大约有 7,000 项符合查询结果（耗时：0.0149秒） [XML]
Unique constraint that allows empty values in MySQL
...
Yes, you can do this. See the MySQL reference (version 5.5).
A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. For all eng...
How to move columns in a MySQL table?
Currently I am having the following MySQL table: Employees (empID, empName, department);
4 Answers
...
Why is it bad style to `rescue Exception => e` in Ruby?
... You can also ADAPTER_ERRORS = [::ActiveRecord::StatementInvalid, PGError, Mysql::Error, Mysql2::Error, ::ActiveRecord::JDBCError, SQLite3::Exception] and then rescue *ADAPTER_ERRORS => e
– j_mcnally
Feb 27 '14 at 2:19
...
SQL: deleting tables with prefix
...
You cannot do it with just a single MySQL command, however you can use MySQL to construct the statement for you:
In the MySQL shell or through PHPMyAdmin, use the following query
SELECT CONCAT( 'DROP TABLE ', GROUP_CONCAT(table_name) , ';' )
AS statement...
Duplicating a MySQL table, indices, and data
How do I copy or clone or duplicate the data, structure,
and indices of a MySQL table to a new one?
10 Answers
...
MySQL/SQL: Group by date only on a Datetime column
...son. I would expect it to fail anywhere else as well. Can you confirm that MySQL actually handles this query?
– Tomalak
Dec 14 '08 at 15:56
1
...
MySQL convert date string to Unix timestamp
...
You will certainly have to use both STR_TO_DATE to convert your date to a MySQL standard date format, and UNIX_TIMESTAMP to get the timestamp from it.
Given the format of your date, something like
UNIX_TIMESTAMP(STR_TO_DATE(Sales.SalesDate, '%M %e %Y %h:%i%p'))
Will gives you a valid timestam...
Equals(=) vs. LIKE
... operators produce obviously different results. Allow me to quote from the MySQL manual:
Per the SQL standard, LIKE performs matching on a per-character basis, thus it can produce results different from the = comparison operator:
mysql> SELECT 'ä' LIKE 'ae' COLLATE latin1_german2_ci;
+----...
How to convert timestamp to datetime in MySQL?
How to convert 1300464000 to 2011-03-18 16:00:00 in MySQL?
5 Answers
5
...
Illegal mix of collations MySQL Error
...E your_table_name CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
MySQL sneaks swedish in there sometimes for no sensible reason.
share
|
improve this answer
|
follo...