order by column

BasicCommands for the database:View all databases: show databases;View the currently used databases: Select database ();Switch database: use database name;Creating database: Create database name Charset=utf8;Delete the database: drop database

First, the fieldEach row in a database table is called a "record", and each record contains all the information in the row, but the record does not have a specific record name in the database, and it is often indicated by the number of rows it is in.

Here, let's move on to the question left in section 2.6: What if the string to be queried contains "_" or "%"? Start today's study.2.7 How to use escaped (escape) operatorsThis task can be accomplished with an escape keyword. In order to practice,

SQL (Structure query Language, Structured Query language) was proposed by Boyce and Chamberlin in 1975 to implement query, selection and other operations in relational operations. As a standard language for relational database operations, it has

SQL CRUD additions and deletions to review summary1. Create a databaseCREATE database nameDeleting a databaseDROP database name2. Create a tableCREATE TABLE table name(column name Type (length) from the growth primary key is not empty,)Self-growth:

Reprint: http://www.cnblogs.com/yangxia-test/archive/2012/09/20/2695617.htmlImplementing select Top N in Oracle:Because Oracle does not support the SELECT top statement, it is often used in Oracle with order by and RowNumTo implement the query for

InnoDB row format in two formats (compact,redundant) The storage format of the compact Compact is a non-null, variable-length list of field lengths, and is placed in reverse order by column, when the length of the column is less than 255 bytes,

1. What is SQL injectionSQL injection, by inserting a SQL command into a form form to submit or entering a query string for a domain name or page request, eventually achieves a malicious SQL command by tricking the server into executing. Construct

One, group function nestingAs defined in Oracle, group functions can be nested only two layers. In fact, multi-layer nesting has no practical purpose, so Oracle does not provide multi-layered nesting of group functions. However, a single-line

 create database schooldata Go use schooldata go create table Student ( sno char (3) primary key,  sname CH AR (8) NOT NULL,  ssex char (2) is not NULL,  sbirthday date,  class char (5)) Go CREATE table Teacher (  Tno char (3) primary key,  tname

1.oracle Database Paging1 Select * from (Select A.*fromwhere rownumwhere a.rc>= StartRow2.DB2 Database Paging1 Select * from (Select over as rc,a.)* from (select*from orderby aswherebetween and Endrow3.SQL Server 2000 Database Paging1 Select Top *

SQL2008 expression: Is any combination of constants, variables, columns, or functions, and operators.1. String functionsFunction Name Parameter Example descriptionASCII (string expression)Select ASCII (' ABC ') returns 97Returns the ASCII code of

First, landingSQL Server two logon mode settings: Windows identity logon, SQL Server identity logon.How do I set up SQL Server authentication?1. Object Explorer Right-click-Properties--Security--sqlserver and Windows identity login.2. Object

Oracle does not support top NSELECT * FROM (SELECT * to T_weixin_homework ORDER by SUBSTR (hometitle,0,10) desc) where rownumOur main discussion today is the actual operation of Oracle's implementation of SELECT TOP N, the following is an

First, T-SQL base statement1. Creating database: Create DATABASEname (not Chinese, cannot start with a number, cannot start with a symbol)2. Delete the database:drop databases database name3. Select database: Use database name4. Creating tables:

Syntax: Row_number () Over (PARTITION by column ORDER by column)In a nutshell, Row_number () returns a number for each grouped record starting at 1, where Row_number () over (order by XLH DESC) returns an ordinal of the XLH column in descending

Creation of database tablesCREATE table ( [NOT NULL], ... )Delete a tableDROP table Import and Export dataTurn the table into SQL codeBackup and restoreincrease, delete, change, check CRUDAdd to:INSERT into [(column 1, column 2 ...)] VALUES (,['

Creating database: Create library name;Creating Table: Create table table name (column name data type (length) primary key, column name data type is empty ... ）；Note: Do not add commas to the last column. Multiple statements are executed together,

increase, delete, change, checkCRUD: Create retrive Update DeleteInsert into table name >(column 1, column 2 ... ) Values (' value 1', ' Value 2') numbers without quotesAttention:1. match the column to the value. (Quantity, type, order)2. The

Tidy up the things on this machine, are the previous study time shun notes of the essay, hoping to give the program Department of children a little help.SQL syntax is generally common in SQL databases, and the simplest of these is the most common