I installed xampp,but when I tried to run it I got an error as thus: Error MySQL said: Documentation 1045 – Access denied for user ‘root’@’localhost’ (using password: NO) Connection for controluser as defined in your configuration failed. phpMyAdmin tried to connect to the MySQL server, and the server rejected the connection. You should check … Read more
For those arriving at this question because of the question title (as I did), this solved my problem: This error can indicate that the table’s PRIMARY KEY is not set to AUTO-INCREMENT, (and your insert query did not specify an ID value). To resolve: Check that there is a PRIMARY KEY set on your table, and that the … Read more
8 I use Mysql Workbench to connect my database,[ Hostname Port and Username are as shown in figure ,and password is right.When I click Test Connection ,it show as above.But if i use 3307 in place of 3306 as port,it connect sucessfully. What matter lead that and how I fix it? I use macbook pro … Read more
When dealing with null, = does not match the null values. You can use IS NULL or IS NOT NULL LIMIT can be used with UPDATE but with the row count only
I have a query where I am using GROUP_CONCAT and a custom separator as my results may contain commas: ‘—-‘ This all works well, however it is still comma separated, so my output is: How can I make it so the output is: I thought this was the idea of a custom separator! Failing that, … Read more
MERGE is not supported by MySQL, However, there is other possible way of doing the same: INSERT…ON DUPLICATE KEY UPDATE If you specify the ON DUPLICATE KEY UPDATE option in the INSERT statement and the new row causes a duplicate value in the UNIQUE or PRIMARY KEY index, MySQL performs an update to the old row … Read more
I found the solution to my problem myself, but I still don’t quite understand why it didn’t work: I granted privileges to that user on the hosts % and localhost: With these settings I got the results I showed above. When I granted privileges to that user on host it suddenly did work. Apparently % … Read more
I don’t believe MySQL supports dynamic sql. You can do “prepared” statements which is similar, but different. Here is an example: The prepared statements are often used to see an execution plan for a given query. Since they are executed with the execute command and the sql can be assigned to a variable you can approximate the some of … Read more
I would use a composite (multi-column) key. This way you can have t1ID and t2ID as foreign keys pointing to their respective tables as well.
767 bytes in MySQL version 5.6 (and prior versions), is the stated prefix limitation for InnoDB tables. It’s 1,000 bytes long for MyISAM tables. This limit has been increased to 3072 bytes In MySQL version 5.7 (and upwards). You also have to be aware that if you set an index on a big char or varchar field which is utf8mb4 encoded, you have to … Read more