检查表是否存在而不在MySQL中使用“ select from”？

我们可以借助SHOW命令来实现。首先，我将在USE命令的帮助下使用数据库-

mysql> USE business;
Database changed

我们现在在“业务”数据库中。之后，我们可以检查该数据库有多少个表可用。查询如下-

mysql> SHOW tables;

以下是输出

+------------------------+
| Tables_in_business     |
+------------------------+
| addcolumntable         |
| autoincrement          |
| autoincrementtable     |
| bookindexes            |
| chardemo               |
| clonestudent           | 
| columnvaluenulldemo    |
| dateadddemo            |
| deletedemo             |
| deleterecord           |
| demo                   |
| demo1                  |
| demoascii              |
| demoauto               |
| demobcrypt             |
| demoemptyandnull       |
| demoint                |
| demoonreplace          |
| demoschema             |
| distinctdemo           |
| duplicatebookindexes   |
| duplicatefound         |
| employeetable          |
| existsrowdemo          |
| findandreplacedemo     |
| firsttable             |
| foreigntable           |
| foreigntabledemo       |
| groupdemo              |
| groupdemo1             |
| incasesensdemo         |
| int1demo               |
| intdemo                |
| latandlangdemo         |
| limitoffsetdemo        |
| milliseconddemo        |
| modifycolumnnamedemo   |
| modifydatatype         |
| moneydemo              |
| moviecollection        |
| mytable                |
| nonasciidemo           |
| nthrecorddemo          |
| nulldemo               |
| nullwithselect         |
| pasthistory            |
| presenthistory         |
| primarytable           |
| primarytable1          |
| primarytabledemo       |
| rownumberdemo          |
| rowstranspose          |
| rowstransposedemo      |
| secondtable            |
| sequencedemo           |
| smallintdemo           |
| spacecolumn            |
| student                |
| tblfirst               |
| tblstudent             |
| tbluni                 |
| textdemo               |
| texturl                |
| trailingandleadingdemo |
| transcationdemo        |
| unsigneddemo           |
| updtable               |
| varchardemo            |
| varchardemo1           |
| varchardemo2           |
| varcharurl             |
| whereconditon          |
+------------------------+
72 rows in set (0.03 sec)

下面显示了无需使用SELECT语句即可检查表是否存在的其他方法。

语法如下-

SHOW tables like ‘yourTableName’;

现在，我将应用上面的查询来检查数据库“ business”的表是否存在。

查询如下-

mysql> SHOW tables like 'tblstudent';

以下是输出

+---------------------------------+
| Tables_in_business (tblstudent) |
+---------------------------------+
| tblstudent                      |
+---------------------------------+
1 row in set (0.00 sec)

查看上面的输出，表“ tblstudent”在我的数据库中可见。表不存在的情况如下-

mysql> SHOW tables like 'sampledemo';
Empty set (0.00 sec)