Technically yes, but if a string makes sense to be the primary key then you should probably use it. This all depends on the size of the table you’re making it for and the length of the string that is going to be the primary key (longer strings == harder to compare). I wouldn’t necessarily … Read more
For InnoDB, the following seems to work: create the new empty database, then rename each table in turn into the new database: RENAME TABLE old_db.table TO new_db.table; You will need to adjust the permissions after that. For scripting in a shell, you can use either of the following: mysql -u username -ppassword old_db -sNe ‘show … Read more
I think your last statement is the best way. You can also try SELECT A.* from A left join B on A.x = B.y where B.y is null
You should use “ORDER BY FIELD“. So, for instance: SELECT * FROM table WHERE id IN (118,17,113,23,72) ORDER BY FIELD(id,118,17,113,23,72)
The moral of this story is: Don’t use a different software stack for development and production. Never. You’ll just end up with bugs which you can’t reproduce in dev; your testing will be worthless. Just don’t do it. Using a different database engine is out of the question – there will be FAR more cases … Read more
|| represents string concatenation. Unfortunately, string concatenation is not completely portable across all sql dialects: ansi sql: || (infix operator) mysql: concat ( vararg function ). caution: || means ‘logical or’ (It’s configurable, however; thanks to @hvd for pointing that out) oracle: || (infix operator), concat ( caution: function of arity 2 only ! ) … Read more
Just running the SELECT statement will have no effect on the data. You have to use an UPDATE statement with the REPLACE to make the change occur: UPDATE photos SET caption = REPLACE(caption,'”‘,’\”) Here is a working sample: http://sqlize.com/7FjtEyeLAh
For Upload large size data in using phpmyadmin Do following steps. Open php.ini file from C:\wamp\bin\apache\Apache2.4.4\bin Update following lines max_execution_time = 259200 max_input_time = 259200 memory_limit = 1000M upload_max_filesize = 750M post_max_size = 750M than after restart wamp server or restart all services Now Upload data using import function in phymyadmin. Apply second step if … Read more
From the answer I got here: You can use: SET [GLOBAL|SESSION] sql_mode=”NO_AUTO_VALUE_ON_ZERO” Which as described here, will prevent MySQL from interpreting an INSERT/UPDATE ID of 0 as being the next sequence ID. Such behaviour will be limited to NULL. It is what I’d consider pretty bad behaviour from the application though. You’ll have to be … Read more
->STRICT_TRANS_TABLES is responsible for setting MySQL strict mode. ->To check whether strict mode is enabled or not run the below sql: SHOW VARIABLES LIKE ‘sql_mode’; If one of the value is STRICT_TRANS_TABLES, then strict mode is enabled, else not. In my case it gave +————–+——————————————+ |Variable_name |Value | +————–+——————————————+ |sql_mode |STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION| +————–+——————————————+ Hence strict mode … Read more