Create a table with check constraint : Check « Table « Oracle PL/SQL TutorialOracle PL/SQL Tutorial Table Check SQL> SQL> create table employees 2 ( empno NUMBER(4) constraint E_PK 3 primary key 4 constra
添加主键约束:alter table 表名 add constraint 约束名 primary key (列名) 添加唯一约束:alter table 表名 add constraint 约束名 unique (列名) 添加默认约束:alter table 表名 add constraint 约束名 default(内容) for 列名 添加check约束:alter table 表名 add constraint 约束名 check(内容) 添加外键约束:a...
Bug #25660 CHECK constraints in Create Table Submitted: 17 Jan 2007 1:45Modified: 6 Nov 2009 17:12 Reporter: Sahaya Thivearaj Email Updates: Status: Duplicate Impact on me: None Category: MySQL Server: GeneralSeverity: S3 (Non-critical) Version: server version: 5.0.27-communityOS: ...
ActiveRecord::Migration.verbose=falseActiveRecord::Schema.definedocreate_table:posts,force:truedo|t|ifENV["T"]t.check_constraint"id > 0",name:"foo",validate:falseendendunlessENV["T"]add_check_constraint:posts,"id > 0",name:"foo",validate:falseendendclassBugTest<ActiveSupport::TestCasedeftest...
obclient>CREATETABLEtbl8(col1INT,col2INT,col3INT,CONSTRAINTequal_check1CHECK(col2=col3*2)ENABLEVALIDATE);Query OK,0rowsaffected 为表ref_t2指定外键,当DELETE操作影响与子表相匹配行的父表中键值时,执行SET NULL操作。 obclient>CREATE TABLE ref_t1(c1 INT PRIMARY KEY,C2 INT);Query OK,0rows aff...
CREATETABLEOrders(OrderIDINTUNIQUENOTNULL,OrderItemVARCHAR,OrderQuantityINT,CustomerNumINT,CONSTRAINTOrdersPKPRIMARYKEY(OrderID),CONSTRAINTCustomersFKFOREIGNKEY(CustomerNum)REFERENCESCustomers(CustID)) 最常见的情况是,外键引用另一个表的主键字段。但是,外键可以引用RowID(ID)或标识列。在任何情况下,外键引用都必须...
CREATE TABLE 使用 Hive 格式 CREATE TABLE CONSTRAINT CREATE TABLE 使用中 CREATE TABLE LIKE CREATE VIEW CREATE VOLUME DECLARE VARIABLE DROP CATALOG DROP CONNECTION DROP CREDENTIAL DROP DATABASE DROP FUNCTION 投遞地點 DROP PROVIDER DROP PROCEDURE(刪除程序) DROP RECIPIENT DROP SCHEMA DROP SHARE DRO...
constraint-choices PRIMARY KEYUNIQUEreferences-clauseCHECK(check-condition) references-clause REFERENCES table-name (,column-name) check-condition search-conditionfunctional-dependency functional-dependency column-name(,column-name) DETERMINED BY column-name(,column-name) constraint-attributes ● NOT ENFORCE...
CONSTRAINT constraint_name 列约束或表约束的名字。可选的约束子句用于声明约束,新行或者更新的行必须满足这些约束才能成功插入或更新。 定义约束有两种方法: 列约束:作为一个列定义的一部分,仅影响该列。 表约束:不和某个列绑在一起,可以作用于多个列。 - LIKE source_table [ like_option ... ] LIKE子...
The CREATE TABLE statement defines a table. The definition must include its name and the names and attributes of its columns. The definition can include other attributes of the table, such as its primary key or check constraints.