1 queries executed, 0 success, 1 errors, 0 warnings 查询:create table emp( id int(8) primary key not null, ename varchar(20) not null, eage int(3), esex varchar(2) ) 错误代码: 1050 Table 'emp' already exists 执行耗时 : 0 sec 传送时间 : 0 sec 总耗时 : 0.001 sec 1. 2. 3....
1 queries executed, 0 success, 1 errors, 0 warnings 查询:create table emp( id int(8) primary key not null, ename varchar(20) not null, eage int(3), esex varchar(2) ) 错误代码: 1050 Table 'emp' already exists 执行耗时 : 0 sec 传送时间 : 0 sec 总耗时 : 0.001 sec 2、错误原因...
例如,已经存在emp表,执行:create table emp( id int(2)) ; 结果报错:ERROR 1050 (42S01): Table 'emp' already exists(意思是:emp表已经存在。) 而加了之后,即使表名已存在也不会报错,也会“执行”,但不会创建新的表。 例如,在第1点的基础上,执行:create table if not exists emp( id int(2)) ...
ON UPDATE CASCADE cannot be defined if an INSTEAD OF trigger ON UPDATE already exists on the table that is being altered. For example, in the AdventureWorks database, theProductVendortable has a referential relationship with theVendortable:ProductVendor.VendorIDforeign key references theVendor.Vendor...
CONSTRAINT CK_emp_id CHECK ( emp_id LIKE '[A-Z][A-Z][A-Z][1-9][0-9][0-9][0-9][0-9][FM]' OR emp_id LIKE '[A-Z]-[A-Z][1-9][0-9][0-9][0-9][0-9][FM]' ) This example specifies that the values must be within a specific list or follow a specified patte...
Example 4: Create an EMPLOYEE2 table with an identity column named EMP_NO. Define the identity column so that Db2 for i will always generate the values for the column. Use the default value, which is 1, for the first value that should be assigned and for the incremental difference between...
emp_id是自增的主键。 first_name和last_name是非空的字符串列。 hire_date的默认值为当前日期。 salary列必须大于零。 5.2 创建表与外键约束 创建一个订单表,并与员工表建立外键关系: CREATETABLEorders ( order_id SERIALPRIMARYKEY, emp_idINTREFERENCESemployees(emp_id)ONDELETECASCADE, ...
emp_id是外键,引用employees表的emp_id列。 order_date的默认值为当前时间。 total_amount列不能为空。 5.3 创建包含约束和默认值的表 创建一个包含复杂约束的表: CREATETABLEproducts(product_idSERIALPRIMARYKEY,product_nameVARCHAR(100)NOTNULLUNIQUE,priceNUMERIC(8,2)NOTNULLCHECK(price>0),stockINTDEFAULT0CHE...
CHECK ( emp_id IN ('1389', '0736', '0877', '1622', '1756') OR emp_id LIKE '99[0-9][0-9]' ) F. Show the complete table definition The following example shows the complete table definitions with all constraint definitions for table PurchaseOrderDetail created in the AdventureWorks20...
Oracle - PL/SQL if table not exist create, Hello i use oracle SQL developer I have create a procedure, and i need to check if a table exist, if not exist i must create how can do? I have try this DECLARE v_emp int:=0; BEGIN SELECT coun...