大约有 40,000 项符合查询结果（耗时：0.0457秒） [XML]
How to create id with AUTO_INCREMENT on Oracle?
...acle 11g. However, you can model it easily with a sequence and a trigger:
Table definition:
CREATE TABLE departments (
ID NUMBER(10) NOT NULL,
DESCRIPTION VARCHAR2(50) NOT NULL);
ALTER TABLE departments ADD (
CONSTRAINT dept_pk PRIMARY KEY (ID));
CREATE SEQUENCE dept_seq STA...
What is the optimal length for user password salt? [closed]
...ices for how long the salt should be? I'll be storing the salt in my user table, so I would like the best tradeoff between storage size and security. Is a random 10 character salt enough? Or do I need something longer?
...
Return number of rows affected by UPDATE statements
...
CREATE PROCEDURE UpdateTables
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE @RowCount1 INTEGER
DECLARE @RowCount2 INTEGER
DECLARE @RowCount3...
Import SQL file into mysql
I have a database called nitm . I haven't created any tables there. But I have a SQL file which contains all the necessary data for the database. The file is nitm.sql which is in C:\ drive . This file has size of about 103 MB. I am using wamp server.
...
Why use multiple columns as primary keys (composite primary key)
...
Another example of compound primary keys are the usage of Association tables. Suppose you have a person table that contains a set of people and a group table that contains a set of groups. Now you want to create a many to many relationship on person and group. Meaning each person can belong t...
How to understand nil vs. empty vs. blank in Ruby
...
I made this useful table with all the cases:
blank?, present? are provided by Rails.
share
|
improve this answer
|
...
Any way to declare a size/partial border to a box?
...g...
Partly underlined text elements can easily achieved by using display:table or display:inline-block
(I just don't use display:inline-block because, yeah you know, the awkward 4px-gap).
Textual Elements
h1 {
border-bottom: 1px solid #f00;
display: table;
}
<h1>Foo is not equ...
Find rows that have the same value on a column in MySQL
In a [member] table, some rows have the same value for the email column.
8 Answers
8...
Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]
...it (for example: a foreign library, a file on disc, network data, CPU page tables, ...). In such a case the binary structure of data is also defined in a place inaccessible to the compiler, so reordering the struct fields would create a data type that is inconsistent with the other definitions. For ...
PostgreSQL - max number of parameters in “IN” clause?
... possible if the inputs are all scalars (no RowExprs) and there is a
* suitable array type available. If not, we fall back to a boolean
* condition tree with multiple copies of the lefthand expression.
* Also, any IN-list items that contain Vars are handled as separate
* boolean conditions, bec...