ALTER TABLE table_name ALTER COLUMN column_name modification_type; Code language: SQL (Structured Query Language) (sql) In this syntax: First, specify the name of the table which you want to perform the change in the ALTER TABLE clause. Second, specify the name of the column that you want...
云原生数据仓库 AnalyticDB MySQL 版支持通过ALTER TABLE修改表结构,包括修改表名、列名、列类型、普通索引、聚集索引、外键索引、分区函数的格式、冷热分层存储策略。本文介绍ALTER TABLE语法。 语法 ALTER TABLE table_name { ADD [COLUMN] column_name column_definition | ADD [COLUMN] (column_name column_definitio...
ALTERTABLEtable_name ADDcolumn_name datatype; The following SQL adds an "Email" column to the "Customers" table: ExampleGet your own SQL Server ALTERTABLECustomers ADDEmail varchar(255); ALTER TABLE - DROP COLUMN To delete a column in a table, use the following syntax (notice that some da...
syntaxsql コピー ALTER TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } { ALTER COLUMN column_name { [ type_schema_name. ] type_name [ ( { precision [ , scale ] } ) ] [ COLLATE collation_name ] [ NULL | NOT NULL ] } | ALTER INDEX inde...
To rename a column, MySQL provides syntax: ALTER TABLE CHANGE ... which requires re-specification of all the attributes of the column. Disadvantages of the above syntax : - All the column information might not be available to the application trying to do the rename. - There is a risk of...
ALTER TABLE modifies a table definition by altering, adding, or dropping columns and constraints. ALTER TABLE also reassigns and rebuilds partitions, or disables and enables constraints and triggers.
ALTER TABLE table_name { ADD COLUMN clause | ALTER COLUMN clause | DROP COLUMN clause | RENAME COLUMN clause } ADD COLUMN 子句JDBC 数据源不支持此子句。向表添加一列或多列,或将字段添加到 Delta Lake 表中的现有列。备注 向现有 Delta 表添加列时,无法定义 DEFAULT 值。 对于现有行,...
Groups of ALTER TABLE syntax: alter_table_properties::= column_clauses::= constraint_clauses::= alter_table_partitioning::= alter_external_table_clauses::= move_table_clause::= enable_disable_clause::= After each clause you will find links to its component subclauses. ...
ALTER TABLE table_name RENAME TO new_table_name; For Example: ALTER TABLE suppliers RENAME TO vendors; This will rename thesupplierstable tovendors. Adding column(s) to a table Syntax #1 To add a column to an existing table, the ALTER TABLE syntax is: ...
Note that it is proper syntax to have multiple partition_spec in a single ALTER TABLE, but if you do this in version 0.7, your partitioning scheme will fail.That is, every query specifying a partition will always use only the first partition. Instead, you should use the following form if...