1. `TRUNCATE TABLE`是一个DDL(数据定义语言)命令,因此它会隐式地提交当前事务。 2.由于`TRUNCATE TABLE`是一个快速的元数据操作,它通常比`DELETE`语句更快,尤其是在处理大型表时。 3.不能使用`TRUNCATE TABLE`删除具有外键约束的表中的数据,除非在定义外键约束时使用了`ON DELETE CASCADE`。 请注意,虽然`TRU...
TRUNCATETABLE[schema_name.]table_name[PRESERVE MATERIALIZEDVIEWLOG|PURGEMATERIALIZEDVIEWLOG][DROPSTORAGE|REUSE STORAGE]; SQL Server TRUNCATETABLE[schema_name.]table_name[WITH(PARTITIONS({<partition_number_expression>|<range>}[,...n]))]; MySQL TRUNCATETABLE[schema_name.]table_name; Postgres TRUNCATE...
Further, we’ll explore the practical usage of the TRUNCATE TABLE statement in SQL and delete thePersonstable data from theAdventureWorks2019database. First, let’s see how many rows the table contains. To do this, we’ll execute the SELECT query with the COUNT(*) function that returns the...
Define truncate. truncate synonyms, truncate pronunciation, truncate translation, English dictionary definition of truncate. tr.v. trun·cat·ed , trun·cat·ing , trun·cates 1. To shorten or reduce: The script was truncated to leave time for commercial
As a DBA I have found many occasions in testing of various SQL Server deployments and scripts where I need to load a database with data from a lower environment or where I need to alter a table that might already have data in it in such a way that I need to first eliminate the data...
when the table is not designed with cascading, but as far as I know there isn't in t-sql/...
hive> drop table if exists 表名;drop table if exists table_name; 三、删除库 hive> drop database if exists 库名; 注意如果库里有表会报错 解决这个错误有两种方法:一、就是很简单的将所有表先删除完,再删除库。 另外一种就是使用下述的方法:使用cascade关键字执行强制删库。drop database if exists ...
Conformance Rules: Without Feature F202, "TRUNCATE TABLE: identity column restart option", conforming SQL language shall not contain an <identity column restart option>. Microsoft SQL Server 2008 R2 varies as follows:This feature is absent from the [ISO/IEC9075-2:2008] standard....
truncate table 在功能上与不带 WHERE 子句的 delete语句相同:二者均删除表中的全部行。 但truncate 比 delete速度快,且使用的系统和事务日志资源少。 delete 语句每次删除一行,并在事务日志中为所删除的每行记录一项。所以可以对delete操作进行roll back
SQL Server数据库 在SQL Server数据库中,您可以使用sys.foreign_keys和sys.foreign_key_columns视图来查看外键约束的详细信息。以下是一个SQL查询示例,用于查找所有受sys_dict表约束的表和列: SELECTFK.nameASForeignKeyName,OBJECT_NAME(FK.parent_object_id)ASParentTableName,COL_NAME(FC.parent_object_id,FC.par...