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) 1.INSERT INTO 表名[(字段名...
ALTERTABLE[IFEXISTS]table_name {ADD{<schema_component>|(<schema_component>[,...])}|MODIFY{<schema_component>|(<schema_component>[,...])}|DROP{column_name|(column_name,column_name,...)|PRIMARYKEY|CONSTRAINTconstraint_name|WATERMARK}|RENAMEold_column_nameTOnew_column_name|RENAMETOnew_table_...
CONSTRAINT PRIMARY KEY [索引类型] (<列名>,…) 在CREATE TABLE 语句中添加此语句,表示在创建新表的同时创建该表的主键。 【实例2】创建一个表 tb_stu_info2,在该表的 id 字段上使用 PRIMARY KEY 关键字创建主键索引。 语法格式: KEY | INDEX [<索引名>] [<索引类型>] (<列名>,…) 在CREATE TABLE ...
DROP CONSTRAINT (删除约束),语法如下: ALTERTABLEtable_nameDROPCONSTRAINTMyUniqueConstraint; 如果是 MYSQL ,代码是这样: ALTERTABLEtable_nameDROPINDEXMyUniqueConstraint; DROP PRIMARY KEY (删除主键),语法如下: ALTERTABLEtable_nameDROPCONSTRAINTMyPrimaryKey; 如果是 MYSQL ,代码是这样: ALTERTABLEtable_nameDROPP...
The PRIMARY KEY constraint in the user table can't be modified while a spatial index is defined on a column of that table. To change the PRIMARY KEY constraint, first drop every spatial index of the table. After modifying the PRIMARY KEY constraint, you can re-create each of the spatial...
在修改表时,设置检查约束可以使用的SQL语句是()A、 Primary Key(主键名)B、ALTER TABLE 表名 ADD CONSTRAINT 检查约束名 check (约束条件)C、FOREIGN KEY REFERENCES主键表名(主键字段名)D、constraint 主键约束名 Primary Key(主键名)搜索 题目 在修改表时,设置检查约束可以使用的SQL语句是() A、 Primary Key...
The PRIMARY KEY constraint in the user table can't be modified while a spatial index is defined on a column of that table. To change the PRIMARY KEY constraint, first drop every spatial index of the table. After modifying the PRIMARY KEY constraint, you can re-create each of the spatial...
The PRIMARY KEY constraint in the user table can't be modified while a spatial index is defined on a column of that table. To change the PRIMARY KEY constraint, first drop every spatial index of the table. After modifying the PRIMARY KEY constraint, you can re-create each of the spatial...
在修改表时,设置外键可以使用的SQL语句是()。A.FOREIGN KEY REFERENCES主键表名(主键字段名)B.ALTER TABLE 表名 ADD CONSTRAINT外键约束名 FOREIGN KEY(外键字段名)REFERENCES 主键表名(主键字段名)C.constraint 主键约束名 Primary Key(主键名)D.Primary Key(主键名)...
N. Dropping a PRIMARY KEY constraint in the ONLINE mode The following example deletes a PRIMARY KEY constraint with the ONLINE option set to ON. SQL Copy USE AdventureWorks; GO ALTER TABLE Production.TransactionHistoryArchive DROP CONSTRAINT PK_TransactionHistoryArchive_TransactionID WITH (ONLINE =...