To add a column using SQL in Oracle, SQL Server, MySQL, and PostgreSQL, you can use the syntax shown here: ALTERTABLEtable_nameADD[COLUMN]column_name data_type[constraint]; All of these four databases (Oracle, SQL Server, MySQL, and PostgreSQL) use the same SQL add column syntax. So h...
{ ADD COLUMN <列名> <类型>-- 增加列ALTER TABLE 职员 ADD 年末奖金 Money NULL(为职员表添加列,列名为年末奖金,允许为空值,数据类型为货币数据类型。) | CHANGE [COLUMN] <旧列名> <新列名> <新列类型>-- 修改列名或类型 | ALTER [COLUMN] <列名> { SET DEFAULT <默认值> | DROP DEFAULT }-- ...
INSERT INTO:用于向数据库表中插入新数据。 INSERT INTO table_name(column1,column2,...)VALUES(value1,value2,...) table_name: 要插入数据的表。 column1, column2, ...: 要插入数据的列。 value1, value2, ...: 对应列的值。 UPDATE:用于更新数据库表中的现有数据。 UPDATE table_name SET colu...
To add a column in a table, use the following syntax: 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); ...
You can also create NOT NULL constraints on object type columns, and CHECK constraints that reference object type columns or any attribute of an object type column.See Also: constraints for syntax and description of these constraints, as well as examples...
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...
alteration ::= ADD [COLUMN] column-def The RENAME TO syntax is used to rename the table identified by [database-name.] table-name to new-table-name. This command cannot be used to move a table between attached databases, only to rename a table within the same database. ...
Use ALTER TABLE column_definition syntax to specify the properties of a column that are added to a table.
SQL_AD_ADD_CONSTRAINT_INITIALLY_IMMEDIATE(全级别) SQL_ALTER_TABLE 2.0 一个SQLUINTEGER 位掩码,用于枚举数据源支持的 ALTER TABLE 语句中的子句。必须支持此功能的 SQL-92 或 FIPS 一致性级别显示在每个位掩码旁边的括号中。以下位掩码用于确定支持哪些子句:SQL_AT_ADD_COLUMN_COLLATION = <支持添加列> 子句,...
ALTERTABLEtable_nameADDcolumn_name datatype --例如该员工表添加一列员工邮箱: altertablePeopleaddPeopleMail nvarchar(100) (2)如需在表中删除列,请使用下面的语法: ALTERTABLEtable_name DROPCOLUMNcolumn_name --例如删除员工表中的邮箱这一列 altertablePeople ...