mysql5

问题 Is there a more-efficent, less laborious way of copying all records from one table to another that doing this: INSERT INTO product_backup SELECT * FROM product Typically, the product table will hold around 50,000 records. Both tables are identical in structure and have 31 columns in them. I'd like to point out this is not my database design, I have inherited a legacy system. 回答1: There's just one thing you're missing. Especially, if you're using InnoDB, is you want to explicitly add an ORDER

问题 Is there a more-efficent, less laborious way of copying all records from one table to another that doing this: INSERT INTO product_backup SELECT * FROM product Typically, the product table will hold around 50,000 records. Both tables are identical in structure and have 31 columns in them. I'd like to point out this is not my database design, I have inherited a legacy system. 回答1: There's just one thing you're missing. Especially, if you're using InnoDB, is you want to explicitly add an ORDER

问题 I have one database in mysql. But when i log into phpMyAdmin , it shows another database called information_schema. Is that database always present with one database? I mean to say is there a copy of information_schema for every database present in mysql or is there one database called inforemation_schema per mysql server? If i modify this information_schema database how will that affect my current database? 回答1: You can think of information_schema as a "master database" that holds details

问题 I'm using Blender 2.74 and Python 3.4 with the correct connector for MySQL. (By the way, I'm just a beginner in using Blender and Python.) What I want is to make a login UI and save the inputted name into the database, but my code seems a bit off or wrong. When I try to run the code, it didn't save the value in the variable, but when i try to run it in python IDE (PyCharm) it worked. Here's the code: import sys sys.path.append('C:\Python34\Lib\site-packages') sys.path.append('C:\Python34\DLLs

问题 So what happens when you use a negative value in a LIMIT clause? Will there be negative consequences (slight pun intended)? I don't see any documentation on this, and MySQL forums, as I recall, sux. Background: I'm using MySQL CE 5.5.20. I wrote a stored procedure that take an int parameter and uses it for the LIMIT clause. I needed a way to return all rows if I wanted, so I tried passing in -1 for the limit parameter in my store procedure/routine, and that worked. 回答1: According to the

问题 I have a 8 sets of data of about 30,000 rows for each set, the data is the same structure just for different languages. The front end of the site will get relatively high traffic. So my question is regarding MySQL performance, if i should have a single table with one column to distinguish which set the data belongs to (i.e. coloumn "language") or create individual tables for each language set? (an explanation on why if possible would be really helpful) Thanks in advance Shadi 回答1: I would go

问题 I have created a PHP / MySQL based web service. I wrote client.php as mentioned here and server.php as below: <?php require_once("lib/nusoap.php"); $host = $_SERVER['HTTP_HOST']; $miURL = 'http://'.$host.'/WS-Demo'; $server = new nusoap_server(); $server->configureWSDL('L3M_WebService', $miURL); $server->wsdl->schemaTargetNamespace=$miURL; $server->register('getDemoData', array('fldpara' => 'xsd:Array', 'tblpara' => 'xsd:Array', 'cndpara' => 'xsd:Array'), array('return' => 'xsd:string'),

问题 I am using MySQL 5.0+ and I am trying to execute a big list of commands if a table does not exist. So I would like to have: if not exist table then 10000 line query that creates and populates the table with a lot of entries. end if The only problem is that I have been searching and so far I found out that MySQL does not support such a feature. At the current moment I have: IF NOT EXISTS `profiles` THEN A LOT OF QUERIES; END IF; For some reason it keeps on giving me error saying syntax is

问题 I have a sample table (table_name: track_task) like below: task_id stage log_date ---------------------------------------- 3 1 2011-06-01 08:36:21 9 1 2011-06-03 12:35:47 3 2 2011-06-05 14:25:42 21 1 2011-06-11 13:03:34 9 2 2011-06-11 15:25:57 3 3 2011-06-12 10:16:09 21 2 2011-06-15 15:30:29 3 4 2011-06-22 15:34:33 21 3 2011-06-23 12:53:49 9 4 2011-06-25 16:25:08 The data above is automatically populated when a task stage is progressed by some action in the application code. The stages run

问题 Hi I want to know which kind of queries are good with multiple tables. For eg: select table1.id, table1.name from table1,table2,table3 where table1.id=table2.id and table2.id=table3.id or select table1.id, table1.name from table1 inner join table2 on table1.id=table2.id inner join table3 on table2.id=table3.id where 1 or select table1.id, table1.name from table1 join table2 on table1.id=table2.id join table3 on table2.id=table3.id where 1 Which kind of query is best for performance? 回答1: They