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Memo

■データ操作

データベース作成
CREATE DATABASE test DEFAULT CHARACTER SET utf8mb4;


データベース削除
DROP DATABASE test;


データベース仕様確認
SHOW CREATE DATABASE test;


テーブル作成
CREATE TABLE address(
  no   INT,
  name VARCHAR(80),
  tel  VARCHAR(80)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT 'アドレス';


テーブル名変更
ALTER TABLE address RENAME TO address2;
RENAME TABLE address TO address2;


MySQLの「ALTER TABLE RENAME」と「RENAME TABLE」 - なからなLife
https://atsuizo.hatenadiary.jp/entry/2016/06/16/100000

テーブル削除
DROP TABLE address;


テーブル仕様確認
SHOW COLUMNS FROM address;
SHOW FULL COLUMNS FROM address;
SHOW CREATE TABLE address;


登録
INSERT INTO address(no, name, tel) VALUES(1, '山田太郎', '090-1234-5678');
INSERT INTO address VALUES(1, '山田太郎', '090-1234-5678');


表示
SELECT name, tel FROM address;
SELECT token, COUNT(*) FROM devices GROUP BY token;


更新
UPDATE address SET name = '山田健二' WHERE name = '山田太郎';
UPDATE address SET name = '山田健二', tel = '090-2345-6789' WHERE name = '山田太郎';


削除
DELETE FROM address WHERE name = '山田太郎';
DELETE FROM products WHERE id >= 5001;


複製
INSERT INTO address_test SELECT * FROM address WHERE no >= 3;


オートインクリメントをリセット
ALTER TABLE products AUTO_INCREMENT = 0;


日時をフォーマットして表示
SELECT DATE_FORMAT(created, '%Y-%m-%d %H:%i:%s') AS created FROM histories GROUP BY created ORDER BY id DESC LIMIT 100;


日付をフォーマットして表示
SELECT DATE_FORMAT(created, '%Y-%m-%d') AS created FROM histories GROUP BY created ORDER BY id DESC LIMIT 100;


日付ごとにランキング
SELECT
    DATE_FORMAT(created, '%Y-%m-%d') AS created,
    COUNT(*) AS count
FROM
    histories
GROUP BY
    DATE_FORMAT(created, '%Y-%m-%d')
ORDER BY
    count DESC
LIMIT
    100;


連結して表示
SELECT
    histories.created_at,
    histories.user_id,
    histories.device_id,
    devices.token
FROM
    histories LEFT JOIN devices ON histories.device_id = devices.id
WHERE
    histories.detail IS NULL
ORDER BY
    histories.id
LIMIT
    100
;

SELECT
    devices.token,
    COUNT(devices.token)
FROM
    histories LEFT JOIN devices ON histories.device_id = devices.id
WHERE
    histories.detail IS NULL AND histories.created_at = '2019-02-08 15:02:29'
GROUP BY
    devices.token
;


データ件数を一括確認
SELECT
    table_name, table_rows from information_schema.TABLES
WHERE
    table_schema = '対象データベース名'
;


MySQLで全テーブルのレコード数を一覧表示する - Qiita
https://qiita.com/isobecky74/items/6efff247484f8e4fccae

インデックスを確認
SHOW INDEX FROM histories;


インデックスを一括確認
SELECT
    TABLE_SCHEMA, TABLE_NAME, INDEX_NAME, COLUMN_NAME, SEQ_IN_INDEX
FROM
    information_schema.STATISTICS
WHERE
    TABLE_SCHEMA = '対象データベース名'
ORDER BY
    TABLE_SCHEMA, TABLE_NAME,INDEX_NAME, SEQ_IN_INDEX
;


MySQLでDB内の全てのインデックスの一覧をCSV出力する｜エンジニア初心者の備忘録
http://rigil.iku4.com/mysql_command/index
Memo

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