\u8457\u8005\u306f\u3001\u300cWrite for Donations\uff08\u5bc4\u4ed8\u3092\u52df\u308b\u305f\u3081\u306b\u66f8\u304f\uff09\u300d\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u4e00\u74b0\u3068\u3057\u3066\u3001Diversity in Tech Fund\u306b\u5bc4\u4ed8\u91d1\u3092\u8d08\u308b\u3053\u3068\u3092\u9078\u3073\u307e\u3057\u305f\u3002<\/p>\n
\u30ea\u30ec\u30fc\u30b7\u30e7\u30ca\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3068\u69cb\u9020\u5316\u30af\u30a8\u30ea\u8a00\u8a9e\uff08SQL\uff09\u3092\u4f7f\u7528\u3059\u308b\u969b\u306b\u306f\u3001\u30ea\u30ec\u30fc\u30b7\u30e7\u30ca\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u304b\u3089\u30c7\u30fc\u30bf\u3092\u683c\u7d0d\u3001\u7ba1\u7406\u3001\u53d6\u5f97\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002SQL\u306f\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u5185\u306b\u683c\u7d0d\u3055\u308c\u305f\u30c7\u30fc\u30bf\u3092\u305d\u306e\u307e\u307e\u53d6\u5f97\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
SQL\u3067\u306f\u3001\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u8a08\u7b97\u3084\u30c7\u30fc\u30bf\u306e\u64cd\u4f5c\u3092\u884c\u3046\u3053\u3068\u3082\u3067\u304d\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u3001\u95a2\u6570\u3092\u4f7f\u3063\u3066\u5546\u54c1\u306e\u4fa1\u683c\u3092\u6700\u3082\u8fd1\u3044\u30c9\u30eb\u306b\u4e38\u3081\u305f\u308a\u3001\u88fd\u54c1\u306e\u5e73\u5747\u8cfc\u5165\u6570\u3092\u8a08\u7b97\u3057\u305f\u308a\u3001\u7279\u5b9a\u306e\u8cfc\u5165\u54c1\u306e\u4fdd\u8a3c\u671f\u9593\u304c\u7d42\u4e86\u3059\u308b\u307e\u3067\u306e\u65e5\u6570\u3092\u6c42\u3081\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u30c1\u30e5\u30fc\u30c8\u30ea\u30a2\u30eb\u3067\u306f\u3001\u3055\u307e\u3056\u307e\u306aSQL\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u3001\u6570\u5b66\u7684\u306a\u8a08\u7b97\u3001\u6587\u5b57\u5217\u3068\u65e5\u4ed8\u306e\u64cd\u4f5c\u3001\u304a\u3088\u3073\u96c6\u8a08\u95a2\u6570\u3092\u4f7f\u7528\u3057\u305f\u8981\u7d04\u306e\u8a08\u7b97\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n
\u3053\u306e\u30ac\u30a4\u30c9\u306b\u5f93\u3046\u306b\u306f\u3001SQL\u30d9\u30fc\u30b9\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30ca\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\uff08RDBMS\uff09\u3092\u5b9f\u884c\u3059\u308b\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u304c\u5fc5\u8981\u3067\u3059\u3002\u3053\u306e\u30ac\u30a4\u30c9\u306e\u624b\u9806\u3068\u4f8b\u306f\u3001\u4ee5\u4e0b\u306e\u74b0\u5883\u3067\u691c\u8a3c\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n
Note<\/p>\n
\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u65e5\u672c\u8a9e\u306e\u8868\u73fe\u306b\u8a00\u3044\u63db\u3048\u307e\u3059\uff08\uff11\u3064\u306e\u30aa\u30d7\u30b7\u30e7\u30f3\u306e\u307f\uff09\uff1a
\n\u95a2\u6570\u306e\u4f7f\u7528\u65b9\u6cd5\u3092\u7df4\u7fd2\u3059\u308b\u305f\u3081\u306b\u3001\u3044\u304f\u3064\u304b\u306e\u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u304c\u30ed\u30fc\u30c9\u3055\u308c\u305f\u30c6\u30fc\u30d6\u30eb\u3092\u6301\u3064\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3082\u5fc5\u8981\u3067\u3059\u3002\u672c\u30ac\u30a4\u30c9\u5168\u4f53\u3067\u4f7f\u7528\u3059\u308b\u4f8b\u3068\u3057\u3066\u3001MySQL\u30b5\u30fc\u30d0\u30fc\u306b\u63a5\u7d9a\u3057\u3001\u30c6\u30b9\u30c8\u7528\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u4f5c\u6210\u3059\u308b\u8a73\u7d30\u306b\u3064\u3044\u3066\u306f\u3001\u300cMySQL\u3078\u306e\u63a5\u7d9a\u3068\u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u8a2d\u5b9a\u300d\u30bb\u30af\u30b7\u30e7\u30f3\u3092\u3054\u53c2\u7167\u304f\u3060\u3055\u3044\u3002<\/p>\n
\u3053\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001MySQL\u30b5\u30fc\u30d0\u30fc\u306b\u63a5\u7d9a\u3057\u3001\u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u4f5c\u6210\u3059\u308b\u3053\u3068\u3067\u3001\u3053\u306e\u30ac\u30a4\u30c9\u306e\u4f8b\u306b\u5f93\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u3082\u3057SQL\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30b7\u30b9\u30c6\u30e0\u304c\u30ea\u30e2\u30fc\u30c8\u30b5\u30fc\u30d0\u30fc\u4e0a\u3067\u52d5\u4f5c\u3057\u3066\u3044\u308b\u5834\u5408\u3001\u30ed\u30fc\u30ab\u30eb\u30de\u30b7\u30f3\u304b\u3089\u30b5\u30fc\u30d0\u30fc\u306bSSH\u3067\u63a5\u7d9a\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- ssh<\/span> sammy<\/mark>@your_server_ip<\/mark><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u305d\u308c\u304b\u3089\u3001MySQL\u30b5\u30fc\u30d0\u30fc\u30d7\u30ed\u30f3\u30d7\u30c8\u3092\u958b\u304d\u3001MySQL\u30e6\u30fc\u30b6\u30fc\u30a2\u30ab\u30a6\u30f3\u30c8\u306e\u540d\u524d\u3067\u3042\u308b\u300csammy\u300d\u3092\u4f7f\u3063\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- mysql -u<\/span> sammy<\/mark> -p<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u672c\u5c4b\u3068\u3044\u3046\u540d\u524d\u306e\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u4f5c\u6210\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- CREATE DATABASE bookstore;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304c\u6b63\u5e38\u306b\u4f5c\u6210\u3055\u308c\u305f\u5834\u5408\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u51fa\u529b\u304c\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\nQuery OK, 1 row affected (0.01 sec)<\/p>\n
<\/code><\/pre>\n\u66f8\u5e97\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u9078\u629e\u3059\u308b\u305f\u3081\u306b\u306f\u3001\u6b21\u306eUSE\u30b9\u30c6\u30fc\u30c8\u30e1\u30f3\u30c8\u3092\u5b9f\u884c\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- USE bookstore;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u6b21\u306e\u51fa\u529b\u3092\u53d7\u3051\u53d6\u308a\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\nDatabase changed<\/p>\n
<\/code><\/pre>\n\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u9078\u629e\u3057\u305f\u5f8c\u3001\u305d\u306e\u4e2d\u3067\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb\u3092\u4f5c\u6210\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u306e\u30ac\u30a4\u30c9\u3067\u306f\u3001\u7570\u306a\u308b\u8457\u8005\u306b\u3088\u308b\u672c\u3092\u8ca9\u58f2\u3059\u308b\u67b6\u7a7a\u306e\u66f8\u5e97\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n
\u66f8\u5e97\u306e\u30c6\u30fc\u30d6\u30eb\u5728\u5eab\u306b\u306f\u3001\u66f8\u7c4d\u306b\u95a2\u3059\u308b\u30c7\u30fc\u30bf\u304c\u542b\u307e\u308c\u307e\u3059\u3002\u4ee5\u4e0b\u306e\u5217\u304c\u4fdd\u6301\u3055\u308c\u307e\u3059\uff1a<\/p>\n
\n- book_id: This column holds the identifier for each book, represented by the int data type. This column will become the table\u2019s primary key, with each value becoming a unique identifier for its respective row.<\/li>\n
- author: This column holds the book author\u2019s name, expressed using the varchar data type with a maximum of 50 characters.<\/li>\n
- title: This column holds the purchased book\u2019s title, expressed using the varchar data type with a maximum of 200 characters.<\/li>\n
- introduction_date: Using the date data type, this column holds the date each book was introduced by the bookstore.<\/li>\n
- stock: This column holds the number of books the bookstore has in its inventory using the int integer data type.<\/li>\n
- price: This column stores the book\u2019s retail price using the decimal data type with a maximum of 5 values before the decimal point and 2 values after it.<\/li>\n<\/ul>\n
\u4ee5\u4e0b\u306e\u30b3\u30de\u30f3\u30c9\u3067\u30b5\u30f3\u30d7\u30eb\u30c6\u30fc\u30d6\u30eb\u3092\u4f5c\u6210\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- CREATE TABLE inventory (<\/span><\/li>\n
- book_id int,<\/li>\n
- author varchar(<\/span>50<\/span>)<\/span>,<\/li>\n
- title varchar(<\/span>200<\/span>)<\/span>,<\/li>\n
- introduction_date date,<\/li>\n
- stock int,<\/li>\n
- price decimal(<\/span>5<\/span>, 2<\/span>)<\/span>,<\/li>\n
- PRIMARY KEY (<\/span>book_id)<\/span><\/li>\n
- )<\/span>;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u3082\u3057\u4ee5\u4e0b\u306e\u51fa\u529b\u304c\u8868\u793a\u3055\u308c\u308c\u3070\u3001\u30c6\u30fc\u30d6\u30eb\u304c\u4f5c\u6210\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\nQuery OK, 0 rows affected (0.00 sec)<\/p>\n
<\/code><\/pre>\n\u305d\u306e\u5f8c\u3001\u6b21\u306eINSERT INTO\u64cd\u4f5c\u3092\u5b9f\u884c\u3057\u3066\u3001\u8cfc\u5165\u30c6\u30fc\u30d6\u30eb\u306b\u3044\u304f\u3064\u304b\u306e\u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u3092\u30ed\u30fc\u30c9\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- INSERT INTO inventory<\/li>\n
- VALUES<\/li>\n
- (<\/span>1<\/span>, ‘Oscar Wilde’<\/span>, ‘The Picture of Dorian Gray’<\/span>, ‘2022-10-01’<\/span>, 4<\/span>, 20.83<\/span>)<\/span>,<\/li>\n
- (<\/span>2<\/span>, ‘Jane Austen’<\/span>, ‘Pride and Prejudice’<\/span>, ‘2022-10-04’<\/span>, 12<\/span>, 42.13<\/span>)<\/span>,<\/li>\n
- (<\/span>3<\/span>, ‘Herbert George Wells’<\/span>, ‘The Time Machine’<\/span>, ‘2022-09-23’<\/span>, 7<\/span>, 21.99<\/span>)<\/span>,<\/li>\n
- (<\/span>4<\/span>, ‘Mary Shelley’<\/span>, ‘Frankenstein’<\/span>, ‘2022-07-23’<\/span>, 9<\/span>, 17.43<\/span>)<\/span>,<\/li>\n
- (<\/span>5<\/span>, ‘Mark Twain’<\/span>, ‘The Adventures of Huckleberry Finn’<\/span>, ‘2022-10-01’<\/span>, 14<\/span>, 23.15<\/span>)<\/span>;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u6307\u5b9a\u3055\u308c\u305f\u5024\u3092\u6301\u30645\u518a\u306e\u672c\u304c\u30a4\u30f3\u30d9\u30f3\u30c8\u30ea\u30fc\u30c6\u30fc\u30d6\u30eb\u306b\u8ffd\u52a0\u3055\u308c\u308bINSERT INTO\u64cd\u4f5c\u304c\u884c\u308f\u308c\u307e\u3059\u3002\u4ee5\u4e0b\u306e\u51fa\u529b\u306f\u3001\u3059\u3079\u3066\u306e5\u884c\u304c\u8ffd\u52a0\u3055\u308c\u305f\u3053\u3068\u3092\u793a\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\nQuery OK, 5 rows affected (0.00 sec) Records: 5 Duplicates: 0 Warnings: 0<\/p>\n
<\/code><\/pre>\n\u305d\u308c\u3067\u306f\u3001\u6b8b\u308a\u306e\u30ac\u30a4\u30c9\u3092\u30d5\u30a9\u30ed\u30fc\u3057\u3001SQL\u3067\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u6e96\u5099\u304c\u6574\u3044\u307e\u3057\u305f\u3002<\/p>\n
SQL\u95a2\u6570\u306e\u7406\u89e3<\/h2>\n
\u95a2\u6570\u306f\u30011\u3064\u307e\u305f\u306f\u8907\u6570\u306e\u5024\u3092\u53d7\u3051\u53d6\u308a\u3001\u30c7\u30fc\u30bf\u306b\u5bfe\u3057\u3066\u8a08\u7b97\u3084\u5909\u63db\u3092\u884c\u3044\u3001\u65b0\u3057\u3044\u5024\u3092\u7d50\u679c\u3068\u3057\u3066\u8fd4\u3059\u540d\u524d\u4ed8\u304d\u306e\u5f0f\u3067\u3059\u3002SQL\u306e\u95a2\u6570\u306f\u3001\u6570\u5b66\u306e\u95a2\u6570\u306b\u4f3c\u305f\u3088\u3046\u306a\u3082\u306e\u3067\u3059\u3002\u95a2\u6570log(x)\u306f\u3001\u3042\u308bx\u3092\u53d6\u308a\u3001x\u306e\u5bfe\u6570\u306e\u5024\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n
\u901a\u5e38\u3001\u30ea\u30ec\u30fc\u30b7\u30e7\u30ca\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304b\u3089\u60c5\u5831\u3092\u53d6\u5f97\u3059\u308b\u5834\u5408\uff08\u5909\u63db\u305b\u305a\u306b\uff09\u3001SELECT\u30af\u30a8\u30ea\u3092\u4f7f\u7528\u3057\u3001\u30b9\u30c6\u30fc\u30c8\u30e1\u30f3\u30c8\u3067\u5217\u540d\u3092\u6307\u5b9a\u3057\u3066\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306b\u5024\u3092\u8fd4\u3059\u3088\u3046\u8981\u6c42\u3057\u307e\u3059\u3002<\/p>\n
\u305f\u3068\u3048\u3070\u3001\u3082\u3063\u3068\u3082\u9ad8\u4fa1\u306a\u3082\u306e\u304b\u3089\u3082\u3063\u3068\u3082\u5b89\u4fa1\u306a\u3082\u306e\u307e\u3067\u9806\u306b\u4e26\u3079\u66ff\u3048\u3089\u308c\u305f\u3001\u3059\u3079\u3066\u306e\u672c\u306e\u30bf\u30a4\u30c8\u30eb\u3068\u4fa1\u683c\u3092\u53d6\u5f97\u3057\u305f\u3044\u5834\u5408\u306f\u3001\u6b21\u306e\u30b9\u30c6\u30fc\u30c8\u30e1\u30f3\u30c8\u3092\u5b9f\u884c\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT title<\/mark>, price<\/mark>, introduction_date<\/mark> FROM inventory ORDER BY price DESC;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u4ee5\u4e0b\u306e\u51fa\u529b\u3092\u53d7\u3051\u53d6\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\n+————————————+——-+——————-+ | title | price | introduction_date | +————————————+——-+——————-+ | Pride and Prejudice | 42.13 | 2022-10-04 | | The Adventures of Huckleberry Finn | 23.15 | 2022-10-01 | | The Time Machine | 21.99 | 2022-09-23 | | The Picture of Dorian Gray | 20.83 | 2022-10-01 | | Frankenstein | 17.43 | 2022-07-23 | +————————————+——-+——————-+ 5 rows in set (0.000 sec)<\/p>\n
<\/code><\/pre>\n\u3053\u306e\u6587\u3067\u306f\u3001\u30bf\u30a4\u30c8\u30eb\u3001\u4fa1\u683c\u3001\u304a\u3088\u3073\u5c0e\u5165\u65e5\u304c\u5217\u540d\u3068\u3057\u3066\u793a\u3055\u308c\u3001\u51fa\u529b\u7d50\u679c\u3067\u306f\u3001\u5404\u66f8\u7c4d\u3054\u3068\u306b\u305d\u308c\u3089\u306e\u5217\u304b\u3089\u53d6\u5f97\u3057\u305f\u5b8c\u5168\u306a\u66f8\u540d\u3001\u4fa1\u683c\u3001\u304a\u3088\u3073\u66f8\u7c4d\u304c\u66f8\u5e97\u306b\u5165\u8377\u3057\u305f\u65e5\u4ed8\u304c\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u63d0\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u305f\u3060\u3057\u3001\u4f55\u3089\u304b\u306e\u51e6\u7406\u3084\u64cd\u4f5c\u306e\u5f8c\u3067\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304b\u3089\u5024\u3092\u53d6\u5f97\u3059\u308b\u3053\u3068\u3082\u8003\u3048\u3089\u308c\u307e\u3059\u3002\u6700\u3082\u8fd1\u3044\u30c9\u30eb\u306b\u5207\u308a\u4e0a\u3052\u305f\u66f8\u7c4d\u306e\u4fa1\u683c\u3001\u5927\u6587\u5b57\u3067\u8868\u793a\u3055\u308c\u305f\u66f8\u7c4d\u306e\u30bf\u30a4\u30c8\u30eb\u3001\u307e\u305f\u306f\u6708\u3084\u65e5\u3092\u542b\u307e\u306a\u3044\u7d39\u4ecb\u5e74\u3002\u3053\u3046\u3044\u3063\u305f\u5834\u5408\u306b\u306f\u3001\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
SQL\u95a2\u6570\u306f\u3001\u64cd\u4f5c\u3059\u308b\u30c7\u30fc\u30bf\u306e\u30bf\u30a4\u30d7\u306b\u5fdc\u3058\u3066\u3044\u304f\u3064\u304b\u306e\u30b0\u30eb\u30fc\u30d7\u306b\u5927\u5225\u3055\u308c\u307e\u3059\u3002\u4ee5\u4e0b\u306f\u6700\u3082\u4e00\u822c\u7684\u306b\u4f7f\u7528\u3055\u308c\u308b\u95a2\u6570\u3067\u3059\u3002<\/p>\n
\n- Mathematical Functions: Functions operating on numerical values and performing computations, such as rounding, logarithms, square roots, or powers.<\/li>\n
- String Manipulation Functions: Functions operating on strings and text fields that perform text transformations, such as converting the text to uppercase, trimming, or replacing words within the values.<\/li>\n
- Date and Time Functions: Functions operating on fields holding dates. These functions perform computations and transformations, such as adding a number of days to the given date or taking just a year from the full date.<\/li>\n
- Aggregate Functions: A special case of mathematical functions that operate on values coming from multiple rows, such as calculating an average price for all rows.<\/li>\n<\/ul>\n\n
Note<\/p>\n
\u6ce8\u610f\uff1aMySQL\u3092\u542b\u3080\u307b\u3068\u3093\u3069\u306e\u95a2\u4fc2\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306f\u3001SQL\u306e\u6a19\u6e96\u30bb\u30c3\u30c8\u306b\u8ffd\u52a0\u306e\u64cd\u4f5c\u3092\u8ffd\u52a0\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u64cd\u4f5c\u306f\u3001\u305d\u308c\u305e\u308c\u306e\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30a8\u30f3\u30b8\u30f3\u306b\u56fa\u6709\u306e\u3082\u306e\u3067\u3059\u3002\u6a19\u6e96\u30bb\u30c3\u30c8\u5916\u306e\u591a\u304f\u306e\u95a2\u6570\u306f\u3001\u591a\u304f\u306e\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u540c\u69d8\u306b\u6a5f\u80fd\u3057\u307e\u3059\u304c\u3001\u4e00\u90e8\u306f\u7279\u5b9a\u306eRDBMS\u306b\u5236\u9650\u3055\u308c\u3066\u304a\u308a\u3001\u305d\u306e\u56fa\u6709\u306e\u6a5f\u80fd\u306b\u5bfe\u5fdc\u3057\u3066\u3044\u307e\u3059\u3002\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304c\u63d0\u4f9b\u3059\u308b\u95a2\u6570\u306b\u3064\u3044\u3066\u306f\u3001\u9078\u629e\u3057\u305f\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u3092\u53c2\u7167\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002MySQL\u306e\u5834\u5408\u306f\u3001\u300cBuilt-In Function and Operator Reference\u300d\u3067\u8a73\u7d30\u3092\u5b66\u3076\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/div>\n<\/div>\n\u4ee5\u4e0b\u306e\u4f8b\u306f\u3001SELECT\u30af\u30a8\u30ea\u3092\u4f7f\u7528\u3057\u3066\u66f8\u5e97\u306e\u5728\u5eab\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u4fa1\u683c\u5024\u3092\u5909\u66f4\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3055\u308c\u308b\u67b6\u7a7a\u306e\u5b58\u5728\u3057\u306a\u3044\u95a2\u6570\u3067\u3042\u308bEXAMPLE\u306e\u4e00\u822c\u7684\u306a\u69cb\u6587\u3092\u793a\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT EXAMPLE(<\/span>price)<\/span> AS new_price<\/mark> FROM inventory;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u95a2\u6570\uff08\u4f8b\u3048\u3070EXAMPLE\uff09\u306f\u3001\u30ab\u30e9\u30e0\u540d\uff08price\uff09\u3092\u62ec\u5f27\u3067\u56f2\u3093\u3060\u5f15\u6570\u3068\u3057\u3066\u53d7\u3051\u53d6\u308a\u307e\u3059\u3002\u3053\u306e\u30af\u30a8\u30ea\u306e\u90e8\u5206\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306b\u5bfe\u3057\u3066\u95a2\u6570EXAMPLE\u3092\u5b9f\u884c\u3057\u3001\u30ab\u30e9\u30e0price\u306e\u5024\u306b\u5bfe\u3057\u3066\u306e\u64cd\u4f5c\u7d50\u679c\u3092\u8fd4\u3059\u3053\u3068\u3092\u6307\u793a\u3057\u307e\u3059\u3002AS new_price\u306f\u3001\u30af\u30a8\u30ea\u306e\u671f\u9593\u4e2d\u306b\u8a08\u7b97\u3055\u308c\u305f\u5024\u306b\u4e00\u6642\u7684\u306a\u540d\u524d\uff08new_price\uff09\u3092\u5272\u308a\u5f53\u3066\u308b\u305f\u3081\u3001\u51fa\u529b\u3067\u95a2\u6570\u306e\u7d50\u679c\u3092\u533a\u5225\u3057\u3001WHERE\u3084ORDER BY\u7bc0\u3092\u4f7f\u7528\u3057\u3066\u8a08\u7b97\u3055\u308c\u305f\u5024\u3092\u53c2\u7167\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u4ee5\u4e0b\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u4e00\u822c\u7684\u306b\u4f7f\u7528\u3055\u308c\u308b\u8a08\u7b97\u3092\u884c\u3046\u305f\u3081\u306b\u6570\u5b66\u95a2\u6570\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n
\u6570\u5b66\u7684\u306a\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b<\/h2>\n
\u6570\u5b66\u95a2\u6570\u306f\u3001\u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u5185\u306e\u66f8\u7c4d\u306e\u4fa1\u683c\u3084\u5728\u5eab\u6570\u306a\u3069\u306e\u6570\u5024\u306b\u4f5c\u7528\u3057\u307e\u3059\u3002\u3053\u308c\u3089\u306f\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u5185\u3067\u8a08\u7b97\u3092\u884c\u3044\u3001\u7d50\u679c\u3092\u8981\u4ef6\u306b\u5408\u308f\u305b\u308b\u305f\u3081\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u30e9\u30a6\u30f3\u30c7\u30a3\u30f3\u30b0\u306fSQL\u3067\u6700\u3082\u3088\u304f\u4f7f\u7528\u3055\u308c\u308b\u6570\u5b66\u95a2\u6570\u306e\u4e00\u3064\u3067\u3059\u3002\u5168\u3066\u306e\u672c\u306e\u4fa1\u683c\u3092\u53d6\u5f97\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u6700\u5bc4\u308a\u306e\u6574\u6570\u30c9\u30eb\u306b\u4e38\u3081\u3089\u308c\u305f\u5024\u306b\u8208\u5473\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u306b\u306f\u3001\u30e9\u30a6\u30f3\u30c9\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u306e\u95a2\u6570\u306f\u4e38\u3081\u64cd\u4f5c\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n
\u4ee5\u4e0b\u306e\u30b9\u30c6\u30fc\u30c8\u30e1\u30f3\u30c8\u3092\u5b9f\u884c\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT title, price, ROUND(<\/span>price)<\/span> AS rounded_price<\/mark> FROM inventory;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u6b21\u306e\u51fa\u529b\u306f\u753b\u9762\u306b\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\n+————————————+——-+—————+ | title | price | rounded_price | +————————————+——-+—————+ | The Picture of Dorian Gray | 20.83 | 21 | | Pride and Prejudice | 42.13 | 42 | | The Time Machine | 21.99 | 22 | | Frankenstein | 17.43 | 17 | | The Adventures of Huckleberry Finn | 23.15 | 23 | +————————————+——-+—————+ 5 rows in set (0.000 sec)<\/p>\n
<\/code><\/pre>\n\u30af\u30a8\u30ea\u306f\u3001\u30bf\u30a4\u30c8\u30eb\u3068\u4fa1\u683c\u306e\u5217\u304b\u3089\u5024\u3092\u62bd\u51fa\u3057\u3001ROUND(price)\u95a2\u6570\u306e\u7d50\u679c\u3092\u6301\u3064\u4e00\u6642\u7684\u306arounded_price\u5217\u3068\u4e00\u7dd2\u306b\u8fd4\u3057\u307e\u3059\u3002\u3053\u306e\u95a2\u6570\u306f1\u3064\u306e\u5f15\u6570\u3001\u5217\u540d\uff08\u3053\u306e\u5834\u5408\u306f\u4fa1\u683c\uff09\u3092\u53d6\u308a\u3001\u30c6\u30fc\u30d6\u30eb\u5185\u306e\u305d\u306e\u5217\u306e\u5024\u3092\u6700\u3082\u8fd1\u3044\u6574\u6570\u5024\u306b\u4e38\u3081\u305f\u7d50\u679c\u3092\u8fd4\u3057\u307e\u3059\u3002<\/p>\n
\u4ee5\u4e0b\u306e\u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u4e38\u3081\u308b\u5c0f\u6570\u70b9\u4ee5\u4e0b\u306e\u6841\u6570\u3092\u5b9a\u7fa9\u3059\u308b\u305f\u3081\u306e\u8ffd\u52a0\u306e\u5f15\u6570\u3084\u3001\u5358\u4e00\u306e\u5217\u540d\u3067\u306f\u306a\u304f\u7b97\u8853\u6f14\u7b97\u3082\u53d7\u3051\u5165\u308c\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u4e38\u3081\u95a2\u6570\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT title, price, ROUND(<\/span>price * stock, 1<\/span>)<\/span> AS stock_price<\/mark> FROM inventory;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u4ee5\u4e0b\u306e\u51fa\u529b\u3092\u53d7\u3051\u53d6\u308a\u307e\u3059\u3002 (Anata wa shita no shutsuryoku o uketorimasu.)<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\n+————————————+——-+——-+————-+ | title | stock | price | stock_price | +————————————+——-+——-+————-+ | The Picture of Dorian Gray | 4 | 20.83 | 83.3 | | Pride and Prejudice | 12 | 42.13 | 505.6 | | The Time Machine | 7 | 21.99 | 153.9 | | Frankenstein | 9 | 17.43 | 156.9 | | The Adventures of Huckleberry Finn | 14 | 23.15 | 324.1 | +————————————+——-+——-+————-+ 5 rows in set (0.000 sec)<\/p>\n
<\/code><\/pre>\n`ROUND(\u4fa1\u683c * \u5728\u5eab\u6570, 1)`\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001\u307e\u305a\u5358\u4e00\u306e\u672c\u306e\u4fa1\u683c\u3092\u5728\u5eab\u306e\u518a\u6570\u3067\u4e57\u7b97\u3057\u3001\u305d\u306e\u7d50\u679c\u306e\u4fa1\u683c\u3092\u5c0f\u6570\u70b9\u4ee5\u4e0b1\u6841\u3067\u56db\u6368\u4e94\u5165\u3057\u307e\u3059\u3002\u305d\u306e\u7d50\u679c\u306f\u3001stock_price \u3068\u3044\u3046\u4e00\u6642\u7684\u306a\u5217\u3067\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
MySQL\u306b\u7d44\u307f\u8fbc\u307e\u308c\u3066\u3044\u308b\u4ed6\u306e\u6570\u5b66\u95a2\u6570\u306b\u306f\u3001\u4e09\u89d2\u95a2\u6570\u3001\u5e73\u65b9\u6839\u3001\u7d2f\u4e57\u3001\u5bfe\u6570\u3001\u6307\u6570\u95a2\u6570\u306a\u3069\u304c\u3042\u308a\u307e\u3059\u3002\u6570\u5b66\u95a2\u6570\u3092SQL\u3067\u4f7f\u7528\u3059\u308b\u65b9\u6cd5\u306b\u3064\u3044\u3066\u306f\u3001SQL\u30c1\u30e5\u30fc\u30c8\u30ea\u30a2\u30eb\u300c\u6570\u5b66\u7684\u306a\u5f0f\u3068\u96c6\u7d04\u95a2\u6570\u306e\u4f7f\u7528\u65b9\u6cd5\u300d\u3067\u8a73\u3057\u304f\u5b66\u3076\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001SQL\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u304b\u3089\u30c6\u30ad\u30b9\u30c8\u3092\u64cd\u4f5c\u3057\u307e\u3059\u3002<\/p>\n
\u6587\u5b57\u5217\u64cd\u4f5c\u95a2\u6570\u3092\u4f7f\u7528\u3057\u3066<\/h2>\n
SQL\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u95a2\u6570\u306f\u3001SQL\u30af\u30a8\u30ea\u306e\u51e6\u7406\u6642\u306b\u30c6\u30ad\u30b9\u30c8\u3092\u4fdd\u6301\u3059\u308b\u5217\u306e\u5024\u3092\u5909\u66f4\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u95a2\u6570\u306f\u3001\u4f8b\u3048\u3070\u3001\u5927\u6587\u5b57\u5c0f\u6587\u5b57\u306e\u5909\u63db\u3001\u8907\u6570\u306e\u5217\u304b\u3089\u30c7\u30fc\u30bf\u3092\u9023\u7d50\u3059\u308b\u3001\u307e\u305f\u306f\u691c\u7d22\u3068\u7f6e\u63db\u306e\u64cd\u4f5c\u3092\u5b9f\u884c\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
\u672c\u306e\u30bf\u30a4\u30c8\u30eb\u3092\u3059\u3079\u3066\u5c0f\u6587\u5b57\u306b\u5909\u63db\u3057\u3066\u53d6\u5f97\u3057\u3001\u6587\u5b57\u5217\u306e\u95a2\u6570\u3092\u4f7f\u7528\u3057\u59cb\u3081\u307e\u3059\u3002\u6b21\u306e\u6587\u3092\u5b9f\u884c\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT LOWER(<\/span>title)<\/span> AS title_lowercase<\/mark> FROM inventory;<\/span><\/li>\n<\/ol>\n
<\/code><\/pre>\n <\/p>\n
<\/code><\/pre>\n\u4ee5\u4e0b\u306e\u51fa\u529b\u306f\u753b\u9762\u306b\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
<\/code><\/pre>\nOutput<\/div>\n<\/code><\/pre>\n+————————————+ | title_lowercase | +————————————+ | the picture of dorian gray | | pride and prejudice | | the time machine | | frankenstein | | the adventures of huckleberry finn | +————————————+ 5 rows in set (0.001 sec)<\/p>\n
<\/code><\/pre>\nSQL\u95a2\u6570\u3067\u3042\u308bLOWER\u306f\u3001\u5358\u4e00\u306e\u5f15\u6570\u3092\u53d6\u308a\u3001\u305d\u306e\u5185\u5bb9\u3092\u5c0f\u6587\u5b57\u306b\u5909\u63db\u3057\u307e\u3059\u3002\u7d50\u679c\u306e\u30c7\u30fc\u30bf\u306f\u3001\u4e00\u6642\u7684\u306a\u5217\u3068\u3057\u3066title_lowercase\u3068\u3044\u3046\u540d\u524d\u3067\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n
\u4eca\u56de\u306f\u3001\u3059\u3079\u3066\u306e\u8457\u8005\u3092\u5927\u6587\u5b57\u306b\u5909\u63db\u3057\u3066\u53d6\u5f97\u3057\u3066\u304f\u3060\u3055\u3044\u3002\u4ee5\u4e0b\u306eSQL\u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3057\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n
<\/code><\/pre>\n\n- SELECT UPPER(<\/span>author