Question

Need to load data from a single file with a 100,000+ records into multiple tables on MySQL maintaining the relationships defined in the file/tables; meaning the relationships already match. The solution should work on the latest version of MySQL, and needs to use the InnoDB engine; MyISAM does not support foreign keys.

I am a completely new to using Perl and any pointers would be appreciated.

I might add that it is a requirement that the foreign key constraints are NOT disabled during the loading of the data. Since it’s my understanding that if there is something wrong with the database’s referential integrity, MySQL will not check for referential integrity when the foreign key constraints are turned back on. SOURCE: 5.1.4. Server System Variables — foreign_key_checks

Any approach should include some from of validation and a rollback strategy should an insert fail, or fail to maintain referential integrity.

Again, completely new to this, and doing my best to provide as much information as possible, if you have any questions, or request for clarification — just let me know.

If Perl is not well suited for this, please explain why, and if possible suggest another approach. Perl was selected as an option because the client’s team has deployed 40-65 Perl scripts already, and has many people on staff that are able to read/edit it.

Thanks!

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SAMPLE DATA: To better elaborate with an example, lets assume I am trying to load a file containing employee name, the offices they have occupied in the past and their Job title history separated by a tab.

File:

EmployeeName<tab>OfficeHistory<tab>JobLevelHistory
John Smith<tab>501<tab>Engineer
John Smith<tab>601<tab>Senior Engineer
John Smith<tab>701<tab>Manager
Alex Button<tab>601<tab>Senior Assistant
Alex Button<tab>454<tab>Manager

NOTE: The single table database is completely normalized (as much as a single table may be) — and for example, in the case of “John Smith” there is only one John Smith; meaning there are no duplicates that would lead to conflicts in referential integrity.

The MyOffice database schema has the following tables:

Employee (nId, name)
Office (nId, number)
JobTitle (nId, titleName)
Employee2Office (nEmpID, nOfficeId)
Employee2JobTitle (nEmpId, nJobTitleID)

So in this case. the tables should look like:

Employee
1 John Smith
2 Alex Button

Office
1 501
2 601
3 701
4 454

JobTitle
1 Engineer
2 Senior Engineer
3 Manager
4 Senior Assistant

Employee2Office
1 1
1 2
1 3
2 2
2 4

Employee2JobTitle
1 1
1 2
1 3
2 4
2 3

Here’s the MySQL DDL to create the database and tables:

create database MyOffice2;

use MyOffice2;

CREATE TABLE Employee (
      id MEDIUMINT NOT NULL AUTO_INCREMENT,
      name CHAR(50) NOT NULL,
      PRIMARY KEY (id)
    ) ENGINE=InnoDB;

CREATE TABLE Office (
  id MEDIUMINT NOT NULL AUTO_INCREMENT,
  office_number INT NOT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB;

CREATE TABLE JobTitle (
  id MEDIUMINT NOT NULL AUTO_INCREMENT,
  title CHAR(30) NOT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB;

CREATE TABLE Employee2JobTitle (
  employee_id MEDIUMINT NOT NULL,
  job_title_id MEDIUMINT NOT NULL,
  FOREIGN KEY (employee_id) REFERENCES Employee(id),
  FOREIGN KEY (job_title_id) REFERENCES JobTitle(id),
  PRIMARY KEY (employee_id, job_title_id)
) ENGINE=InnoDB;

CREATE TABLE Employee2Office (
  employee_id MEDIUMINT NOT NULL,
  office_id MEDIUMINT NOT NULL,
  FOREIGN KEY (employee_id) REFERENCES Employee(id),
  FOREIGN KEY (office_id) REFERENCES Office(id),
  PRIMARY KEY (employee_id, office_id)
) ENGINE=InnoDB;

Answer 1

This sounds like a job for DBIx::Class.