MySQL内存表和临时表

Posted 2020-08-29

#mysql内存表和临时表

DROP TABLE IF EXISTS tbl;

CREATE TABLE tbl (
    id INT NOT NULL AUTO_INCREMENT,
    title VARCHAR (50) NOT NULL,
    author VARCHAR (50) NOT NULL,
    PRIMARY KEY (id)
) ENGINE = INNODB DEFAULT CHARSET = utf8;

INSERT INTO tbl(title, author) VALUES(‘Learn MySQL‘, ‘John Poul‘),(‘Learn Java‘, ‘Adbul S‘);

#内存表
DROP TABLE IF EXISTS mmr;

CREATE TEMPORARY TABLE mmr (
    #title TEXT NOT NULL#内存表不支持BLOB/TEXT列
    author VARCHAR (50) NOT NULL
) ENGINE = MEMORY DEFAULT CHARSET = utf8;

INSERT INTO mmr SELECT author FROM tbl;

SELECT author FROM mmr;

#临时表
DROP TABLE IF EXISTS tmp;

CREATE TEMPORARY TABLE tmp (
    title TEXT NOT NULL,
    author VARCHAR (50) NOT NULL
) ENGINE = MYISAM DEFAULT CHARSET = utf8;

INSERT INTO tmp (title, author) SELECT title, author FROM tbl;

SELECT title, author FROM tmp;