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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 实例

SQL 语法

Select all the records from a specific table ("Customers")

实例解析

SQL SELECT

SELECT Column SELECT *

实例解析

SQL SELECT DISTINCT

SELECT DISTINCT SELECT COUNT(DISTINCT column_name) SELECT COUNT(DISTINCT column_name) workaround for MS Access

实例解析

SQL WHERE

WHERE Clause Text Fields vs. Numeric Fields

实例解析

SQL AND, OR and NOT Operators

AND OR NOT Combining AND, OR and NOT

实例解析

SQL ORDER BY

ORDER BY ORDER BY DESC ORDER BY Several Columns

实例解析

SQL INSERT INTO

INSERT INTO Insert data in specific columns

实例解析

SQL NULL Values

IS NULL Operator IS NOT NULL Operator

实例解析

SQL Update

UPDATE Table UPDATE Multiple Records UPDATE Warning (if you omit the WHERE clause, all records will be updated)

实例解析

SQL DELETE

DELETE DELETE All Records

实例解析

SQL SELECT TOP

SELECT TOP LIMIT SELECT TOP PERCENT SELECT TOP and add a WHERE Clause

实例解析

SQL MIN() and MAX()

MIN() MAX()

实例解析

SQL COUNT, AVG() and SUM()

COUNT() AVG() SUM()

实例解析

SQL LIKE

LIKE - select all table rows starting with "a" LIKE - select all table rows ending with "a" LIKE - select all table rows that have "or" in any position LIKE - select all table rows that have "r" in the second position LIKE - select all table rows that starts with "a" and ends with "o" LIKE - select all table rows that does NOT start with "a"

实例解析

SQL Wildcards

Using the % Wildcard Using the _ Wildcard Using the [charlist] Wildcard Using the [!charlist] Wildcard

实例解析

SQL IN

IN NOT IN

实例解析

SQL BETWEEN

BETWEEN NOT BETWEEN BETWEEN with IN BETWEEN Text Values NOT BETWEEN Text Values

实例解析

SQL Aliases

Alias for Columns Two Aliases Alias for Tables

实例解析

SQL Joins

INNER JOIN LEFT JOIN RIGHT JOIN Self JOIN

实例解析

SQL UNION

UNION UNION ALL UNION With WHERE UNION ALL With WHERE

实例解析

SQL GROUP BY

GROUP BY GROUP BY and ORDER BY GROUP BY With JOIN

实例解析

SQL HAVING

HAVING and GROUP BY HAVING and ORDER BY

实例解析

SQL EXISTS

EXISTS

实例解析

SQL ANY and ALL

ANY ALL

实例解析

SQL INSERT INTO SELECT

INSERT INTO SELECT INSERT INTO SELECT with WHERE

实例解析

SQL CASE

CASE 1 CASE 2

实例解析

SQL Comments

Single Line Comments Single Line Comments At The End Of a Line Multi-line Comments

实例解析

SQL Database

SQL Database tutorials can be found here:

SQL Create DB SQL Drop DB SQL Backup DB SQL Create Table SQL Drop Table SQL Alter Table SQL Constraints SQL Not Null SQL Unique SQL Primary Key SQL Foreign Key SQL Check SQL Default SQL Index SQL Auto Increment SQL Dates SQL Views SQL Injection SQL Hosting

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