作者：丶平凡世界
来源：SQL数据库开发
今天开始一个新的基础系列，是有关SQL基础知识的，以下是一些可以当工具书使用的参考语句，都是固定写法，需要的时候可以拿出来参考一下，一些不懂的可以暂时先跳过，紫色代码均是SQL语句的关键字~
AND / OR 并且/或
SELECT column_name(s) FROM table_name WHERE condition AND|OR condition
ALTER TABLE 修改表
ALTER TABLE table_name ADD column_name datatype --或 ALTER TABLE table_name DROP COLUMN column_name
AS (alias) 重命名
--对列名进行重命名 SELECT column_name AS column_alias FROM table_name --对表名进行重命名 SELECT column_name FROM table_name AS table_alias
BETWEEN...AND... 在某个区间
SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2
CREATE DATABASE 创建数据库
CREATE DATABASE database_name
CREATE TABLE 创建表
CREATE TABLE table_name ( column_name1 data_type, column_name2 data_type, column_name2 data_type, ... )
CREATE INDEX 创建索引
--创建普通索引 CREATE INDEX index_name ON table_name (column_name) --创建唯一索引 CREATE UNIQUE INDEX index_name ON table_name (column_name)
CREATE VIEW 创建视图
CREATE VIEW view_name AS SELECT column_name(s) FROM table_name WHERE condition
DELETE 删除
--带条件的删除 DELETE FROM table_name WHERE some_column=some_value --不带条件的删除 DELETE FROM table_name
DROP DATABASE 删除数据库
DROP DATABASE database_name
DROP INDEX 删除索引
--SQL Server的写法 DROP INDEX table_name.index_name --DB2/Oracle的写法 DROP INDEX index_name --Mysql的写法 ALTER TABLE table_name DROP INDEX index_name
DROP TABLE 删除表
DROP TABLE table_name
GROUP BY 分组
SELECT column_name, aggregate_function(column_name) FROM table_name WHERE column_name operator value GROUP BY column_name
HAVING 分组过滤条件
SELECT column_name, aggregate_function(column_name) FROM table_name WHERE column_name operator value GROUP BY column_name HAVING aggregate_function(column_name) operator value
IN 在某些固定值中查找
SELECT column_name(s) FROM table_name WHERE column_name IN (value1,value2,..)
INSERT INTO 插入表
INSERT INTO table_name VALUES (value1, value2, value3,....) --或 INSERT INTO table_name (column1, column2, column3,...) VALUES (value1, value2, value3,....)
INNER JOIN 内连接
SELECT column_name(s) FROM table_name1 INNER JOIN table_name2 ON table_name1.column_name=table_name2.column_name
LEFT JOIN 左连接
SELECT column_name(s) FROM table_name1 LEFT JOIN table_name2 ON table_name1.column_name=table_name2.column_name
RIGHT JOIN 右连接
SELECT column_name(s) FROM table_name1 RIGHT JOIN table_name2 ON table_name1.column_name=table_name2.column_name
FULL JOIN 全连接
SELECT column_name(s) FROM table_name1 FULL JOIN table_name2 ON table_name1.column_name=table_name2.column_name
LIKE 模糊匹配
SELECT column_name(s) FROM table_name WHERE column_nameLIKE pattern
ORDER BY 排序
SELECT column_name(s) FROM table_name ORDER BY column_name [ASC|DESC]
SELECT 查找
SELECT column_name(s) FROM table_name
SELECT * 查找表的所有字段
SELECT * FROM table_name
SELECT DISTINCT 查找去除重复的列
SELECT DISTINCT column_name(s) FROM table_name
SELECT INTO 查询结果插入表
SELECT * INTO new_table_name [IN externaldatabase] FROM old_table_name --或 SELECT column_name(s) INTO new_table_name [IN externaldatabase] FROM old_table_name
SELECT TOP 查询前N条记录
SELECT TOP number|percent column_name(s) FROM table_name
TRUNCATE TABLE 清空表
TRUNCATE TABLE table_name
UNION 去重并集
SELECT column_name(s) FROM table_name1 UNION SELECT column_name(s) FROM table_name2
UNION ALL 不去重并集
SELECT column_name(s) FROM table_name1 UNION ALL SELECT column_name(s) FROM table_name2
UPDATE 更新
UPDATE table_name SET column1=value, column2=value,... WHERE some_column=some_value
WHERE 条件过滤
SELECT column_name(s) FROM table_name WHERE column_name operator value