別名的常見用法是在檢索出的結果中重命名表的列字段(為了符合特定的報表要求或客戶需求)。有表Vendors代表供應商信息,vend_id供應商id、vend_name供應商名稱、vend_address供應商地址、vend_city供應商城市。 vend_id vend_name vend_address vend_city a001 tencent cloud address1 shenzhen a002 huawei cloud address2 dongguan a003 aliyun cloud address3 hangzhou a003 netease cloud address4 guangzhou 【問題】編寫 SQL 語句,從 Vendors 表中檢索vend_id、vend_name、vend_address 和 vend_city,將 vend_name重命名為 vname,將 vend_city 重命名為 vcity,將 vend_address重命名為 vaddress,按供應商名稱對結果進行升序排序。 【示例結果】返回vend_id 供應商id、vname 供應商名稱、vaddress供應商地址、vcity供應商城市。 vend_id vname vaddress vcity a003 aliyun cloud address3 hangzhou a002 huawei cloud address2 dongguan a003 netease cloud address4 guangzhou a001 tencent cloud address1 shenzhen
示例1
輸入
DROP TABLE IF EXISTS `Vendors`;
CREATE TABLE IF NOT EXISTS `Vendors` (
`vend_id` VARCHAR(255) NOT NULL COMMENT '供應商id',
`vend_name` VARCHAR(255) NOT NULL COMMENT '供應商名稱',
`vend_address` VARCHAR(255) NOT NULL COMMENT '供應商地址',
`vend_city` VARCHAR(255) NOT NULL COMMENT '供應商城市'
);
INSERT INTO `Vendors` VALUES ('a001','tencent cloud','address1','shenzhen'),
('a002','huawei cloud','address2','dongguan'),
('a003','aliyun cloud','address3','alibaba');
輸出
vend_id|vname|vaddress|vcity
a003|aliyun cloud|address3|alibaba
a002|huawei cloud|address2|dongguan
a001|tencent cloud|address1|shenzhen
加載中...