SQL的学习
Posted 0岁的数据分析师
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SQL的学习之路，主要参考资料是：
操作使用的数据库为Access及mysql。
数据采用的是SQL必知必会中的数据（最下方可以下载数据）。其有5个表，表的关系如下：
1 # 这里补充下，MySQL创建该数据库（2017.5.17）,复制到MySQL创建执行创建即可（数据来源于《SQL必知必会》）； 2 3 -- ---------------------- 4 -- Create Customers table 5 -- ---------------------- 6 CREATE TABLE Customers 7 ( 8 cust_id char(10) NOT NULL , 9 cust_name char(50) NOT NULL , 10 cust_address char(50) NULL , 11 cust_city char(50) NULL , 12 cust_state char(5) NULL , 13 cust_zip char(10) NULL , 14 cust_country char(50) NULL , 15 cust_contact char(50) NULL , 16 cust_email char(255) NULL 17 ); 18 19 -- ----------------------- 20 -- Create OrderItems table 21 -- ----------------------- 22 CREATE TABLE OrderItems 23 ( 24 order_num int NOT NULL , 25 order_item int NOT NULL , 26 prod_id char(10) NOT NULL , 27 quantity int NOT NULL , 28 item_price decimal(8,2) NOT NULL 29 ); 30 31 32 -- ------------------- 33 -- Create Orders table 34 -- ------------------- 35 CREATE TABLE Orders 36 ( 37 order_num int NOT NULL , 38 order_date datetime NOT NULL , 39 cust_id char(10) NOT NULL 40 ); 41 42 -- --------------------- 43 -- Create Products table 44 -- --------------------- 45 CREATE TABLE Products 46 ( 47 prod_id char(10) NOT NULL , 48 vend_id char(10) NOT NULL , 49 prod_name char(255) NOT NULL , 50 prod_price decimal(8,2) NOT NULL , 51 prod_desc text NULL 52 ); 53 54 -- -------------------- 55 -- Create Vendors table 56 -- -------------------- 57 CREATE TABLE Vendors 58 ( 59 vend_id char(10) NOT NULL , 60 vend_name char(50) NOT NULL , 61 vend_address char(50) NULL , 62 vend_city char(50) NULL , 63 vend_state char(5) NULL , 64 vend_zip char(10) NULL , 65 vend_country char(50) NULL 66 ); 67 68 69 -- ------------------- 70 -- Define primary keys 71 -- ------------------- 72 ALTER TABLE Customers ADD PRIMARY KEY (cust_id); 73 ALTER TABLE OrderItems ADD PRIMARY KEY (order_num, order_item); 74 ALTER TABLE Orders ADD PRIMARY KEY (order_num); 75 ALTER TABLE Products ADD PRIMARY KEY (prod_id); 76 ALTER TABLE Vendors ADD PRIMARY KEY (vend_id); 77 78 79 -- ------------------- 80 -- Define foreign keys 81 -- ------------------- 82 ALTER TABLE OrderItems ADD CONSTRAINT FK_OrderItems_Orders FOREIGN KEY (order_num) REFERENCES Orders (order_num); 83 ALTER TABLE OrderItems ADD CONSTRAINT FK_OrderItems_Products FOREIGN KEY (prod_id) REFERENCES Products (prod_id); 84 ALTER TABLE Orders ADD CONSTRAINT FK_Orders_Customers FOREIGN KEY (cust_id) REFERENCES Customers (cust_id); 85 ALTER TABLE Products ADD CONSTRAINT FK_Products_Vendors FOREIGN KEY (vend_id) REFERENCES Vendors (vend_id); 86 87 # 插入数据 88 -- ------------------------ 89 -- Populate Customers table 90 -- ------------------------ 91 INSERT INTO Customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact, cust_email) 92 VALUES(\'1000000001\', \'Village Toys\', \'200 Maple Lane\', \'Detroit\', \'MI\', \'44444\', \'USA\', \'John Smith\', \'sales@villagetoys.com\'); 93 INSERT INTO Customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact) 94 VALUES(\'1000000002\', \'Kids Place\', \'333 South Lake Drive\', \'Columbus\', \'OH\', \'43333\', \'USA\', \'Michelle Green\'); 95 INSERT INTO Customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact, cust_email) 96 VALUES(\'1000000003\', \'Fun4All\', \'1 Sunny Place\', \'Muncie\', \'IN\', \'42222\', \'USA\', \'Jim Jones\', \'jjones@fun4all.com\'); 97 INSERT INTO Customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact, cust_email) 98 VALUES(\'1000000004\', \'Fun4All\', \'829 Riverside Drive\', \'Phoenix\', \'AZ\', \'88888\', \'USA\', \'Denise L. Stephens\', \'dstephens@fun4all.com\'); 99 INSERT INTO Customers(cust_id, cust_name, cust_address, cust_city, cust_state, cust_zip, cust_country, cust_contact) 100 VALUES(\'1000000005\', \'The Toy Store\', \'4545 53rd Street\', \'Chicago\', \'IL\', \'54545\', \'USA\', \'Kim Howard\'); 101 102 -- ---------------------- 103 -- Populate Vendors table 104 -- ---------------------- 105 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 106 VALUES(\'BRS01\',\'Bears R Us\',\'123 Main Street\',\'Bear Town\',\'MI\',\'44444\', \'USA\'); 107 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 108 VALUES(\'BRE02\',\'Bear Emporium\',\'500 Park Street\',\'Anytown\',\'OH\',\'44333\', \'USA\'); 109 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 110 VALUES(\'DLL01\',\'Doll House Inc.\',\'555 High Street\',\'Dollsville\',\'CA\',\'99999\', \'USA\'); 111 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 112 VALUES(\'FRB01\',\'Furball Inc.\',\'1000 5th Avenue\',\'New York\',\'NY\',\'11111\', \'USA\'); 113 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 114 VALUES(\'FNG01\',\'Fun and Games\',\'42 Galaxy Road\',\'London\', NULL,\'N16 6PS\', \'England\'); 115 INSERT INTO Vendors(vend_id, vend_name, vend_address, vend_city, vend_state, vend_zip, vend_country) 116 VALUES(\'JTS01\',\'Jouets et ours\',\'1 Rue Amusement\',\'Paris\', NULL,\'45678\', \'France\'); 117 118 -- ----------------------- 119 -- Populate Products table 120 -- ----------------------- 121 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 122 VALUES(\'BR01\', \'BRS01\', \'8 inch teddy bear\', 5.99, \'8 inch teddy bear, comes with cap and jacket\'); 123 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 124 VALUES(\'BR02\', \'BRS01\', \'12 inch teddy bear\', 8.99, \'12 inch teddy bear, comes with cap and jacket\'); 125 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 126 VALUES(\'BR03\', \'BRS01\', \'18 inch teddy bear\', 11.99, \'18 inch teddy bear, comes with cap and jacket\'); 127 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 128 VALUES(\'BNBG01\', \'DLL01\', \'Fish bean bag toy\', 3.49, \'Fish bean bag toy, complete with bean bag worms with which to feed it\'); 129 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 130 VALUES(\'BNBG02\', \'DLL01\', \'Bird bean bag toy\', 3.49, \'Bird bean bag toy, eggs are not included\'); 131 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 132 VALUES(\'BNBG03\', \'DLL01\', \'Rabbit bean bag toy\', 3.49, \'Rabbit bean bag toy, comes with bean bag carrots\'); 133 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 134 VALUES(\'RGAN01\', \'DLL01\', \'Raggedy Ann\', 4.99, \'18 inch Raggedy Ann doll\'); 135 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 136 VALUES(\'RYL01\', \'FNG01\', \'King doll\', 9.49, \'12 inch king doll with royal garments and crown\'); 137 INSERT INTO Products(prod_id, vend_id, prod_name, prod_price, prod_desc) 138 VALUES(\'RYL02\', \'FNG01\', \'Queen doll\', 9.49, \'12 inch queen doll with royal garments and crown\'); 139 140 -- --------------------- 141 -- Populate Orders table 142 -- --------------------- 143 INSERT INTO Orders(order_num, order_date, cust_id) 144 VALUES(20005, \'2012-05-01\', \'1000000001\'); 145 INSERT INTO Orders(order_num, order_date, cust_id) 146 VALUES(20006, \'2012-01-12\', \'1000000003\'); 147 INSERT INTO Orders(order_num, order_date, cust_id) 148 VALUES(20007, \'2012-01-30\', \'1000000004\'); 149 INSERT INTO Orders(order_num, order_date, cust_id) 150 VALUES(20008, \'2012-02-03\', \'1000000005\'); 151 INSERT INTO Orders(order_num, order_date, cust_id) 152 VALUES(20009, \'2012-02-08\', \'1000000001\'); 153 154 -- ------------------------- 155 -- Populate OrderItems table 156 -- ------------------------- 157 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 158 VALUES(20005, 1, \'BR01\', 100, 5.49); 159 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 160 VALUES(20005, 2, \'BR03\', 100, 10.99); 161 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 162 VALUES(20006, 1, \'BR01\', 20, 5.99); 163 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 164 VALUES(20006, 2, \'BR02\', 10, 8.99); 165 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 166 VALUES(20006, 3, \'BR03\', 10, 11.99); 167 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 168 VALUES(20007, 1, \'BR03\', 50, 11.49); 169 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 170 VALUES(20007, 2, \'BNBG01\', 100, 2.99); 171 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 172 VALUES(20007, 3, \'BNBG02\', 100, 2.99); 173 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 174 VALUES(20007, 4, \'BNBG03\', 100, 2.99); 175 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 176 VALUES(20007, 5, \'RGAN01\', 50, 4.49); 177 INSERT INTO OrderItems(order_num, order_item, prod_id, quantity, item_price) 178 VALUES(20008, 1, \'RGAN01\', 5, 4.99); 179 INSERT INTO以上是关于SQL的学习的主要内容，如果未能解决你的问题，请参考以下文章以下代码片段是不是容易受到 Rails 5 中 SQL 注入的影响？