导语

因为项目中要做跨数据源的数据分析功能，所以使用Presto这个开源框架。但是使用Presto的时候需要指定当前表所在的数据库类型和数据库名，所以需要对SQL语句中的表名进行捕获和替换。

一.探索过程

首先使用的是HiveParse这个工具，修改了语法树中的表名，但是好像没有提供由语法树得到SQL语句的方法。之后又使用了Druid的SQL解析器，但是这个框架结构很复杂，看了一天也没弄清处解析的流程。后来看到这篇博客JAVA - Sql解析工具fdb-sql-parser简单使用并得到启发，可以替换查询语句中的表名。

二.编写测试代码

引入pom文件

com.foundationdb

fdb-sql-parser

1.3.0

复写NodeToString这个类

NodeToString这个类的作用就是将语法树转换为SQL语句，遍历到表节点是会调用fromBaseTable(FromBaseTable node)：String方法

public class MyNodeToString extends NodeToString{

@Override

protected String fromBaseTable(FromBaseTable node) throws StandardException {

String tn = "数据库类型." + toString(node.getOrigTableName());

String n = node.getCorrelationName();

if (n == null)

return tn;

else

return tn + " AS " + n;

}

}

进行调用

import com.foundationdb.sql.StandardException;

import com.foundationdb.sql.parser.SQLParser;

import com.foundationdb.sql.parser.StatementNode;

import java.util.ArrayList;

import java.util.List;

/**

* @Author chenxl

* @Date 2016/11/16 22:00

* @Describle

*/

public class Parser {

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

String sql1 = "Select * from zpc1";

String sql2 = "Select name,ip from zpc2 bieming where age > 10 and area in (select area from city)";

String sql3 = "Select d.name,d.ip from (select * from zpc3 where age > 10 and area in (select area from city)) d";

String sql4 = "create table zpc(id string, name string)";

// String sql5 = "insert overwrite table tmp1 PARTITION (partitionkey='2008-08-15') select * from tmp";

// String sql6 = "FROM ( SELECT p.datekey datekey, p.userid userid, c.clienttype FROM detail.usersequence_client c JOIN fact.orderpayment p ON p.orderid = c.orderid "

// + " JOIN default.user du ON du.userid = p.userid WHERE p.datekey = 20131118 ) base INSERT OVERWRITE TABLE `test`.`customer_kpi` SELECT base.datekey, "

// + " base.clienttype, count(distinct base.userid) buyer_count GROUP BY base.datekey, base.clienttype";

// String sql7 = "SELECT id, value FROM (SELECT id, value FROM p1 UNION ALL SELECT 4 AS id, 5 AS value FROM p1 limit 1) u";

String sql8 = "select dd from(select id+1 dd from zpc) d";

String sql9 = "select dd+1 from(select id+1 dd from zpc) d";

// String sql10 = "truncate table zpc";

// String sql11 = "drop table zpc";

String sql12 = "select * from tablename where unix_timestamp(cz_time) > unix_timestamp('2050-12-31 15:32:28')";

String sql15 = "alter table old_table_name RENAME TO new_table_name";

String sql16 = "select statis_date,time_interval,gds_cd,gds_nm,sale_cnt,discount_amt,discount_rate,price,etl_time,pay_amt from o2ostore.tdm_gds_monitor_rt where time_interval = from_unixtime(unix_timestamp(concat(regexp_replace(from_unixtime(unix_timestamp('201506181700', 'yyyyMMddHHmm')+ 84600 , 'yyyy-MM-dd HH:mm'),'-| |:',''),'00'),'yyyyMMddHHmmss'),'yyyy-MM-dd HH:mm:ss')";

// String sql13 = "INSERT OVERWRITE TABLE u_data_new SELECT TRANSFORM (userid, movieid, rating, unixtime) USING 'python weekday_mapper.py' AS (userid, movieid, rating, weekday) FROM u_data";

String sql14 = "SELECT a.* FROM a JOIN b ON (a.id = b.id AND a.department = b.department)";

// String sql17 = "LOAD DATA LOCAL INPATH \"/opt/data/1.txt\" OVERWRITE INTO TABLE table1";

// String sql18 = "CREATE TABLE table1 ( column1 STRING COMMENT 'comment1', column2 INT COMMENT 'comment2' )";

// String sql19 = "ALTER TABLE events RENAME TO 3koobecaf";

// String sql20 = "ALTER TABLE invites ADD COLUMNS (new_col2 INT COMMENT 'a comment')";

// String sql21 = "alter table mp add partition (b='1', c='1')";

// String sql22 = "select login.uid from login day_login left outer join (select uid from regusers where dt='20130101') day_regusers on day_login.uid=day_regusers.uid where day_login.dt='20130101' and day_regusers.uid is null";

String sql23 = "select name from (select * from zpc left outer join def on zpc.id=def.id) d";

List list = new ArrayList();

list.add(sql1);

list.add(sql2);

list.add(sql3);

// list.add(sql4);

// list.add(sql5);

// list.add(sql6);

// list.add(sql7);

list.add(sql8);

list.add(sql9);

// list.add(sql10);

// list.add(sql11);

list.add(sql12);

// list.add(sql13);

list.add(sql14);

list.add(sql15);

list.add(sql16);

// list.add(sql17);

// list.add(sql18);

// list.add(sql19);

// list.add(sql20);

// list.add(sql21);

// list.add(sql22);

list.add(sql23);

SQLParser parser = new SQLParser();

// StatementNode stmt = parser.parseStatement(

// "select userid,username,password " +

// "from sys_user,sys_money where username = 'isea533'");

// stmt.treePrint();

MyNodeToString unparser = new MyNodeToString();

String sql = "";

for (String s : list) {

StatementNode stmt = parser.parseStatement(s);

sql = unparser.toString(stmt);

System.out.println(sql);

}

}

}

测试结果

E:\soft\Java\jdk1.8.0_101\bin\java -Didea.launcher.port=7532 "-Didea.launcher.bin.path=E:\soft\IntelliJ IDEA 2016.2.4\bin" -Dfile.encoding=UTF-8 -classpath "E:\soft\Java\jdk1.8.0_101\jre\lib\charsets.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\deploy.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\access-bridge-64.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\cldrdata.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\dnsns.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\jaccess.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\jfxrt.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\localedata.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\nashorn.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\sunec.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\sunjce_provider.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\sunmscapi.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\sunpkcs11.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\ext\zipfs.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\javaws.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\jce.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\jfr.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\jfxswt.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\jsse.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\management-agent.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\plugin.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\resources.jar;E:\soft\Java\jdk1.8.0_101\jre\lib\rt.jar;E:\IDEAProject\SQLParseTest\target\test-classes;E:\IDEAProject\SQLParseTest\target\classes;C:\Users\chenxl\.m2\repository\com\foundationdb\fdb-sql-parser\1.3.0\fdb-sql-parser-1.3.0.jar;E:\soft\IntelliJ IDEA 2016.2.4\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain Parser

SELECT * FROM 数据库类型.zpc1

SELECT name, ip FROM 数据库类型.zpc2 AS bieming WHERE (age > 10) AND (area IN (SELECT area FROM 数据库类型.city))

SELECT d.name AS name, d.ip AS ip FROM (SELECT * FROM 数据库类型.zpc3 WHERE (age > 10) AND (area IN (SELECT area FROM 数据库类型.city))) AS d

SELECT dd FROM (SELECT (id + 1) AS dd FROM 数据库类型.zpc) AS d

SELECT (dd + 1) FROM (SELECT (id + 1) AS dd FROM 数据库类型.zpc) AS d

SELECT * FROM 数据库类型.tablename WHERE unix_timestamp(cz_time) > (unix_timestamp(('2050-12-31 15:32:28')))

SELECT a.* FROM 数据库类型.a INNER JOIN 数据库类型.b ON ((a.id = b.id) AND (a.department = b.department))

**UNKNOWN(114)**

SELECT statis_date, time_interval, gds_cd, gds_nm, sale_cnt, discount_amt, discount_rate, price, etl_time, pay_amt FROM 数据库类型.o2ostore.tdm_gds_monitor_rt WHERE time_interval = (from_unixtime((unix_timestamp((concat((regexp_replace((from_unixtime(((unix_timestamp('201506181700', 'yyyyMMddHHmm')) + 84600), ('yyyy-MM-dd HH:mm'))), ('-| |:'), '')), '00')), 'yyyyMMddHHmmss')), ('yyyy-MM-dd HH:mm:ss')))

SELECT name FROM (SELECT * FROM 数据库类型.zpc LEFT OUTER JOIN 数据库类型.def ON (zpc.id = def.id)) AS d

Process finished with exit code 0

上述代码测试了有些查询操作，至于修改和插入还未测试，我们的需求主要是查询。