限制插入到表中的行数 [英] Limit number of Rows inserted into a Table

问题描述

我们如何限制一个表的行数是固定的?例如，如果我将 Limit 设为 20，则可以将 20 行插入其中，然后该表应指示已超出限制.

How can we restrict a table to have fixed number of rows? for example if i give Limit as 20, then 20 rows can be inserted into it and after that table should indicate the limit has been exceeded.

示例:如果我们创建一个触发器

EXAMPLE: IF we create a trigger

 CREATE TRIGGER log AFTER INSERT ON TEST_TABLE
 BEGIN
 INSERT INTO TEST_TABLE VALUES(....);
 SELECT COUNT(COL) FROM TEST_TABLE;
 END;

一旦我在表格中输入一行，这并没有给我计数.

This is not giving me the count as soon as i enter a row into the table.

推荐答案

在插入那个表之前创建触发器.在触发器中，您可以检查同一个表中的记录计数.

Create a Trigger before Insert on That table. In Trigger you can check for count for records that same table has.

检查此链接以创建触发器.

Check this link for Creating Trigger.

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