🔖 SQL必知必会源码

codes/mysql/sql必知必会示例/select.sql

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+/**
+ * Mysql 查询示例
+ * @author Zhang Peng
+ * @date 2018/5/5
+ */
+
+-- -------------------------------------------
+-- 查询数据
+-- -------------------------------------------
+
+-- 查询单列
+SELECT prod_name
+FROM products;
+
+-- 查询多列
+SELECT prod_id, prod_name, prod_price
+FROM products;
+
+-- 查询所有列
+SELECT *
+FROM products;
+
+-- 查询不同的值
+SELECT DISTINCT vend_id
+FROM products;
+
+-- 限制结果
+-- 返回前 5 行（1）
+SELECT *
+FROM products
+LIMIT 5;
+-- 返回前 5 行（2）
+SELECT *
+FROM products
+LIMIT 0, 5;
+-- 返回第 3 ~ 5 行
+SELECT *
+FROM products
+LIMIT 2, 3;
+
+-- -------------------------------------------
+-- 查询数据排序
+-- -------------------------------------------
+
+-- 默认升序
+SELECT prod_price FROM products
+ORDER BY prod_price;
+
+-- 指定多个列的排序方向
+SELECT * FROM products
+ORDER BY prod_price DESC, prod_name ASC;
+
+
+-- -------------------------------------------
+-- IN、BETWEEN
+-- -------------------------------------------
+
+-- IN 示例
+SELECT *
+FROM products
+WHERE vend_id IN ('DLL01', 'BRS01');
+
+-- BETWEEN 示例
+SELECT *
+FROM products
+WHERE prod_price BETWEEN 3 AND 5;
+
+-- -------------------------------------------
+-- AND、OR、NOT
+-- -------------------------------------------
+
+-- AND 示例
+SELECT prod_id, prod_name, prod_price
+FROM products
+WHERE vend_id = 'DLL01' AND prod_price <= 4;
+
+-- OR 示例
+SELECT prod_id, prod_name, prod_price
+FROM products
+WHERE vend_id = 'DLL01' OR vend_id = 'BRS01';
+
+-- OR 示例
+SELECT prod_id, prod_name, prod_price
+FROM products
+WHERE vend_id = 'DLL01' OR vend_id = 'BRS01';
+
+-- AND 优先级高于 OR 示例（比较两条 sql 结果的差异）
+SELECT *
+FROM products
+WHERE vend_id = 'DLL01' OR vend_id = 'BRS01' AND prod_price >= 10;
+SELECT *
+FROM products
+WHERE (vend_id = 'DLL01' OR vend_id = 'BRS01') AND prod_price >= 10;
+
+-- NOT 示例
+SELECT *
+FROM products
+WHERE prod_price NOT BETWEEN 3 AND 5;