blocks|key|650909|text|我已经成功地执行了一段代码，该代码在表不存在时始终有效且不会产生错误：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|650910|SELECT+Count(*)
INTO+@exists
FROM+information_schema.tables+
WHERE+table_schema+=+[DATABASE_NAME]
++++AND+table_type+=+'BASE+TABLE'
++++AND+table_name+=+'video_top_day';

SET+@query+=+If(@exists>0,
++++'RENAME+TABLE+video_top_day+TO+video_top_day_for_delete',
++++'SELECT+\'nothing+to+rename\'+status');

PREPARE+stmt+FROM+@query;

EXECUTE+stmt;|code-block|syntax|javascript|650911|当您不想手动替换[DATABASE+NAME]时，可以使用以下变量|offset|length|style|CODE|650912|SELECT+DATABASE()+INTO+@db_name+FROM+DUAL;|650913|entityMap^0|0|0|8|F|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I've managed to execute a code that always works and generates no errors when the table doesn't exist:

<pre><code>SELECT Count(*)
INTO @exists
FROM information_schema.tables 
WHERE table_schema = [DATABASE_NAME]
 AND table_type = 'BASE TABLE'
 AND table_name = 'video_top_day';

SET @query = If(@exists&gt;0,
 'RENAME TABLE video_top_day TO video_top_day_for_delete',
 'SELECT \'nothing to rename\' status');

PREPARE stmt FROM @query;

EXECUTE stmt;
</code></pre>

When you don't want to replace <code>[DATABASE NAME]</code> manually you can use the following variable

<pre><code>SELECT DATABASE() INTO @db_name FROM DUAL;
</code></pre>

blocks|key|436397|text|首先创建表IF+NOT+EXISTS。然后RENAME它，所以它将永远存在！|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|436398|否则，重命名该表，如果该表不存在，则处理该错误。|436399|这是显而易见的，但它是有效的。|436400|entityMap^0|5|D|L|6|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|R|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|K|$]]

First create table <code>IF NOT EXISTS</code>. Then <code>RENAME</code> it, so it will always exist! 

Otherwise, rename the table, and if it doesn't exist just handle the error.

It is obvious, but it works.

blocks|key|436345|text|目前还没有正式的解决方案。已经有feature+request在2004年提交，从未关闭|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|436346|entityMap|0|LINK|mutability|MUTABLE|url|http://bugs.mysql.com/bug.php?id=4754^0|G|F|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

There's no official solution yet. There has been <a href="http://bugs.mysql.com/bug.php?id=4754">feature request</a> submitted in 2004, never closed

blocks|key|650706|text|create+table+table2+like+table1;
insert+into+table2+select+*+from+table1;
drop+table+table1;|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|650707|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>create table table2 like table1;
insert into table2 select * from table1;
drop table table1;
</code></pre>

blocks|key|650976|text|如果你不想保留变量，你也可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|650977|DELIMITER+$$
IF+EXISTS+(SELECT+*
+++++++++++++++++++++FROM+INFORMATION_SCHEMA.TABLES
+++++++++++++++++++++WHERE+TABLE_SCHEMA+=+database()
+++++++++++++++++++++AND++TABLE_NAME+=+'oldname')
THEN
++++RENAME+TABLE+oldname+to+newname;
END+if;
$$
DELIMITER+;|code-block|syntax|javascript|650978|如果想要重用函数，甚至可以进一步创建该函数|650979|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

If you don't want to keep variables you can do also this:

<pre><code>DELIMITER $$
IF EXISTS (SELECT *
 FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_SCHEMA = database()
 AND TABLE_NAME = 'oldname')
THEN
 RENAME TABLE oldname to newname;
END if;
$$
DELIMITER ;
</code></pre>

You can even further create a function if you want to reuse it

blocks|key|436460|text|如果您熟悉PL/SQL，那么可以通过查询information_schema.columns来检查表是否存在，并在此基础上执行重命名|type|unstyled|depth|inlineStyleRanges|entityRanges|data|436461|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If you are familiar with PL/SQL, then you can check for existence of table by querying information_schema.columns and based on this perform rename

blocks|key|651027|text|解决方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|651028|CREATE+TABLE+IF+NOT+EXISTS+video_top_day;
RENAME+TABLE+video_top_day+TO+video_top_day_for_delete|code-block|syntax|javascript|651029|如果不存在，它会创建一个空表！|651030|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

a workaround :
<pre><code>CREATE TABLE IF NOT EXISTS video_top_day;
RENAME TABLE video_top_day TO video_top_day_for_delete
</code></pre>
it creates an empty table if not exists !

blocks|key|436664|text|DELIMITER+;;
DROP+PROCEDURE+IF+EXISTS+renameTableIfExists;;
CREATE+PROCEDURE+renameTableIfExists(IN+tbl+VARCHAR(255),+IN+toTbl+VARCHAR(255))
BEGIN
SELECT+DATABASE()+INTO+@db_name;
SELECT+Count(*)+INTO+@exists+FROM+information_schema.tables+
++WHERE+table_schema+=+@db_name
++++AND+table_type+=+'BASE+TABLE'
++++AND+TABLE_NAME+=+tbl;

IF+@exists+>+0+THEN
+++SET+@dropToTbl+=+CONCAT("DROP+TABLE+IF+EXISTS+",+toTbl);+PREPARE+dropToTbl+FROM+@dropToTbl;+EXECUTE+dropToTbl;
+++SET+@renameTbl+=+CONCAT("RENAME+TABLE+",+tbl,+"+to+",++toTbl);+PREPARE+renameTbl+FROM+@renameTbl;+EXECUTE+renameTbl;
+++SELECT+@tbl,+@toTbl;
ELSE+++
+++SELECT+'Table+not+exists';
END+IF;
END;;
DELIMITER+;

CALL+renameTableIfExists('Tags',+'Tags2');|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|436665|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre class="lang-sql prettyprint-override"><code>DELIMITER ;;
DROP PROCEDURE IF EXISTS renameTableIfExists;;
CREATE PROCEDURE renameTableIfExists(IN tbl VARCHAR(255), IN toTbl VARCHAR(255))
BEGIN
SELECT DATABASE() INTO @db_name;
SELECT Count(*) INTO @exists FROM information_schema.tables 
 WHERE table_schema = @db_name
 AND table_type = 'BASE TABLE'
 AND TABLE_NAME = tbl;

IF @exists &gt; 0 THEN
 SET @dropToTbl = CONCAT(&quot;DROP TABLE IF EXISTS &quot;, toTbl); PREPARE dropToTbl FROM @dropToTbl; EXECUTE dropToTbl;
 SET @renameTbl = CONCAT(&quot;RENAME TABLE &quot;, tbl, &quot; to &quot;, toTbl); PREPARE renameTbl FROM @renameTbl; EXECUTE renameTbl;
 SELECT @tbl, @toTbl;
ELSE 
 SELECT 'Table not exists';
END IF;
END;;
DELIMITER ;

CALL renameTableIfExists('Tags', 'Tags2');
</code></pre>

blocks|key|436540|text|将表oldtablename重命名为newtablename|type|unstyled|depth|inlineStyleRanges|entityRanges|data|436541|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

rename table oldtablename to newtablename

This <code>DROP TABLE IF EXISTS</code> works, too bad that <code>RENAME TABLE IF EXISTS</code> doesn't work.

Can anyone suggest a solution for this query?

<pre><code>You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IF EXISTS video_top_day TO video_top_day_for_delete' at line 1
</code></pre>

query:

<pre><code>RENAME TABLE IF EXISTS video_top_day TO video_top_day_for_delete
</code></pre>

Mysql: RENAME TABLE IF EXISTS

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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这个DROP TABLE IF EXISTS可以工作，但RENAME TABLE IF EXISTS不能工作，这太糟糕了。有人能为这个问题提供解决方案吗？You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax t

问Mysql:如果存在则重命名表
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回答 9

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问Mysql:如果存在则重命名表
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