Mysql:在以下情况下使用:删除表，截断表，从表中删除 [英] Mysql: Which to use when: drop table, truncate table, delete from table

问题描述

列出以下MySql命令之间的区别.

List the differences between the following MySql commands.

• 删除表表名;
• 截断表表名;
• 从表名中删除，其中1；

• drop table tablename;
• truncate table tablename;
• delete from tablename where 1;

也请根据您的经验告诉我每种产品的典型使用场景.

Also from your experiences please tell me typical usage scenario for each.

推荐答案

• drop table tablename;
  • 在此之后，它消失了.没有桌子了.没有更多数据.
  • 当您不再需要该表时使用它.
  • drop table tablename;
    • After this, it's gone. No more table. No more data.
    • Use this when you don't need that table any more.
    • 此后，该表为空，并且(重要地)自动递增键被重置为1.这从字面上看就像是拥有一个全新的表.
    • 当您只需要一个空表时，请使用此选项.它比DELETE更快，因为它只是删除所有数据. DELETE将扫描表以生成受影响的行数.
    • After this, the table is empty, and (importantly) auto-incrementing keys are reset to 1. It's quite literally like having a brand new table.
    • Use this when you just want an empty table. It's faster than DELETE because it simply deletes all data. DELETE will scan the table to generate a count of rows that were affected.
    • 这使您可以基于可选的WHERE子句来筛选要删除的行.
    • 要删除特定记录时使用此记录，例如:DELETE FROM tablename WHERE username = 'joe'
    • This lets you filter which rows to delete based on an optional WHERE clause.
    • Use this when you want to delete specific records, eg: DELETE FROM tablename WHERE username = 'joe'

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