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SQL 教程

SQL 主页 SQL 简介 SQL 语法 SQL 选择 SQL 选择 DISTINCT SQL WHERE SQL 排序 SQL AND SQL OR SQL NOT SQL 插入 SQL 空值 SQL 更新 SQL 删除 SQL 选择 TOP SQL 聚合函数 SQL MIN 和 MAX SQL COUNT SQL SUM SQL AVG SQL LIKE SQL 通配符 SQL IN SQL BETWEEN SQL 别名 SQL 连接 SQL 内连接 SQL 左连接 SQL 右连接 SQL 全连接 SQL 自连接 SQL UNION SQL 分组 SQL HAVING SQL EXISTS SQL ANY，ALL SQL 选择 INTO SQL 插入 SELECT SQL CASE SQL 空函数 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 备份数据库 SQL 创建表 SQL 删除表 SQL 修改表 SQL 约束 SQL 非空 SQL 唯一 SQL 主键 SQL 外键 SQL 检查 SQL 默认 SQL 索引 SQL 自增 SQL 日期 SQL 视图 SQL 注入 SQL 托管 SQL 数据类型

SQL 参考

SQL 关键字
ADD ADD CONSTRAINT ALL ALTER ALTER COLUMN ALTER TABLE 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
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 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 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 高级函数: 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
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 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 日期函数: CURRENT_TIMESTAMP DATEADD DATEDIFF DATEFROMPARTS DATENAME DATEPART DAY GETDATE GETUTCDATE ISDATE MONTH SYSDATETIME YEAR 高级函数 CAST COALESCE CONVERT CURRENT_USER IIF ISNULL ISNUMERIC NULLIF SESSION_USER SESSIONPROPERTY SYSTEM_USER USER_NAME
MS Access 函数
字符串函数: Asc Chr 使用 & 连接 CurDir Format InStr InstrRev LCase Left Len LTrim Mid Replace Right RTrim Space Split Str StrComp StrConv StrReverse Trim UCase 数值函数: Abs Atn Avg Cos Count Exp Fix Format Int Max Min Randomize Rnd Round Sgn Sqr Sum Val 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

SQL 例子

SQL 例子 SQL 编辑器 SQL 问答 SQL 练习 SQL Server SQL 集训营 SQL 证书

SQL 例子

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SQL 语法

从特定表（“Customers”）中选择所有记录

例子解释

SQL SELECT

SELECT 列 SELECT *

例子解释

SQL SELECT DISTINCT

SELECT DISTINCT

例子解释

SQL WHERE

WHERE 子句 文本字段 vs. 数值字段

例子解释

SQL AND、OR 和 NOT 运算符

AND OR NOT 组合 AND、OR 和 NOT

例子解释

SQL ORDER BY

ORDER BY ORDER BY DESC ORDER BY 多列

例子解释

SQL NULL 值

IS NULL 运算符 IS NOT NULL 运算符

例子解释

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SQL SELECT TOP

SELECT TOP LIMIT SELECT TOP PERCENT SELECT TOP 并添加 WHERE 子句

例子解释

SQL MIN() 和 MAX()

MIN() MAX()

例子解释

SQL COUNT、AVG() 和 SUM()

COUNT() AVG() SUM()

例子解释

SQL LIKE

LIKE - 选择所有以“a”开头的表行 LIKE - 选择所有以“a”结尾的表行 LIKE - 选择所有在任何位置包含“or”的表行 LIKE - 选择所有在第二位包含“r”的表行 LIKE - 选择所有以“a”开头并以“o”结尾的表行 LIKE - 选择所有不以“a”开头的表行

例子解释

SQL 通配符

使用 % 通配符 使用 _ 通配符 使用 [charlist] 通配符 使用 [!charlist] 通配符

例子解释

SQL IN

IN NOT IN

例子解释

SQL BETWEEN

BETWEEN NOT BETWEEN BETWEEN with IN BETWEEN 文本值 NOT BETWEEN 文本值

例子解释

SQL 别名

列的别名 两个别名 表的别名

例子解释

SQL 连接

INNER JOIN LEFT JOIN RIGHT JOIN 自连接

例子解释

SQL UNION

UNION UNION ALL 使用 WHERE 的 UNION 使用 WHERE 的 UNION ALL

例子解释

SQL GROUP BY

GROUP BY GROUP BY 和 ORDER BY 使用 JOIN 的 GROUP BY

例子解释

SQL HAVING

HAVING 和 GROUP BY HAVING 和 ORDER BY

例子解释

SQL EXISTS

EXISTS

例子解释

SQL ANY 和 ALL

ANY ALL

例子解释

SQL CASE

CASE 1 CASE 2

例子解释

SQL 注释

单行注释 单行注释在行尾 多行注释

例子解释

SQL 数据库

SQL 数据库教程可以在这里找到

SQL 创建数据库 SQL 删除数据库 SQL 备份数据库 SQL 创建表 SQL 删除表 SQL 修改表 SQL 约束 SQL 非空 SQL 唯一 SQL 主键 SQL 外键 SQL 检查 SQL 默认值 SQL 索引 SQL 自增 SQL 日期 SQL 视图 SQL 注入 SQL 托管

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