I’m using Redmine to manage projects and bug reports, I was needing a daily report with spent time by user on each project, nothing complicated, but I wanted a cross-reference result like Excel dynamic tables. As we know, MySQL doesn’t support dynamic cross-reference queries but I make an approach:
1. Write the main query with rows: project identifier, task subject and …
I discovered a feature (or bug) of MySQL timestamp fields. Maybe is documented in some place what I not read yet:
When I add a new timestamp field to a table, MySQL magically adds some features to new timestamp field like a “trigger” and a default value to CURRENT_TIMESTAMP.
There is test-case script:
1052435203674f41c28ec94_000006
What happened? I dont know.
The new table structure is:
1052435203674f41c28ec94_000007
It only …
I was tired to get manually disk space used for all MySQL databases, I just created a stored procedure to get an overview of the database sizes in our MySQL server.
MySQL don’t have a command that allows us an overall summary of the databases, something like SHOW TABLE STATUS for databases. The “SHOW DATABASES” command lists only the current databases …
I have used tools like MySQL Migration Toolkit (*) and Bullzip’s Access To MySQL utility, both do a excellent job but without relationships. We can spend a lot of hours to identifying and creating relationships until now:
I have write a VBA script to identify MS-Access relationships and create MySQL code with SQL-CREATE sentences, it will be useful after …
I just finished a database modification, a new foreign key creation shouldn’t be take more than 5 mins, but I spent 2 hours because MySQL still have some useless error messages.
There is a way to create a new foreign key:
1052435203674f41c28ec94_000011
The last sentence returns a generic error message:
Error Code: 1005. Can’t create table ‘temp.#sql-4bd7_11’ (errno: 150)
Everything would have been easier if …
Do you get write laziness in the command line everything what you need to connect to a MySQL server every time?
It may take less than minute, but sometimes one minute is vital (especially if we’re near the end of the world):
1052435203674f41c28ec94_000012
When we are hurry, these commands often fail several times per minute.
The solution: we can create shortcuts with bash alias …
The auto_increment for MySQL fields are very useful but what about if I need a custom auto-increment like a custom format like 001-000033,
001-000034
001-000035
001-000036
…
To make it possible we have an option based on past article MySQL Sequences:
From command line we have the entire MySQL server on hands (if we have privileges too of course) but we don’t have a overall overview, at this point the show table status command is every useful, or not?.
This is what we get when run show table status in a standard 80×25 terminal screen:
…
Those who have used PostgresSQL usually gets lazy when write the SQL code to auto-numeric fields, but we miss that feature when we are in a MySQL database.
As we know, MySQL have auto-increment fields, that are very useful too, but we miss that feature when we are in a PostgreSQL …
