mysql常用整理
阿新 • • 發佈:2021-09-08
Mysql建表語句
SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0; -- ---------------------------- -- Table structure for mysql_table -- ---------------------------- DROP TABLE IF EXISTS `mysql_table`; CREATE TABLE `mysql_table` ( `id` bigint(20) NULL DEFAULT NULL COMMENT 'ID,主鍵', `name` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '姓名', `address` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '地址', `mobile` bigint(20) NULL DEFAULT NULL COMMENT '手機號', `other_info` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '其他資訊', `tenant_id` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '租戶ID', `created_by` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '建立者', `created_time` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '建立時間', `updated_time` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '更新時間', `updated_by` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NULL DEFAULT NULL COMMENT '更新者', `version` bigint(20) NULL DEFAULT NULL COMMENT '版本號,樂觀鎖', `is_deleted` bigint(20) NULL DEFAULT NULL COMMENT '是否刪除' ) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci ROW_FORMAT = Dynamic; -- ---------------------------- -- Records of mysql_table -- ---------------------------- INSERT INTO `mysql_table` VALUES (1, 'a', 'CQ', 123, 'info1', NULL, NULL, '20210819', NULL, NULL, NULL, NULL); INSERT INTO `mysql_table` VALUES (2, 'b', 'SZ', 123, 'info2', NULL, NULL, '20210819', NULL, NULL, NULL, NULL); SET FOREIGN_KEY_CHECKS = 1;
跨庫查詢:
select count(table1.id) from table1 INNER JOIN table2 on table1.name=table2.name
巢狀查詢
SELECT count(name) FROM table1 WHERE name IN (SELECT name FROM table2 )
小小測試一枚