1、建表 CREATEDATABASEdel;usedel;CREATETABLEex(idINTNOTNULLPRIMARYKEYauto_increment,nameVARCHAR(10)UNIQUE);---CREATETABLEex_2(idINTNOTNULLPRIMARYKEYauto_increment,nameVARCHAR(10)UNIQUE); 2、插入数据 INSERTINTOexVALUES(1,'name');INSERTINTOex_2VALUES(1,'name'); -- 插入多条INSERTINTOex(name)...
DELETE FROM table_1 WHERE id = %s; To bind value value1 to the placeholder, you call the execute() method and pass the input value as a tuple to the second parameter like the following: cur.execute(delete_sql, (value1,)) After that, save the changes to the database permanently by ...
To delete data in your book_awards table, use the DELETE statement. You can delete data from a row or from a partition. Be careful when deleting data, because deletions are irreversible. Deleting one or all rows from a table doesn't delete the table. Thus you can repopulate it with data...
所以要想达到释放磁盘空间的目的,delete以后执行optimize table 操作。 示例:查看表占用硬盘空间大小的SQL语句如下:(用M做展示单位,数据库名:csjdemo,表名:demo2) select concat(round(sum(DATA_LENGTH/1024/1024),2),'M') as table_size from information_schema.tables where table_schema='csjdemo' AND tabl...
DROP TABLE的功能是用来删除已存在的Table。 2、语法 DROP TABLE [IF EXISTS] [db_name.]table_name; 说明:SQL中加[IF EXISTS] ,可以防止因表不存在而导致执行报错。 参数:db_name:Database名称。如果未指定,将选择当前database。table_name:需要删除的Table名称。
DELETE FROM 表名 [WHERE 条件]; TRUNCATE 表名;TRUNCATE是DDL语句,它只能删除表中的所有数据,不能根据条件删除,也不能删除表结构; DROP TABLE 表名;直接删除表; 如果表中含有外键约束,DDL语句不能直接删除表,只能先删除外键约束才能删除表。 DQL 数据查询语言(Data QueryLanguage,DQL)用于查询数据,以SELECT为核...
Delete comma from table column data Delete data from all tables in a schema Delete data in Excel using Openrowset? Delete from Where Exists DELETE From with sub query delete large number of rows without growing the transaction log Delete Query is Performing too slow with around 6 million records...
selectconcat(round(sum(DATA_LENGTH/1024/1024),2),'M')astable_size frominformation_schema.tables wheretable_schema='csjdemo'ANDtable_name='demo2'; 然后执行空间优化语句,以及执行后的表Size变化: 1 optimizetabledemo2 再看看这张表的大小,就只剩下表结构size了。
DROP TABLE[IF EXISTS][db_name.]table_name; 1. 说明:SQL中加[IF EXISTS] ,可以防止因表不存在而导致执行报错。 参数:db_name:Database名称。如果未指定,将选择当前database。table_name:需要删除的Table名称。 3、示例 以下示例演示DROP命令的使用,依次执行如下SQL语句: ...
Solved: Hallow I build a table in se11 that I can put on her data from my itab how can I clean the table before I put a new data. I try with delete but its not working