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SQL 教程

SQL 教程 SQL 简介 SQL 语法 SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min 和 Max SQL Count, Avg, Sum SQL Like SQL 通配符 SQL In SQL Between SQL 别名 SQL 联接 SQL Inner Join SQL Left Join SQL Right Join SQL Full Join SQL 自联接 SQL Union SQL Group By SQL Having SQL Exists SQL Any, All SQL Select Into SQL Insert Into Select SQL Case SQL Null 函数 SQL 存储过程 SQL 注释 SQL 运算符

SQL 数据库

SQL 创建数据库 SQL 删除数据库 SQL 数据库备份 SQL Create Table SQL Drop Table SQL Alter Table SQL 约束 SQL Not Null SQL Unique SQL Primary Key SQL Foreign Key SQL Check SQL Default SQL Index SQL 自动增量 SQL 日期 SQL 视图 SQL 注入 SQL 托管 SQL 数据类型

SQL 参考手册

SQL 关键字
ADD ADD CONSTRAINT ALTER ALTER COLUMN ALTER TABLE ALL AND ANY AS ASC BACKUP DATABASE BETWEEN CASE CHECK COLUMN CONSTRAINT CREATE CREATE DATABASE CREATE INDEX CREATE OR REPLACE VIEW CREATE TABLE CREATE PROCEDURE CREATE UNIQUE INDEX CREATE VIEW DATABASE DEFAULT DELETE DESC DISTINCT DROP DROP COLUMN DROP CONSTRAINT DROP DATABASE DROP DEFAULT DROP INDEX DROP TABLE DROP VIEW EXEC EXISTS FOREIGN KEY FROM FULL OUTER JOIN GROUP BY HAVING IN INDEX INNER JOIN INSERT INTO INSERT INTO SELECT IS NULL IS NOT NULL JOIN LEFT JOIN LIKE LIMIT NOT NOT NULL OR ORDER BY OUTER JOIN PRIMARY KEY PROCEDURE RIGHT JOIN ROWNUM SELECT SELECT DISTINCT SELECT INTO SELECT TOP SET TABLE TOP TRUNCATE TABLE UNION UNION ALL UNIQUE UPDATE VALUES VIEW WHERE
MySQL 函数
String 字符串函数 ASCII CHAR_LENGTH CHARACTER_LENGTH CONCAT CONCAT_WS FIELD FIND_IN_SET FORMAT INSERT INSTR LCASE LEFT LENGTH LOCATE LOWER LPAD LTRIM MID POSITION REPEAT REPLACE REVERSE RIGHT RPAD RTRIM SPACE STRCMP SUBSTR SUBSTRING SUBSTRING_INDEX TRIM UCASE UPPER Numeric 数值函数 ABS ACOS ASIN ATAN ATAN2 AVG CEIL CEILING COS COT COUNT DEGREES DIV EXP FLOOR GREATEST LEAST LN LOG LOG10 LOG2 MAX MIN MOD PI POW POWER RADIANS RAND ROUND SIGN SIN SQRT SUM TAN TRUNCATE Date 日期函数 ADDDATE ADDTIME CURDATE CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURTIME DATE DATEDIFF DATE_ADD DATE_FORMAT DATE_SUB DAY DAYNAME DAYOFMONTH DAYOFWEEK DAYOFYEAR EXTRACT FROM_DAYS HOUR LAST_DAY LOCALTIME LOCALTIMESTAMP MAKEDATE MAKETIME MICROSECOND MINUTE MONTH MONTHNAME NOW PERIOD_ADD PERIOD_DIFF QUARTER SECOND SEC_TO_TIME STR_TO_DATE SUBDATE SUBTIME SYSDATE TIME TIME_FORMAT TIME_TO_SEC TIMEDIFF TIMESTAMP TO_DAYS WEEK WEEKDAY WEEKOFYEAR YEAR YEARWEEK 高级功能 BIN BINARY CASE CAST COALESCE CONNECTION_ID CONV CONVERT CURRENT_USER DATABASE IF IFNULL ISNULL LAST_INSERT_ID NULLIF SESSION_USER SYSTEM_USER USER VERSION
SQL Server 函数
String 字符串函数 ASCII CHAR CHARINDEX CONCAT Concat with + CONCAT_WS DATALENGTH DIFFERENCE FORMAT LEFT LEN LOWER LTRIM NCHAR PATINDEX QUOTENAME REPLACE REPLICATE REVERSE RIGHT RTRIM SOUNDEX SPACE STR STUFF SUBSTRING TRANSLATE TRIM UNICODE UPPER Numeric 数值函数 ABS ACOS ASIN ATAN ATN2 AVG CEILING COUNT COS COT DEGREES EXP FLOOR LOG LOG10 MAX MIN PI POWER RADIANS RAND ROUND SIGN SIN SQRT SQUARE SUM TAN Date 日期函数 CURRENT_TIMESTAMP DATEADD DATEDIFF DATEFROMPARTS DATENAME DATEPART DAY GETDATE GETUTCDATE ISDATE MONTH SYSDATETIME YEAR 高级功能 CAST COALESCE CONVERT CURRENT_USER IIF ISNULL ISNUMERIC NULLIF SESSION_USER SESSIONPROPERTY SYSTEM_USER USER_NAME
MS Access 函数
String 字符串函数 Asc Chr Concat with & CurDir Format InStr InstrRev LCase Left Len LTrim Mid Replace Right RTrim Space Split Str StrComp StrConv StrReverse Trim UCase Numeric 数值函数 Abs Atn Avg Cos Count Exp Fix Format Int Max Min Randomize Rnd Round Sgn Sqr Sum Val Date 日期函数 Date DateAdd DateDiff DatePart DateSerial DateValue Day Format Hour Minute Month MonthName Now Second Time TimeSerial TimeValue Weekday WeekdayName Year 其他函数 CurrentUser Environ IsDate IsNull IsNumeric
SQL 快速参考手册

SQL 实例

SQL 实例 SQL 测验 SQL 练习

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SQL ORDER BY 关键词

SQL ORDER BY 关键词

ORDER BY 关键字用于对结果集按照一个列或者多个列进行排序。

ORDER BY 关键字默认按照升序对记录进行排序。如果需要按照降序对记录进行排序，您可以使用 DESC 关键字。

ORDER BY 语法

SELECT column1, column2, ...
FROM table_name
ORDER BY column1, column2, ... ASC|DESC;

演示数据库

以下是从 Northwind 示例数据库的 "客户(Customers)" 表中查询的内容：

CustomerID CustomerName ContactName Address City PostalCode Country
1

 Alfreds Futterkiste Maria Anders Obere Str. 57 Berlin 12209 Germany
2 Ana Trujillo Emparedados y helados Ana Trujillo Avda. de la Constitución 2222 México D.F. 05021 Mexico
3 Antonio Moreno Taquería Antonio Moreno Mataderos 2312 México D.F. 05023 Mexico
4

 Around the Horn Thomas Hardy 120 Hanover Sq. London WA1 1DP UK
5 Berglunds snabbköp Christina Berglund Berguvsvägen 8 Luleå S-958 22 Sweden

ORDER BY 实例

以下 SQL 语句从 "Customers" 表中选择所有客户，按 "Country" 列排序：

实例

SELECT * FROM Customers
ORDER BY Country;
亲自试一试 »

ORDER BY DESC 实例

以下 SQL 语句从 "Customers" 表中选择所有客户，按 "Country" 列降序排列：

实例

SELECT * FROM Customers
ORDER BY Country DESC;
亲自试一试 »

ORDER BY 多列实例

下面的 SQL 语句从 "customers" 表中选择所有客户，按 "Country" 和 "CustomerName" 列排序。这意味着它按国家/地区订购，但如果某些行具有相同的国家/地区，则按 CustomerName 列排序：

实例

SELECT * FROM Customers
ORDER BY Country, CustomerName;
亲自试一试 »

ORDER BY 多列实例 2

以下SQL语句从 "customers" 表中选择所有客户，按 "Country" 升序，按 "CustomerName" 列降序：

实例

SELECT * FROM Customers
ORDER BY Country ASC, CustomerName DESC;
亲自试一试 »

学习训练

练习题:

从Customers表中选择所有记录，按City列的字母顺序对结果进行排序。 p> 

SELECT * FROM Customers
 ;

开始练习


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