Question

ETL for M：M

我们在RDBMS中有以下表格：

ExternalMessageConfig（id，name，...）;
ExternalMessageDataConfig（id，dataname，...）;
ExternalMessageConfigMapping（messageConfigId，dataConfigId）（M：M）（链接表）。

我们创建了2个顶点：ExternalMessageConfig和ExternalMessageDataConfig。

我们在ExternalMessageConfig中创建了：out_ExternalMessageDataConfig TYPE LINKLIST来填充ExternalMessageDataConfig。

问题：

如何编写ETL来填充out_ExternalMessageDataConfig？

或者

如何编写创建CREATE LINK查询？

ORIENT DB版本：2.0.13

Answer 1

目标是：一旦将表从RDBMS导入到OrientDB（通过ETL工具），以下脚本允许您在具有多对多关系的各种实体之间创建链接（目前ETL不可能）。

默认方案涉及以下步骤/条件：

1）运行ETL导入3个表：表1（left_table），表2（right_table），表3（mm-table包含关系m：n的id）

2）在orient数据库中，将有三个包含数据的类

3）运行代码，该代码将创建连接left_table的边 - ＆gt; table_right，取消mm-table现在无用的类，取消left_table和right_table的字段'id'，因为在OrientDB id中不需要。

<强> JAVASCRIPT

Function with parameters: "leftTable" , "rightTable" , "mmTable" , "nameIdLeft" , "nameIdRight" , "nameEdge"

var g=orient.getGraphNoTx();
g.command("sql","CREATE CLASS " + nameEdge + " EXTENDS E");
var MM_table = g.command("sql","select from " + mmTable);
for(i=0;i<MM_table.length;i++){
var recordMM=g.command("sql","select " + nameIdLeft + " , " + nameIdRight + " from "+ MM_table[i].getId());
var idLeft=recordMM[0].getProperty(nameIdLeft);
var idRight=recordMM[0].getProperty(nameIdRight);
var left=g.command("sql","select from " + leftTable + " where " + nameIdLeft + " = " + idLeft);
var right=g.command("sql","select from " + rightTable + " where " + nameIdRight + " = " + idRight);
g.command("sql","create edge Left_Right from " + left[0].getId() + " to " + right[0].getId());
}
g.command("sql","drop class " + mmTable + " unsafe");
g.command("sql","UPDATE " + leftTable + " REMOVE " + nameIdLeft);
g.command("sql","UPDATE " + rightTable + " REMOVE " + nameIdRight);

来自工作室的电话：

select myFunction("Animal","Person","MMtable","idAnimal","idPerson","Left_Right")

<强> JAVA

public class ManyToMany {

    static final String REMOTE      = "remote:localhost/";
    static final String NOMEDB      = "MoltiAmolti";
    static final String CURRENTPATH = REMOTE + NOMEDB;

    public static void main(String[] args) throws IOException {

        OServerAdmin serverAdmin = new OServerAdmin(CURRENTPATH).connect("root", "root");

        OrientGraphNoTx g = new OrientGraphFactory(CURRENTPATH).getNoTx();

        createEdgeManyToMany(g, "Animal", "Person", "mmTable", "idAnimal", "idPerson", "Left_Right");
    }


    public static void createEdgeManyToMany (OrientGraphNoTx  g, String leftTable, String rightTable, String mmTable, 
                         String nameIdLeft, String nameIdRight, String nameEdge){

        System.out.println("Start processing...");

        //query on mmTable to save 2 id
        String getMMvertex = "select from "+mmTable;
        Iterable<Vertex> mm_vertex = g.command(new OSQLSynchQuery<Vertex>(getMMvertex)).execute();
        List<OrientVertex> listaVertex = new ArrayList<OrientVertex>();
        CollectionUtils.addAll(listaVertex, mm_vertex.iterator());

        //for each record
        String idLeft = ""; 
        String idRight = "";
        Iterable<Vertex> vertexLeft;
        Iterable<Vertex> vertexRight;
        String queryGetLeft = "";
        String queryGetRight = "";
        String queryEdge = "";
        String tmpIdleft = "";
        String tmpIdRight = "";

        //create class edge
        OClass edge = g.createEdgeType(nameEdge, "E");

        for (int i = 0; i<listaVertex.size(); i++) {
            System.out.println("Record Many-to-Many n°"+(i+1));
            idLeft = listaVertex.get(i).getProperty(nameIdLeft).toString();
            idRight = listaVertex.get(i).getProperty(nameIdRight).toString();

            queryGetLeft = "SELECT FROM " + leftTable + " WHERE " + nameIdLeft + " = " + idLeft;
            vertexLeft = g.command(new OCommandSQL(queryGetLeft)).execute();

            queryGetRight = "SELECT FROM " + rightTable + " WHERE " + nameIdRight + " = " + idRight;
            vertexRight = g.command(new OCommandSQL(queryGetRight)).execute();

            //create edge from vertex-left to vertex-right
            tmpIdleft = vertexRight.iterator().next().getId().toString();
            tmpIdRight = vertexLeft.iterator().next().getId().toString();
            queryEdge = "CREATE EDGE "+nameEdge+" FROM "+tmpIdleft+" TO "+tmpIdRight;
            g.command(new OCommandSQL(queryEdge)).execute();

            System.out.println("   - Created edge: "+queryEdge);
        }

        //remove id from origin vertex now useless
        g.command(new OCommandSQL("DROP PROPERTY "+leftTable+"."+nameIdLeft+" FORCE")).execute();
        g.command(new OCommandSQL("UPDATE "+leftTable+" REMOVE "+nameIdLeft+"")).execute();
        g.command(new OCommandSQL("DROP PROPERTY "+rightTable+"."+nameIdRight+" FORCE")).execute();
        g.command(new OCommandSQL("UPDATE "+rightTable+" REMOVE "+nameIdRight+"")).execute();
        System.out.println("Update old vertex eliminating id fields");
        g.command(new OCommandSQL("DROP class "+mmTable+" unsafe")).execute();
        System.out.println("Remove class many-to-many");

        System.out.println("End!"); 
        g.shutdown();
    }
}

修改

'WHITOUT EDGE BUT with LINKLIST'

好的，所以你想要拥有它的结果应该是这样的：

代码没有太多改动，不同的是添加到LeftTable中的Linklist属性并创建了指向rightTable的链接。

JAVA CHANGES

public static void createEdgeManyToMany (OrientGraphNoTx g, String leftTable, String rightTable, String mmTable, String nameIdLeft, String nameIdRight, String link) { System.out.println("Start processing..."); //query on mmTable to save 2 id String getMMvertex = "select from "+mmTable; Iterable<Vertex> mm_vertex = g.command(new OSQLSynchQuery<Vertex>(getMMvertex)).execute(); List<OrientVertex> listaVertex = new ArrayList<OrientVertex>(); CollectionUtils.addAll(listaVertex, mm_vertex.iterator()); //for each record String idLeft = ""; String idRight = ""; Iterable<Vertex> vertexLeft; Iterable<Vertex> vertexRight; String queryGetLeft = ""; String queryGetRight = ""; String queryEdge = ""; String tmpIdleft = ""; String tmpIdRight = ""; String queryLink = ""; boolean created = false; for (int i = 0; i<listaVertex.size(); i++) { System.out.println("Record Many-to-Many n°"+(i+1)); idLeft = listaVertex.get(i).getProperty(nameIdLeft).toString(); idRight = listaVertex.get(i).getProperty(nameIdRight).toString(); queryGetLeft = "SELECT FROM " + leftTable + " WHERE " + nameIdLeft + " = " + idLeft; vertexLeft = g.command(new OCommandSQL(queryGetLeft)).execute(); queryGetRight = "SELECT FROM " + rightTable + " WHERE " + nameIdRight + " = " + idRight; vertexRight = g.command(new OCommandSQL(queryGetRight)).execute(); //create edge from vertex-left to vertex-right tmpIdleft = vertexLeft.iterator().next().getId().toString(); tmpIdRight = vertexRight.iterator().next().getId().toString(); //add in the schema class the property link if (!created) { OClass leftTableClass = g.getRawGraph().getMetadata().getSchema().getClass(leftTable); OClass rightTableclass = g.getRawGraph().getMetadata().getSchema().getClass(rightTable); leftTableClass.createProperty(link, OType.LINKLIST, rightTableclass); created = true; } //without edge but with link queryLink = "update "+tmpIdleft+" ADD "+link+" = "+tmpIdRight; g.command(new OCommandSQL(queryLink)).execute(); System.out.println(" - Created link: "+queryLink); } //remove id from origin vertex now useless g.command(new OCommandSQL("DROP PROPERTY "+leftTable+"."+nameIdLeft+" FORCE")).execute(); g.command(new OCommandSQL("UPDATE "+leftTable+" REMOVE "+nameIdLeft+"")).execute(); g.command(new OCommandSQL("DROP PROPERTY "+rightTable+"."+nameIdRight+" FORCE")).execute(); g.command(new OCommandSQL("UPDATE "+rightTable+" REMOVE "+nameIdRight+"")).execute(); System.out.println("Update old vertex eliminating id fields"); g.command(new OCommandSQL("DROP class "+mmTable+" unsafe")).execute(); System.out.println("Remove class many-to-many"); System.out.println("End!"); g.shutdown(); }

JAVASCRIPT CHANGES

参数：leftTable，rightTable，mmTable，nameIdLeft，nameIdRight，nameLink

var g=orient.getGraphNoTx(); g.command("sql","CREATE PROPERTY " + leftTable + "." + nameLink + " linklist " + rightTable); var MM_table = g.command("sql","select from " + mmTable); for(i=0;i<MM_table.length;i++){ var recordMM=g.command("sql","select " + nameIdLeft + " , " + nameIdRight + " from "+ MM_table[i].getId()); var idLeft=recordMM[i].getProperty(nameIdLeft); var idRight=recordMM[i].getProperty(nameIdRight); var left=g.command("sql","select from " + leftTable + " where " + nameIdLeft + " = " + idLeft); var right=g.command("sql","select from " + rightTable + " where " + nameIdRight + " = " + idRight); g.command("sql","update " + left[0].getId() + " add " + nameLink + " = [ " + right[0].getId()+ " ]"); } g.command("sql","drop class " + mmTable + " unsafe"); g.command("sql","UPDATE " + leftTable + " REMOVE " + nameIdLeft); g.command("sql","UPDATE " + rightTable + " REMOVE " + nameIdRight);

东方ETL很多很多

1 个答案: