以下是一些可以当工具书使用的参考语句~
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 datatypeor
ALTER TABLE table_name
DROP COLUMN column_name
AS (alias) 重命名
SELECT column_name AS column_alias
FROM table_nameor
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
CREATE INDEX index_name
ON table_name (column_name)or
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
DELETE FROM table_name
WHERE some_column=some_valueor
DELETE FROM table_name
(Note: Deletes the entire table!!)DELETE * FROM table_name
(Note: Deletes the entire table!!)
DROP DATABASE 删除数据库
DROP DATABASE database_name
DROP INDEX 删除索引
DROP INDEX table_name.index_name (SQL Server)
DROP INDEX index_name ON table_name (MS Access)
DROP INDEX index_name (DB2/Oracle)
ALTER TABLE table_name
DROP INDEX index_name (MySQL)
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,....)or
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_nameor
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