检查 MySQL 中是否存在表?
mysqlmysqli database
为了检查 MySQL 中是否存在表，您可以使用 INFORMATION_SCHEMA.TABLES。让我们首先创建一个表 −
mysql> create table Client_information -> ( -> Id int, -> Name varchar(10) -> ); Query OK, 0 rows affected (0.48 sec)
下面是使用 insert 命令在表中插入一些记录的查询 −
mysql> insert into Client_information values(1,'Larry'); Query OK, 1 row affected (0.14 sec) mysql> insert into Client_information values(2,'Mike'); Query OK, 1 row affected (0.17 sec) mysql> insert into Client_information values(3,'Sam'); Query OK, 1 row affected (0.19 sec)
以下是使用 select 语句显示表中的所有记录的查询 −
mysql> select * from Client_information;
这将产生以下输出 −
+------+-------+ | Id | Name | +------+-------+ | 1 | Larry | | 2 | Mike | | 3 | Sam | +------+-------+ 3 rows in set (0.00 sec)
以下是检查 MySQL 中表是否存在的查询 −
mysql> select * from information_schema.tables where table_name='Client_information';
根据输出状态，存在表"Client_information" −
+---------------+--------------+--------------------+------------+--------+---------+------------+------------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+--------------------+----------+----------------+---------------+ | TABLE_CATALOG | TABLE_SCHEMA | TABLE_NAME | TABLE_TYPE | ENGINE | VERSION | ROW_FORMAT | TABLE_ROWS | AVG_ROW_LENGTH | DATA_LENGTH | MAX_DATA_LENGTH | INDEX_LENGTH | DATA_FREE | AUTO_INCREMENT | CREATE_TIME | UPDATE_TIME | CHECK_TIME | TABLE_COLLATION | CHECKSUM | CREATE_OPTIONS | TABLE_COMMENT | +---------------+--------------+--------------------+------------+--------+---------+------------+------------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+--------------------+----------+----------------+---------------+ | def | sample | client_information | BASE TABLE | InnoDB | 10 | Dynamic | 4 | 4096 | 16384 | 0 | 0 | 0 | NULL | 2019-03-11 20:02:40 | NULL | NULL | utf8_general_ci | NULL | | | | def | test | client_information | BASE TABLE | InnoDB | 10 | Dynamic | 3 | 5461 | 16384 | 0 | 0 | 0 | NULL | 2019-04-03 02:28:31 | 2019-04-03 02:29:00 | NULL | utf8mb4_0900_ai_ci | NULL | | | +---------------+--------------+--------------------+------------+--------+---------+------------+------------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+--------------------+----------+----------------+---------------+ 2 rows in set (0.13 sec)
