Apache Presto Tutorial - MySQL Connector

MySQL connector for an external MySQL database queries.

Prerequisites

MySQL server installation.

Configuration settings

I hope you have the mysql server is installed on your computer. To enable property on Presto mysql server, you must  "etc / catalog"  Create a directory  "mysql.properties " file. Issue the following command to create a mysql.properties file.

$ cd etc 
$ cd catalog 
$ vi mysql.properties   

connector.name = mysql 
connection-url = jdbc:mysql://localhost:3306 
connection-user = root 
connection-password = pwd 

Save the file and exit the terminal. In the file, you must enter your password in mysql connection-password field.

Create a database in the MySQL server

Open the MySQL server and create a database using the following command.

create database tutorials

You have now created a "tutorials" in the server database. To enable the database type, use the command "use tutorials" in the query window.

Create a table

Let's create a simple table on "tutorials" database.

create table author(auth_id int not null, auth_name varchar(50),topic varchar(100))

Insert Table

After you create a table, use the following query insert three records.

insert into author values(1,'Doug Cutting','Hadoop') 
insert into author values(2,’James Gosling','java') 
insert into author values(3,'Dennis Ritchie’,'C')

Select the Record

To retrieve all the records, enter the following query.

Inquire

select * from author

result

auth_id    auth_name      topic  
1        Doug Cutting     Hadoop 
2        James Gosling    java 
3        Dennis Ritchie     C 

So far, you've been using MySQL server query data. Let's connect the memory card to the Presto Mysql server.

Presto CLI connection

Enter the following command to connect MySql plug-in on Presto CLI.

./presto --server localhost:8080 --catalog mysql --schema tutorials 

You will receive the following response.

presto:tutorials> 

Where  "tutorials"  refers to the mysql server schema.

Lists the schema

To list all the schema mysql, enter the following query in the Presto server.

Inquire

presto:tutorials> show schemas from mysql;

result

      Schema 
 
 information_schema 
 performance_schema 
 sys 
 tutorials

From the results, we can conclude that the first three are predefined schema, a schema is the last you create yourself.

Listed in the table from Schema

The following query will list "tutorials" all the tables in the schema.

Inquire

presto:tutorials> show tables from mysql.tutorials; 

result

  Table 
 
 author

In this schema we only created one table. If you create more than one table, it will list all the tables.

Description Table

To description field, enter the following query.

Inquire

presto:tutorials> describe mysql.tutorials.author;

result

  Column   |     Type     | Comment 
---+--+- 
 auth_id   | integer      | 
 auth_name | varchar(50)  | 
 topic     | varchar(100) |

Table Column Display

Inquire

presto:tutorials> show columns from mysql.tutorials.author; 

result

 Column    |     Type     | Comment 
---+--+- 
 auth_id   | integer      | 
 auth_name | varchar(50)  | 
 topic     | varchar(100) |

Access table records

Mysql table from the get all the records, issue the following query.

Inquire

presto:tutorials> select * from mysql.tutorials.author; 

result

auth_id  |   auth_name    | topic 
-++ 
       1 | Doug Cutting   | Hadoop 
       2 | James Gosling  | java 
       3 | Dennis Ritchie | C

From this result, you can retrieve mysql server records in the Presto.

Create a table using as a command

Mysql connector does not support creating table query, but you can create a table using as a command.

Inquire

presto:tutorials> create table mysql.tutorials.sample as 
select * from mysql.tutorials.author; 

result

CREATE TABLE: 3 rows

You can not insert rows directly, because this connector has some limitations. It does not support the following query -

• create
• insert
• Update
• delete
• drop

To view the newly created records in the table, enter the following query.

Inquire

presto:tutorials> select * from mysql.tutorials.sample; 

result

auth_id  |   auth_name    | topic 
-++ 
       1 | Doug Cutting   | Hadoop 
       2 | James Gosling  | java 
       3 | Dennis Ritchie | C

Original link large column  https://www.dazhuanlan.com/2019/07/19/apache-presto%e6%95%99%e7%a8%8b-mysql%e8%bf%9e%e6%8e%a5% e5% 99% a8 /