Drop NOT NULL constraints Sometimes, you need to change a column with aNOT NULLconstraint to accept NULL values. To do this, you need to remove theNOT NULLconstraint from the column by using theALTER TABLEstatement as below: ALTERTABLEtable_nameMODIFY( column_nameNULL)Code language:SQL (Struc...
--列级约束hire_date date not null, dept_id number(8), email varchar2(8) constraint emp1_email_uk unique, name varchar2(8) constaint emp1_name_uu not null, first_name varchar2(8), --表级约束constraint emp1_emp_id_pk primary key(employee_id), constraint emp1_fir_name_uk unique(...
alter table tb_name add column datatype[defaultval]constraint... 说明: 1.如果添加not null(primary key约束要求值也不能为null)约束,需要保证当前表中没有数据存在 2.新添加的列,相当于表定义中最后一个定义的列。 例如: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 alter table test add nameva...
This may occur because there are two instances of the same Oracle home directory in thetnsnames.orafile. To resolve this issue open the%ORACLE_HOME%/omwb/network/admin/tnsnames.orafile, and remove the second instance of the Oracle home Data Migration This section contains Migration Workbench data...
If any SQL operation leaves a NULL value in a column with a NOT NULL constraint, Oracle returns an error for the statement. Unique When you designate a column or set of columns as unique, users cannot add values that already exist in another row in the table for those columns, or ...
not、now、null、nulls、object、of、on、operator、or、order、orderbytop、output、partition、partitionwin、partnwin、passing、path、pattern、patternstrm、patternstrmb、prev、primary、project、push、query、queue、range、rangewin、real、register、relation、relsrc、remove、return、returning、rows、rowwin、rstream...
Either remove the unique restriction or do not insert the key. 如果分析确定此处唯一约束或主键约束不需要,那么则可使用下面语句删除约束 -- 查询约束与索引信息selecta.owner 约束所有者, a.constraint_name 约束名,casea.constraint_typewhen'P'then'Primary key'when'U'then'Unique key'when'C'then' Check...
ORA-13410: NULL 列名 ORA-13411: Oracle 列 "" 不存在。 ORA-13412: 无效的 ROWID ORA-13413: 无法选择初始化的 GeoImage ORA-13414: 无法更新包含 GeoImage 的表 ORA-13415: 无效的域 ORA-13416: 无效的几何结构,参数 [] ORA-13417: 未定义的模型空间转换光栅 ...
T1033 ( ROLLOUT_PLAN_LINE_ID NUMBER NOT NULL ,UDF_FIELD_VALUE_ID NUMBER NOT NULL ,CONSTRAINT UDF_FIELD_VALUE_ID_PK UNIQUE (UDF_FIELD_VALUE_ID) ) ; NULL约束 在以下包中声明局部变量时不支持NULL约束: L_CONTRACT_DISTRIBUTE_STATUS SAD_DISTRIBUTION_HEADERS_T.STATUS%TYPE NULL ; 输入 1 2 3...
You can add any constraint on a Global Temporary Table except FOREIGN KEYS. CREATE GLOBAL TEMPORARY TABLE t2 ( c1 serial PRIMARY KEY, c2 VARCHAR (50) UNIQUE NOT NULL, c3 boolean DEFAULT false ) The use of FOREIGN KEYS in a Global Temporary Table is not allowed. ...