使用JAVA在HANA中插入数组 [英] Insert array in HANA with JAVA

问题描述

我有一个对象的数组列表，并试图将列表插入HANA。所以我的插入代码看起来像

I am having an arraylist of objects and trying to insert the list into HANA. So my insert code looks like

PreparedStatement stmt = conn
        .prepareStatement("INSERT INTO SCHEMA.TABLE VALUES"
                + " (?, ?, ?, ?, ?, ?, ?, ARRAY("+"1,2,3"+")");

for (int i = 1; i <= ITERATION_MAX; i++) {

    stmt.setInt(1, listofdata.get(i).get_id());
    stmt.setInt(2, listofdata.get(i).get_name());
    stmt.setInt(3, listofdata.get(i).get_place());
    stmt.setInt(4, listofdata.get(i).get_year());
    stmt.setInt(5, listofdata.get(i).get_day());
    stmt.setInt(6, listofdata.get(i).get_rollno());
    stmt.setInt(7, listofdata.get(i).get_main_subject());
    stmt.setArray(8, listofdata.get(i).get_elective());

    stmt.addBatch();

}

   stmt.executeBatch();

$ b listofdata.get（i）.get_elective（）

返回一个整数数组。

但是这不工作。根据我的程序ARRAY函数每次被调用，但为什么不插入到HANA数据库。一段时间后，我理解，我必须转换JAVA数组到HANA数组。如何将java数组转换为HANA数组。

But this does not work.According to my program ARRAY function is called each time but why does not it inserting into HANA Database.So after a while I understood that I have to convert JAVA Array into HANA Array.How can I convert a java Array to HANA Array. Any help is appreciated.

推荐答案

@RKR确定，这里你有你的例子：

@RKR ok, here you have your example:

     /*
     * We're goin to insert several arrays into the HANA table, 
     * with different lengths
     * 
     * let's assume we already got a table like this
     * CREATE COLUMN TABLE T3 ( ID INT PRIMARY KEY, C1 INT ARRAY );
     */

    Integer[][] myarr ={ {1}, {1,2}, {1,2,3,4,5}, {1,2}, {1,2,3} };

    String testSection = "Insert Arrays one by one";
    stopWatch.start(testSection);
    myDBconn.setAutoCommit(false);

    Statement stmt = myDBconn.createStatement();

    stmt = myDBconn.createStatement();

    stmt.execute("TRUNCATE TABLE DEVDUDE.T3");

    // loop over our array of arrays and visit each once
    for (int i = 0 ; i < (myarr.length); i++) {
        int curr_length = myarr[i].length;

        String arrayFunction = "ARRAY (";

        for (int j = 0; j < (curr_length); j++){

            arrayFunction = arrayFunction.concat(myarr[i][j].toString()) ;

            // add comma if this is not the last element
            if (j < (curr_length - 1)){
                arrayFunction = arrayFunction.concat(", ") ;
            }
        }

        arrayFunction = arrayFunction + ")" ;
        // now the arrayFunction should loook like this
        // ARRAY ( ..., .... ,... )

        String insCMD = "INSERT INTO T3 (id, c1) "
                        + " VALUES (" + i + ", " 
                        + arrayFunction 
                        + " ) ";

        System.out.println(insCMD);
        int affectedRows = stmt.executeUpdate(insCMD);

        System.out.println("Loop round " + i
                    + ", last affected row count " + affectedRows);
        }


    myDBconn.commit();
    stmt.close();
    stmt = null;

不，此代码不清除INSERT语句的输入但是这样做是为了避免SQL注入。

And no, this code does not sanitise the input to the INSERT statement but that has to be done in order to avoid SQL injection.

当我运行代码，这是什么打印：

When I run the code this is what gets printed:

INSERT INTO T3 (id, c1)  VALUES (0, ARRAY (1) ) 
Loop round 0, last affected row count 1
INSERT INTO T3 (id, c1)  VALUES (1, ARRAY (1, 2) ) 
Loop round 1, last affected row count 1
INSERT INTO T3 (id, c1)  VALUES (2, ARRAY (1, 2, 3, 4, 5) ) 
Loop round 2, last affected row count 1
INSERT INTO T3 (id, c1)  VALUES (3, ARRAY (1, 2) ) 
Loop round 3, last affected row count 1
INSERT INTO T3 (id, c1)  VALUES (4, ARRAY (1, 2, 3) ) 
Loop round 4, last affected row count 1

表上的SELECT返回：

And a SELECT on the table returns:

ID  C1           
0   1            
1   1, 2         
2   1, 2, 3, 4, 5
3   1, 2         
4   1, 2, 3      

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