alter table 表名 modify 字段名 类型 null 默认值约束 default 添加默认值约束:alter table 表名 alter 字段名 set default 默认值 删除默认值约束:alter table 表名 alter 字段名 drop default 引用完整性(参照完整性): 外键约束:FOREIGN KEY: 添加外键约束:alter table 从表
ConstraintEnforcement ConstraintNames ExistingRowsCheckEnforcement 方法 AlterTableDropTableElement AlterTableDropTableElementStatement AlterTableFileTableNamespaceStatement AlterTableRebuildStatement AlterTableSetStatement AlterTableStatement AlterTableSwitchStatement AlterTableTriggerM...
{ CASCADE | NO ACTION | SET DEFAULT |SET NULL } ] } < table_constraint > ::= [ CONSTRAINT constraint_name ] { [ { PRIMARY KEY | UNIQUE } { ( column [ ,...n ] ) } | FOREIGN KEY ( column [ ,...n ] ) REFERENCES ref_table [ (ref_column [ ,...n ] ) ] [ ON ...
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.
1.语法:ALTER TABLE 表名 ADD CONSTRAINT 主键名 PRIMARY KEY 表名(主键字段); 3.添加外键 1.语法:ALTER TABLE 表名 ADD CONNSTRAINT 外键名 FOREIGN KEY(外键字段) REFERENCES 关联表名(关联字段); 4.插入单(多)条数据记录(和SQL Server相同,但是不能用select多列添加数据) ...
ALTER TABLE ändert eine Tabellendefinition durch Ändern, Hinzufügen oder Löschen von Spalten und Einschränkungen. Mit ALTER TABLE können Sie zudem Partitionen neu zuweisen und erstellen oder Einschränkungen und Trigger deaktivieren und
AlterTableAlterColumnStatement 建構函式 屬性 AlterTableAlterColumnOption 定序 ColumnIdentifier DataType 加密 GeneratedAlways IsHidden IsMasked MaskingFunction 選項 StorageOptions 方法 AlterTableAlterIndexStatement AlterTableAlterPartitionStatement AlterTableChangeTrackingModificationStatement AlterTableC...
Namespace: Microsoft.SqlServer.TransactSql.ScriptDom Assembly: Microsoft.SqlServer.TransactSql.ScriptDom (in Microsoft.SqlServer.TransactSql.ScriptDom.dll)SyntaxC# העתק [SerializableAttribute] public class AlterTableConstraintModificationStatement : AlterTableStatement ...
ALTER TABLE table_name ALTER COLUMN column_name { type_name[({precision[.scale]})][NULL|NOT NULL] {DROP DEFAULT | SET DEFAULT constant_expression | IDENTITY [ ( seed , increment ) ] } | ADD { < column_definition > | < table_constraint > } [ ,...n ] | DROP { [ CONSTRAINT ]...
Modifies an existing table or view index (rowstore, columnstore, or XML) by disabling, rebuilding, or reorganizing the index; or by setting options on the index. Transact-SQL syntax conventions Syntax Syntax for SQL Server, Azure SQL Database, and Azure SQL Managed Instance. syntaxsql Copy ...