You substitute in the old name or the current name of the table, and the new name of the table, then run the command. For example, to rename the “employee” table to “person”, you can run this command: ALTER
LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)] LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)] 1. 2. Load 操作只是单纯的复制/移动操作,将数...
NoteCandidate indexes (created by including the UNIQUE option, provided for ANSI compatibility in ALTER TABLE or CREATE TABLE) are not the same as indexes created with the UNIQUE option in the INDEX command. An index created with UNIQUE in the INDEX command allows duplicate index keys; candidate...
The ALTER TABLE command allows you to add, modify, or drop a column from an existing table. Adding column(s) to a table Syntax #1 To add a column to an existing table, the ALTER TABLE syntax is: ALTER TABLE table_name ADD column_name column-definition; For example: ALTER TABLE supplie...
RENAME TABLE renames a specified table.RENAME TABLE has the same function as the following command:schemaSpecifies the schema name.Specifies the schema name.table_nameSpe
RENAME TABLE是一个DDL(Data Definition Language)语句,用于定义或修改数据库结构。 应用场景: 当你需要对数据库中的表进行重构或优化时。 当你需要避免表名冲突时。 当你需要将表迁移到另一个数据库或服务器时。 可能遇到的问题及解决方法: 表名冲突:如果你尝试将表重命名为一个已经存在的表名,MySQL会报错。解...
exec sp_msforeachtable @command1=' declare @o sysname,@n sysname select @o=''?'' ,@n=stuff(@o,1,charindex(''].[fg_'',@o)+6,''fgjzw_'') ,@n=left(@n,len(@n)-1) exec sp_rename @o,@n', @whereand=' and o.name like ''fg_%''' ...
For example, to reclaim the space occupied by a deleted column, the fastest method is to use the command. ALTER TABLE table ALTER COLUMN anycol TYPE anytype; In this command, anycol indicates any column existing in the table and anytype indicates the type of the prototype of the column...
Table:「Rename」、「Copy」(別の名前を使用してコピーを作成)、「Drop」(表を削除)、「Truncate」(表定義に影響を与えることなく既存のデータを削除)、「Lock」(行共有、排他などの表ロック・モードを設定)、「Comment」(表の使用方法や目的を説明するコメント)、「Parallel」(表での問合せおよび...
show table status like 'zz_users'\G;:纵排输出一张表的状态信息。 alter table 表名 表选项;:修改一张表的结构,如alter table xxx engine=MyISAM。 rename table 表名 to 新表名;:修改一张表的表名。 alter table 表名 字段操作;:修改一张表的字段结构,操作如下: add column 字段名 数据类型:向已有...