后台服务测试过程中,发现往Oracle数据库表中插数据出现一个错误 unique constraint,如下: ### Error updating database. Cause:Java.sql.SQLIntegrityConstraintViolationException:ORA-00001: unique constraint (TEST53.SYS_C0032604) violated ### The error may exist in class path resource [sqlmapper/ACMClaimMa...
1、直接本地连接 # 连接已有表空间 sqlplus wateruser/itcast@orcl 1. 2. 2、IP连接oracle 在sqlplus.exe所在目录下,执行如下命令: sqlplus 表空间/用户名@//地址:1521/orcl(实例名/全局数据库名,每个oracle数据库可以创建多个实例) sqlplus wateruser/itcast@//192.168.80.10:1521/orcl 1. ORACLE中的索引 什...
Some of the fields can contain null values as long as the combination of values is unique.Note In Oracle, a unique constraint can not contain more than 32 columns. A unique constraint can be defined in either a CREATE TABLE statement or an ALTER TABLE statement....
Unless a NOT NULLconstraint is also defined, a null always satisfies a unique key constraint. Thus,columns with both unique key constraints and NOT NULL constraints are typical.This combination forces the user to enter values in the unique key andeliminates the possibility that new row data confl...
SQL> insert into test2 values(1,'a'); 此处一直处于等待状态。 然后将session 1提交,这时session 2报错。 下面dump片断是在sesson 2处于等待状态时的10046跟踪结果: === PARSING IN CURSOR #2 len=31 dep=0 uid=34 oct=2 lid=34 tim=10705648912 hv=4047255222 ad='277dc964' sqlid='9u2g41msmsdpq'...
(至少在oracle上建立外键,不会自动建立index),因此创建key也有如下几种方式: (1)在字段级以key方式建立, 如 create table t (id int not null primary key); (2)在表级以constraint方式建立,如create table t(id int, CONSTRAINT pk_t_id PRIMARY key (id)); ...
SQL Server / Oracle / MS Access: ALTERTABLEPersons DROPCONSTRAINTUC_Person; Exercise? What does the SQLUNIQUEconstraint ensure? That a column cannot contain NULL values That all values in a column are different That a column must always contain a value ...
SQL FunctionSQL- unique constraint : Unique constraint is used to ensure that the values in the columns are distinct are not.It provides a guarantee for uniqueness in a column or set of columns. UNIQUE and PRIMARY KEY constraints both provide a guarantee for uniqueness for a column or set ...
SQL> insert into test2 values(1,'a');此处一直处于等待状态。然后将session 1提交，这时session 2报错。下面dump片断是在sesson 2处于等待状态时的10046跟踪结果：=== PARSING IN CURSOR #2 len=31 dep=0 uid=34 oct=2 lid=34 tim=10705648912 hv=4047255222 ad='277dc964' sqlid='9u2g41m...
Inserting a record with the samepurchased_by_idandtransferred_from_idvalues again should result in a SQL error: INSERTINTOticket_purchase_histVALUES(6,1,1,6,6,'2020-07-05'::DATE); We get the following output: SQLError[23505]: ERROR:duplicatekey...