如何从表中检索一百万行并将其插入另一个表？

Question

我有一个返回一百万行的SQL连接查询.

而SQL QUERY是:

 SELECT d.* 
 FROM snomed_conceptdata c, snomed_descriptiondata d 
 WHERE c.active = 1 and conceptid = c.id AND d.active = 1

我如何检索此数据并将其插入另一个表而不会遇到内存堆空间错误.我目前使用的是Mysql数据库.

我目前的代码:

package Snomed.Snomed;

import java.sql.PreparedStatement;
import java.sql.ResultSet;


import catalog.Root;

public class Snomedinfo {

    public void snomedinfoinsert()
    {
    Root oRoot = null;
    ResultSet oRsSelect = null;
    PreparedStatement oPrStmt = null;
    PreparedStatement oPrStmt2 = null;
    PreparedStatement oPrStmtSelect = null;
    String strSql = null;


    ResultSet oRs = null;
    String refid = null;
    String id = null;
    String effectivetime = null;
    String active = null;
    String moduleid = null;
    String conceptid = null;
    String languagecode = null;
    String typeid = null;
    String term = null;
    String caseSignificanceid = null;

    try{
    oRoot = Root.createDbConnection(null);
    strSql = "SELECT d.* FROM snomed_conceptdata c, snomed_descriptiondata d WHERE c.active = 1 and conceptid = c.id AND d.active = 1  "; //this query returns a million rows.


    oPrStmt2 = oRoot.con.prepareStatement(strSql);

    oRs = oPrStmt2.executeQuery();

    String sql = "INSERT INTO snomedinfo_date (refid,id,effectivetime,active,moduleid,conceptid,languagecode,typeid,term,caseSignificanceid) VALUES( ?, ?, ?,?,?,?,?,?,?,?)";
    oPrStmt = oRoot.con.prepareStatement(sql);





        while (oRs.next())
        {
            refid = Root.TrimString(oRs.getString("refid")); 
            id = Root.TrimString(oRs.getString("id"));
            effectivetime = Root.TrimString(oRs.getString("effectivetime"));
            active = Root.TrimString(oRs.getString("active"));
            moduleid = Root.TrimString(oRs.getString("moduleid"));
            conceptid = Root.TrimString(oRs.getString("conceptid"));
            languagecode = Root.TrimString(oRs.getString("languagecode"));
            typeid = Root.TrimString(oRs.getString("typeid"));
            term = Root.TrimString(oRs.getString("term"));
            caseSignificanceid = Root.TrimString(oRs.getString("caseSignificanceid"));  


            oPrStmt.setString(1, refid);
            oPrStmt.setString(2, id);
            oPrStmt.setString(3, effectivetime);
            oPrStmt.setString(4, active);
            oPrStmt.setString(5, moduleid);
            oPrStmt.setString(6, conceptid);
            oPrStmt.setString(7, languagecode);
            oPrStmt.setString(8, typeid );
            oPrStmt.setString(9, term);
            oPrStmt.setString(10, caseSignificanceid);
             oPrStmt.executeUpdate();
        }






    }

    catch (Exception e) {
        e.printStackTrace();

    }

    finally {

        oRsSelect = Root.EcwCloseResultSet(oRsSelect);
        oRs = Root.EcwCloseResultSet(oRs);
        oPrStmt = Root.EcwClosePreparedStatement(oPrStmt);
        oPrStmt = Root.EcwClosePreparedStatement(oPrStmt2);
        oPrStmt = Root.EcwClosePreparedStatement(oPrStmtSelect);
        oRoot = Root.closeDbConnection(null, oRoot);
    }


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

      Snomedinfo a = new Snomedinfo();
      a .snomedinfoinsert();

      }


}

Answer 1

在mysql中,您可以使用create select,或者如果表已经存在insert select

create my_table_copy
SELECT d.* 
FROM snomed_conceptdata c
INNER JOIN snomed_descriptiondata d ON c.active = 1 
          and conceptid = c.id 
              AND d.active = 1

要么

insert into   your_table  (col1, col2, col3)
SELECT d.col1, d.col2, d.col3 
FROM snomed_conceptdata c
INNER JOIN snomed_descriptiondata d ON c.active = 1 
          and conceptid = c.id 
              AND d.active = 1.51

确保你有足够的磁盘空间