3306/test",
                "table": ["table2"]
              }
            ]
          }
        },
        "writer": {
          "name": "mysqlwriter",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["id", "age"],
            "preSql": "truncate table table3",
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.1:3306/test",
                "table": "table3"
              }
            ]
          }
        }
      },
      {
        "setting": {
          "speed": {
            "channel": 2
          }
        },
        "reader": {
          "name": "mysqlreader",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["table1.id", "table1.name", "table2.age"],
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.1:3306/test",
                "table": ["table1"]
              },
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.2:3306/test",
                "table": ["table2"]
              }
            ]
          }
        },
        "writer": {
          "name": "mysqlwriter",
          "parameter": {
            "username": "root",
            "password": "123456",
            "column": ["id", "name", "age"],
            "preSql": "truncate table table3",
            "connection": [
              {
                "jdbcUrl": "jdbc:mysql://192.168.1.1:3306/test",
                "table": "table3"
              }
            ]
          }
        },
        "plugin": [
          {
            "name": "join",
            "parameter": {
              "type": "left",
              "joinKey": "table1.id=table2.id",
              "outputKeys": "table1.id,table1.name,table2.age"
            }
          }
        ]
      }
    ],
    "setting": {
      "errorLimit": {
        "record": 0,
        "percentage": 0.02
      }
    }
  }
}

在以上配置文件中，先分别配置了两个数据源的读取器和写入器，然后在第三个任务中配置了 join 插件来完成数据的汇总。其中 join 插件的参数包括 join 类型、关联条件和需要输出的字段等。最后将结果输出到另一个数据源中。