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Oracle find a constraint
...stem generated constraint name. For instance, if we specify NOT NULL in a table declaration. Or indeed a primary or unique key. For example:
SQL> create table t23 (id number not null primary key)
2 /
Table created.
SQL> select constraint_name, constraint_type
2 from user_constraint...
MySQL 启动报错 Table \'mysql.plugin\' doesn\'t exist - 数据库(内核) -...
MySQL 启动报错 Table 'mysql.plugin' doesn't exist 启动报错： opt szy bin mysqld: Table 'mysql.plugin ' doesn 't exist141211 15:06:12 [ERROR] Can 't open t...启动报错：
/opt/szy/bin/mysqld: Table \'mysql.plugin\' doesn\'t exist
141211 15:06:12 [ERROR] Can\'t open the mysql.plug...
What is Normalisation (or Normalization)?
...he other, which is data corruption. The problem is solved by splitting the table in two, and creating a primary key/foreign key relationship:
UserId(FK) | Car UserId(PK) | UserName
--------------------- -----------------
1 | Toyota 1 | John
2 ...
Is a DIV inside a TD a bad idea?
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Using a div instide a td is not worse than any other way of using tables for layout. (Some people never use tables for layout though, and I happen to be one of them.)
If you use a div in a td you will however get in a situation where it might be hard to predict how the elements will be siz...
MySQL “incorrect string value” error when save unicode string in Django
...developer here)
To solve this you need to:
Change your MySQL database, table and columns to use the utf8mb4 character set (only available from MySQL 5.5 onwards)
Specify the charset in your Django settings file as below:
settings.py
DATABASES = {
'default': {
'ENGINE':'django.db....
常用Sql - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
常用Sqlmysql：drop table if exists tablename;不能写成drop table tablename if exists tablename;mysql：建立索引SqlCREATE TABLE t...mysql：drop table if exists tablename;
不能写成
drop table tablename if exists tablename;
mysql：建立索引Sql
CREATE TABLE tablename (
`ID...
What good are SQL Server schemas?
...
Schemas logically group tables, procedures, views together. All employee-related objects in the employee schema, etc.
You can also give permissions to just one schema, so that users can only see the schema they have access to and nothing else.
...
2 column div layout: right column with fixed width, left fluid
...
Simplest and most flexible solution so far it to use table display:
HTML, left div comes first, right div comes second ... we read and write left to right, so it won't make any sense to place the divs right to left
<div class="container">
<div class="left">
...
What is the difference between “word-break: break-all” versus “word-wrap: break-word” in CSS
...at the container width — especially if the container is a pre element or table cell where the word-wrap property may not work as expected.
– gfullam
Jun 2 '15 at 18:50
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Select all columns except one in MySQL?
...g to use a select statement to get all of the columns from a certain MySQL table except one. Is there a simple way to do this?
...