【java/oralce/sql】往一张仅有id，名称，创建时间三个字段的表中插入百万数据需要多久？1分26秒

代码下载：https://files.cnblogs.com/files/xiandedanteng/fastfilltable20191222.rar

表testtb18的结构如下：

CREATE TABLE testtb18
(
    id NUMBER not null primary key,
    name NVARCHAR2() not null,
    createtime ) not null
)

三个字段，正好是常用的number，nvarcha2，timestamp类型。

用java程序创建这表表的代码如下：

/**
 * 数据库连接参数
 * @author 逆火
 *
 * 2019年11月16日 上午8:09:24
 */
public final class DBParam {
    public final static String Driver = "oracle.jdbc.driver.OracleDriver";
    ::orcl";
    public final static String User = "ufo";
    ";
}

package com.hy.fastfilltable;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.apache.log4j.Logger;

// Used to create a table in oracle
public class TableCreater {
    private static Logger log = Logger.getLogger(TableCreater.class);
    private final String table="testtb18";

    public boolean createTable() {
        Connection conn = null;
        Statement stmt = null;

        try{
            Class.forName(DBParam.Driver).newInstance();
            conn = DriverManager.getConnection(DBParam.DbUrl, DBParam.User, DBParam.Pswd);
            stmt = conn.createStatement();

            String createTableSql=getCreateTbSql(table);
            stmt.execute(createTableSql);

            if(isTableExist(table,stmt)==true) {
                log.info("Table:'"+table+"' created.");
                return true;
            }

        } catch (Exception e) {
            System.out.print(e.getMessage());
        } finally {
            try {
                stmt.close();
                conn.close();
            } catch (SQLException e) {
                System.out.print("Can't close stmt/conn because of " + e.getMessage());
            }
        }

        return false;
    }

    /**
     * Get a table's ddl
     * @param table
     * @return
     */
    private String getCreateTbSql(String table) {
        StringBuilder sb=new StringBuilder();
        sb.append("CREATE TABLE "+table);
        sb.append("(");
        sb.append("id NUMBER not null primary key,");
        sb.append("name NVARCHAR2(60) not null,");
        sb.append("createtime TIMESTAMP (6) not null");
        sb.append(")");

        return sb.toString();
    }

    // Execute a sql
    //private int executeSql(String sql,Statement stmt) throws SQLException {
    //    return stmt.executeUpdate(sql);
    //}

    // If a table exists
    private boolean isTableExist(String table,Statement stmt) throws SQLException {
        String sql="SELECT COUNT (*) as cnt FROM ALL_TABLES WHERE table_name = UPPER('"+table+"')";

        ResultSet rs = stmt.executeQuery(sql);

        while (rs.next()) {
            int count = rs.getInt("cnt");
            return count==1;
        }

        return false;
    }

    // Entry point
    public static void main(String[] args) {
        TableCreater tc=new TableCreater();
        tc.createTable();
    }
}

现在我想就往这张表里添值，到一百万条记录，可以这么做：

package com.hy.fastfilltable;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.DecimalFormat;

import org.apache.log4j.Logger;

import com.hy.DBParam;

public class FastTableFiller {
    private static Logger log = Logger.getLogger(FastTableFiller.class);

    private final String Table="testtb18";
    private final int Total=1000000;

    public boolean fillTable() {
        Connection conn = null;
        Statement stmt = null;

        try{
            Class.forName(DBParam.Driver).newInstance();
            conn = DriverManager.getConnection(DBParam.DbUrl, DBParam.User, DBParam.Pswd);
            conn.setAutoCommit(false);
            stmt = conn.createStatement();

            long startMs = System.currentTimeMillis();
            clearTable(stmt,conn);
            fillDataInTable(stmt,conn);

            long endMs = System.currentTimeMillis();
            log.info("It takes "+ms2DHMS(startMs,endMs)+" to fill "+toEastNumFormat(Total)+" records to table:'"+Table+"'.");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                stmt.close();
                conn.close();
            } catch (SQLException e) {
                System.out.print("Can't close stmt/conn because of " + e.getMessage());
            }
        }

        return false;
    }

    private void clearTable(Statement stmt,Connection conn) throws SQLException {
        stmt.executeUpdate("truncate table "+Table);
        conn.commit();
        log.info("Cleared table:'"+Table+"'.");
    }

    private void fillDataInTable(Statement stmt,Connection conn) throws SQLException {
        StringBuilder sb=new StringBuilder();
        sb.append(" Insert into "+Table);
        sb.append(" select rownum,dbms_random.string('*',50),sysdate from dual ");
        sb.append(" connect by level<="+Total);
        sb.append(" order by dbms_random.random");

        String sql=sb.toString();
        stmt.executeUpdate(sql);
        conn.commit();

    }

    // 将整数在万分位以逗号分隔表示
    public static String toEastNumFormat(long number) {
        DecimalFormat df = new DecimalFormat("#,####");
        return df.format(number);
    }

    // change seconds to DayHourMinuteSecond format
    private static String ms2DHMS(long startMs, long endMs) {
        String retval = null;
        long secondCount = (endMs - startMs) / 1000;
        String ms = (endMs - startMs) % 1000 + "ms";

        long days = secondCount / (60 * 60 * 24);
        long hours = (secondCount % (60 * 60 * 24)) / (60 * 60);
        long minutes = (secondCount % (60 * 60)) / 60;
        long seconds = secondCount % 60;

        if (days > 0) {
            retval = days + "d" + hours + "h" + minutes + "m" + seconds + "s";
        } else if (hours > 0) {
            retval = hours + "h" + minutes + "m" + seconds + "s";
        } else if (minutes > 0) {
            retval = minutes + "m" + seconds + "s";
        } else {
            retval = seconds + "s";
        }

        return retval + ms;
    }

    // Entry point
    public static void main(String[] args) {
        FastTableFiller f=new FastTableFiller();
        f.fillTable();
    }
}

执行效果还不错：

2019-12-22 15:21:02,412 INFO[main]-Cleared table:'testtb18'.
2019-12-22 15:22:28,669 INFO[main]-It takes 1m26s268ms to fill 100,0000 records to table:'testtb18'.

注意：插一千万数据就会报oom异常，怎么解决请大家自行考虑，我暂时没这样的需求。

再看看表中情况;

--END-- 2019年12月22日15:35:27