TiDB入门（三）：简单测试

$ mysql -uroot -h192.168.13.157 -P 4000 math_stackexchange < math_stackexchange.sql
$ mysql -uroot -h192.168.13.157 -P 4000 stackoverflow < stackoverflow.sql

CREATE TABLE `comments` (
	`Id` BIGINT(20) NOT NULL AUTO_INCREMENT,
	`PostId` BIGINT(20) NULL DEFAULT NULL,
	`Score` INT(11) NULL DEFAULT NULL,
	`Text` TEXT NULL,
	`CreationDate` DATETIME NULL DEFAULT NULL,
	`UserId` BIGINT(20) NULL DEFAULT NULL,
	`UserDisplayName` VARCHAR(100) NULL,
	PRIMARY KEY (`Id`),
	INDEX `CreationDate` (`CreationDate`)
)
COLLATE='utf8mb4_bin'
ENGINE=InnoDB
;

CREATE TABLE `users` (
	`Id` BIGINT(20) NOT NULL AUTO_INCREMENT,
	`Reputation` INT(11) NULL DEFAULT NULL,
	`CreationDate` DATETIME NULL DEFAULT NULL,
	`DisplayName` VARCHAR(100) NULL,
	`LastAccessDate` DATETIME NULL DEFAULT NULL,
	`WebsiteUrl` VARCHAR(255) NULL,
	`Location` VARCHAR(100) NULL,
	`AboutMe` TEXT NULL,
	`Views` INT(11) NULL DEFAULT NULL,
	`UpVotes` INT(11) NULL DEFAULT NULL,
	`DownVotes` INT(11) NULL DEFAULT NULL,
	`AccountId` BIGINT(20) NULL DEFAULT NULL,
	`ProfileImageUrl` VARCHAR(255) NULL,
	PRIMARY KEY (`Id`),
	INDEX `CreationDate` (`CreationDate`)
)
COLLATE='utf8mb4_bin'
ENGINE=InnoDB
;

$ SELECT COUNT(0) FROM [表名]

$ select count(0) from [表名] where CreationDate > '2017-01-01'

$ select count(0) from math_stackexchange.users where views > 10
$ select count(0) from math_stackexchange.comments where score > 3
$ select count(0) from stackoverflow.users where views > 10
$ select count(0) from stackoverflow.comments where score > 3

$ select count(0) from math_stackexchange.comments as a join math_stackexchange.users as b on a.UserId = b.Id where a.CreationDate > '2017-01-01' and  b.views > 10
$ select count(0) from stackoverflow.comments as a join stackoverflow.users as b on a.UserId = b.Id where a.CreationDate > '2017-01-01' and  b.views > 10