我想知道如何创建默认值。
例如：
CREATE TABLE something
(
name varchar(20),
rank int
)
我想将RANK值设置为1。
（每当我添加新记录时，rank都会自动设置为1）。
CREATE TABLE something
(
name varchar(20),
rank int default 1
)
如果表已经存在，并且您想添加默认值，最快的方法是使用ALTER table，如下所示：
ALTER TABLE something
ALTER COLUMN rank SET DEFAULT 1;
I noticed that there were some threads with similar questions, and I did look through them but did not really get a convincing answer. Here s my question: The subquery below returns a Table with 3 ...
<?php $con=mysql_connect("localhost","mts","mts"); if(!con) { die( unable to connect . mysql_error()); } mysql_select_db("mts",$con); /* date_default_timezone_set ("Asia/Calcutta"); $date = ...
我把我的用心从使用QQL转向MySQL。 它与凯科特合作,现在不工作,因为我已经改变,使用MySQL。 这里的错误信息是:
We have a restaurant table that has lat-long data for each row. We need to write a query that performs a search to find all restaurants within the provided radius e.g. 1 mile, 5 miles etc. We have ...
Is it possible in php to return a specific row of data from a mysql query? None of the fetch statements that I ve found return a 2 dimensional array to access specific rows. I want to be able to ...
Our website was developed with a meta tag set to... <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> This works fine for M-dashes and special quotes, etc. However, I ...
What are some of the strategies being used for pagination of data sets that involve complex queries? count(*) takes ~1.5 sec so we don t want to hit the DB for every page view. Currently there are ~...
My table looks like person_id | car_id | miles ------------------------------ 1 | 1 | 100 1 | 2 | 200 2 | 3 | 1000 2 | 4 | 500 I need to ...