Mysql 是否与 mssql 中的 @@ROWCOUNT 等效？
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Does Mysql have an equivalent to @@ROWCOUNT like in mssql?
提问by abs
How can I get row count values in MySQL as @@ROWCOUNTdoes in mssql?
如何像@@ROWCOUNT在 mssql 中一样在 MySQL 中获取行计数值？
回答by AndiDog
For SELECTs you can use the FOUND_ROWSconstruct (documented here):
对于 SELECT，您可以使用FOUND_ROWS构造（此处记录）：
SELECT SQL_CALC_FOUND_ROWS something FROM your_table WHERE whatever;
SELECT FOUND_ROWS( ) ;
which will return the number of rows in the last SELECTquery (or if the first query has a LIMITclause, it returns the number of rows there would've been without the LIMIT).
这将返回最后一个SELECT查询中的行数（或者如果第一个查询有一个LIMIT子句，它将返回没有LIMIT.的行数）。
For UPDATE/DELETE/INSERT, it's the ROW_COUNTconstruct
对于UPDATE/ DELETE/ INSERT，它的ROW_COUNT结构
INSERT INTO your_table VALUES (1,2,3);
SELECT ROW_COUNT();
which will return the number of affected rows.
这将返回受影响的行数。
回答by Lazarus
回答by Yada
The simplest way would be to use a variable:
最简单的方法是使用变量：
mysql> SELECT @rowcount:=COUNT(*) FROM my_table;
mysql> SELECT @rowcount;
Or you can use FOUND_ROWS()construct after putting a SQL_CALC_FOUND_ROWS in a SELECT statement.
或者您可以FOUND_ROWS()在 SELECT 语句中放入 SQL_CALC_FOUND_ROWS 后使用构造。
mysql> SELECT SQL_CALC_FOUND_ROWS * FROM my_table;
mysql> SELECT FOUND_ROWS();
回答by Rolf
There is another way:
还有一种方法：
CREATE TEMPORARY TABLE `results` AS ( *** Your query without LIMIT *** );
Get the row count
获取行数
SELECT COUNT(*) FROM `results`;
Get your subset
获取您的子集
SELECT * FROM `results` LIMIT 5,10;
The temporary table exists only in the current session. I would still clean-up afterwards
临时表只存在于当前会话中。之后我仍然会清理
DROP TEMPORARY TABLE `results`;
