openGauss每日一练第 14 天

原创蓝图赵 2022-12-07

129

1.创建表的时候定义列级约束

Create table t1(col1 bigint primary key,name varchar(10) not null);

Insert into t1 values(1,’u1’);

Select * from t1;

Create table t2(col1 bigint,name varchar(10) not null,primary key(col1));

Insert into t2 values(2,’u2’);

Select * from t2;

Create table t3(col1 int,name varchar(10) default ‘noman’);

Insert into t3 values(3);

Select * from t3;

Create table t4(col1 int primary key,name varchar(10));

Insert into t4 values(4);

Select * from t4;

Create table t5(col1 serial notnull,name varchar(20));

Insert into t5(name) values(‘u51’);

Insert into t5(name) values(‘u52’);

Insert into t5(name) values(‘u53’);

Select * from t5;

Create table t6 as select * from t5;

Select * from t6;

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